We devulcanized ground tire rubber (GTR) in a laboratory microwave oven and an internal mixer, measured the soluble content and the cross-link density of the samples, and then used Horikx’s analysis. The results showed that microwave treatment caused severe degradation of the polymer chains, while in the case of thermomechanical devulcanization, the selective scission of covalent cross-links is more common. Four devulcanized ground tire rubber (dGTR) samples were chosen for further study and three groups of samples were produced: dGTR samples containing vulcanizing agents and different amounts of paraffin oil (dGTR-based mixtures), natural rubber-based rubber mixtures with different dGTR contents and reference rubber mixtures with dGTR-based mixtures (increased vulcanizing agent contents). Cure characteristics showed a plasticizer-like effect of dGTR. Tensile and tear strength decreased drastically with increasing dGTR content; however, elongation at break values did not follow such a trend. Mechanical properties improved with increased vulcanizing agent contents. The examined properties of the samples improved even further with the use of thermomechanically devulcanized samples. Horikx’s analysis showed that this is attributable to moderate polymer chain scission. Therefore, many studies focus on the reclamation and recycling of waste rubber products and tires, but reuse and recycling are a challenge due to the 3D cross-linked structure of rubbers. According to the EU waste hierarchy, the reuse of these products is a favorable solution. However, existing approaches, such as the application of waste tires as safety barriers on racetracks and retreading tires, creates new products of reduced quality and functionality.The amount of waste rubber products, especially that of waste tires, is rapidly increasing. The traditional methods of waste tire management have been stockpiling or landfilling, both of which are short-term solutions and pose significant health and environmental problems3.Another way to use scrap rubber is to burn it in furnaces or convert it to liquid fuel in pyrolysis reactors in an oxygen-free environment. Tires have a high heat value (ca. 32.6 MJ/kg), which is even higher than that of coal (ca. 18.6–27.9 MJ/kg). The end product of pyrolysis is carbon black and an oil-like material, which can be processed like petroleum4, which can be produced in different ways: mechanical grinding at ambient or cryogenic temperatures5, and waterjet milling. In waterjet milling, a high-pressure water beam grinds rubber waste. Compared to mechanical grinding, smaller particles can be obtained, and rubber degradation can also be avoided, though the final material needs to be dried.The best way of disposing of waste tires and other rubber products is to turn them into a ground powder 5 or thermoset9 polymers with or without compatibilization11. However, the volume of these applications cannot meet the ever-increasing need for rubber recycling.GTR can be used as an additive without any physical or chemical treatment in asphalt and can be bound together with polyurethane. GTR can be blended with thermoplastic15, enhancing adhesion between devulcanized GTR (dGTR) particles and other polymers. Consequently, the amount of recycled rubber in new rubber products can be increased without compromising their mechanical properties. Conventional devulcanization techniques, such as thermomechanical17, thermochemical18, mechanochemical19, and microwave23 devulcanization, have decades-long history of research24. There are other devulcanization methods utilizing ultrasound26, chemolithotrophic bacteria27, and supercritical carbon dioxide28. Each method has its advantages and disadvantages. Microwave-treated GTR has good properties, and the technique has a promise of high productivity. Microwave devulcanization takes advantage of volumetric heating: a fast and uniform rise in temperature can be achieved. The selective scission of sulfuric cross-links is possible with the right parameters . The process does not require additional chemicals and is considered an eco-friendly technology. A major drawback of microwave devulcanization is that nonpolar elastomers like NR, styrene-butadiene rubber (SBR) or ethylene propylene diene monomer rubber (EPDM), have low microwave absorbance. However, carbon black, which is often used as a filler in rubber products14, has good microwave absorbance and dissipates its energy in the form of heat29.Devulcanization may offer a solution to this problem. This process is suitable to selectively break covalent cross-links in elastomeric materials, keeping the polymer backbone intact. New molecules form, and they can create new bonds on the surface of the GTR particles13. Garcia et al.20 devulcanized GTR with microwaves and were able to increase the sol fraction from 14 to 31% after 7 min of treatment. They determined that in addition to the breaking of S–S and C–S bonds, the main chain was also degraded. However, sol fraction on its own is not a sufficient indicator of devulcanization. The cross-link density of dGTR is also an essential factor. The degree of devulcanization can be defined as the percentage decrease in the cross-link density of a sample. De Sousa et al.10 found that the higher the amount of energy absorbed during the treatment, the higher the final temperature of the GTR, hence the higher the decrease in cross-link density. The FTIR analysis of dGTR can also reveal the structural changes that take place during devulcanization21. Therefore, FTIR is a suitable supporting method.The effectiveness of devulcanization can be evaluated with the soluble content of the rubber sample. It can be directly measured via Soxhlet extraction, during which a small amount of organic solvent is repeatedly distilled to dissolve the soluble components of a solid material. Many studies, addressing microwave devulcanization, focused on the effect of different exposure times of GTR to microwaves. The accepted conclusion was that the longer the exposure time, the larger the soluble fraction (sol fraction) of the samples30 is a commonly accepted method that establishes a mathematical relationship between the sol fraction and the degree of devulcanization. Ultimately, it can indicate whether the main phenomenon during devulcanization is random scission of the polymer chains or selective scission of the covalent cross-links31. Horikx’s analysis is becoming a widely used method to grade devulcanization. There are many examples of its use in scientific literature: assessing microwave devulcanization of recycled NR32, thermomechanical devulcanization of GTR33, thermochemical devulcanization of NR and EPDM34 and microbiological devulcanization of NR35.Horikx’s analysis36. Furthermore, we added dGTR to polypropylene-based thermoplastic dynamic vulcanizates (TDV) to verify our method as a means of GTR recycling. We found that virgin rubber can be replaced with up to 20 wt% devulcanizate without compromising the mechanical properties of the resulting TDV37.In our previous article, we showed the effects of different GTRs  with different particle sizes on the devulcanization process and optimized the parameters of microwave devulcanizationIn this study, we compared the applicability of microwave-devulcanized and mechanically devulcanized GTR in virgin NR. First, we selected the ideal devulcanizates for further study based on Horikx’s analysis. We produced NR-based mixtures incorporating various amounts of the four selected dGTR samples. Finally, we tested the mechanical and physical properties of the resulting rubber samples to determine the effectiveness of our recycling processes.Waterjet-milled crumb rubber was provided by Aquajet Ltd. . The material originated from the tread area of truck tires. Therefore, this type of GTR is a high-purity material. According to TGA measurements, it contains 50–55 phr of NR, 45–50 phr of synthetic rubber, 4–6 phr of oil, 33–37 phr of carbon black, and 7.5 phr of residual additives. We chose a general-purpose natural rubber for our investigations. Table 36.The additives of rubber mixtures and their suppliers were the following: zinc oxide , stearic acid , N772 carbon black , paraffin oil , tetramethyl thiuram disulfide , N-cyclohexyl-2-benzothiazole sulfonamide  and sulfur . The particle size distribution of GTR was published in our previous paperMicrowave devulcanization of GTR was carried out in a BP-125/50 type laboratory microwave oven, produced by Microwave Research Inc. . We heated 50 and 100 g batches of GTR up to 200 °C with a heating rate of 6 °C/min. The microwave power was controlled by a PID controller that used data from a thermocouple that was continuously measuring the temperature of the rubber inside the oven. A motorized stirring system was installed to the microwave oven to insure homogeneous temperature. After the temperature reached 200 °C, the material was taken out and allowed to cool to room temperature. In some cases, the samples were heat-treated at 140 °C in a Venticell LSIS-B2V  laboratory oven prior to devulcanization. The parameters of microwave devulcanization, and the nomenclature of the samples can be seen in Table 3. The parameters of thermomechanical devulcanization and the abbreviations of the samples are listed in Table Thermomechanical devulcanization was performed in a Brabender Plasti-corder internal mixer . The duration of the treatment was 10 min, and the chamber volume was 50 cmMi and Mf stand for the mass of rubber before and after the extraction, respectively.GTR and dGTR were characterized by Soxhlet extraction in toluene, according to Eq. . The ins38 after equilibrium swelling (72 h followed by drying to constant mass at 80 °C) in toluene.3); V1 is the molar volume of the solvent (for toluene: 106.13 cm3/mol); Vr means the volume fraction of rubber in the swollen sample, which can be determined with the Ellis and Welding Eq. (31.ms is the mass of the swollen rubber sample (g), mr is the mass of the dry rubber sample (g), 3) and 3).The cross-link density of untreated GTR and devulcanizates was determined via swelling tests according to ASTM D 297-15. We calculated the cross-link density values using the Flory-Rehner Eq.  and added vulcanizing agents to them with an internal mixer. The dGTR samples were chosen based on the results of Horikx’s analysis. We investigated the effects of different amounts of vulcanizing agents and paraffin oil. The formulations of rubber mixtures are shown in Table To assess the usability of dGTR in rubbers, we added different amounts of dGTR and GTR (as reference) to NR-based compounds. The recipes of the rubber compounds are shown in Table We prepared a reference sample (NR_REF), a reference sample without paraffin oil (NR_REF_WO), and a reference sample where paraffin oil was replaced with dGTR_MW_100g_2 (NR_REF_WO_dGTR_MW). In the abbreviation of the other samples, the number  means the dGTR content in parts per hundred rubber (phr). In the case of samples ending with "A" or "B", mixing consisted of two steps. In the first step, the dGTR was compounded with vulcanizing agents according to Table 90 (time necessary to reach 90% vulcanization). These time values were obtained from separate rheometer measurements.The rubber ingredients were mixed in a Brabender Plasti-corder internal mixer at 50 °C and 40 rpm. The order of appearance for the components in Tables The curing curves of the rubber compounds were recorded with a MonTech Monsanto R100S rheometer  in isothermal (T = 160 °C) time sweep mode  for 30 min.Hardness was tested according to the ISO 48-4:2018 Shore A method on a Zwick H04.3150.000 hardness tester  on the cured rubber sheets. Ten tests were performed on each compound, followed by the calculation of the average and standard deviation values.The tensile mechanical properties of the compounds were investigated according to the ISO 37:2017 standard on a Zwick Z250 universal testing machine with a 20 kN load cell . Type 1 specimens with a clamping length of 60 mm were loaded at a crosshead speed of 500 mm/min. Tear tests were performed on the same testing machine, and test speed was according to the ISO 34-1:2015 standard (Type C specimen), with a clamping length of 56 mm. Both tests were run at room temperature. The average and standard deviation of the tensile strength, tear strength, and elongation at break values were calculated based on five tests for each compound.Table An hour-long heat treatment (at 140 °C) before devulcanization did not cause a significant change in the sol content. However, when the samples were treated for two hours, the sol fraction increased significantly. The degree of devulcanization followed a similar trend. In other words, the sol content increased significantly, while the cross-link density did not decrease considerably. That indicates the degradation of the polymer chains. Similar conclusions can be drawn for the GTR_H_2 sample.Table 34. Based on Eq. . He identified two different scenarios: random chain scission and scission of the cross-links. In the case of main chain scission, Eq.  shows thmentclass2pt{minim30.34 and it can be determined by Eq.  is the cross-link density, Mn (g/mol) stands for the number-avarege molecular weight of the rubber and The second scenario involves only cross-link cleavage, with no degradation of the polymer main chain. Equation  was formd by Eq. 30. This mentclass2pt{minim39.In this paper, the initial cross-linking index is approximated by Eq. 39.8\docuBased on Eqs.  and 6),,6), the dGTR_MW_50g_2 and dGTR_MW_100g_2 samples had high sol contents, coupled with high crosslink density values. It signified a low degree of devulcanization and suggested the degradation of the polymer chains, as shown in Fig. Table Figures max values increased because of the extra vulcanizing agents added to dGTR but there is no significant effect of the oil content in dGTR mixtures (A and B samples). Traditional vulcanization curves were recorded in the case of all samples containing vulcanizing agents.First, we tried to revulcanize neat dGTR (dGTR_MW_100g_2 sample) without any vulcanizing agents, but curing did not occur  and dGTR_MW_100g_2_0.5A . Even though hot pressing yielded homogeneous, rubber-like sheets, their mechanical properties were quite poor. It is necessary to combine NR with dGTR  with microwaves in a laboratory oven and thermomechanically in an internal mixer with different rotor speeds and temperatures. Then we characterized the devulcanized GTR (dGTR) samples by Soxhlet extraction and swelling tests to determine their soluble content and cross-link density and performed Horikx’s analysis. In the case of microwave-devulcanized samples, cross-link density was considerably reduced while sol content was high, which suggests that the devulcanization process was dominated by the random degradation of polymer chains. Horikx’s analysis showed that these samples suffered severe degradation. In the case of the thermomechanically devulcanized samples at low temperature and rotor speed settings, the main phenomenon was selective cross-link scission. At higher temperatures and rotor speeds, degradation of the main chains occurred along with cross-link cleavage. Based on Horikx’s analysis, four devulcanized GTR samples were chosen and mixed with NR. dGTR content reduced the tensile strength of the samples drastically, but elongation at break did not follow this trend. Curing curves showed that dGTR has a plasticizing effect on rubber mixtures. The tensile strength of samples containing different dGTRs reflects the results of Horikx’s analysis. The samples containing 100 phr of thermomechanically devulcanised GTR had the same tensile strength as the samples with 50 phr of microwave-devulcanized GTR. Two-step mixing  helped recover mechanical properties, especially tear strength.


Most of the already reported lifetimes of molecular dications are in the range of nanoseconds to seconds and metastable states with lifetimes of the order of picoseconds have only been theoretical predicted and an experimental verification is pending. We present a method of measuring subrotational lifetimes of molecular dications formed in three-body sequential breakup of polyatomic molecular precursors. Specifically, we have measured the subrotational lifetime of Singly and multiply charged molecular ions are found in diverse environments and hold relevance for a wide range of research areas like combustion chemistry, accelerator physics, atmospheric sciences, plasma physics, astrophysics etc. Molecular dications are of special significance as they can be generated and studied comparatively easily in laboratory experiments. And they have enabled exploration of new and exciting phenomenon such as hydrogen migration, inter-atomic Coulombic decay, plasmonic excitations, orbital tomography etc. The lifetime of a molecular dication is one of its fundamental characteristics, whose measurement contributes to strengthening  Such studies are also significant in understanding and modeling low density plasmas under terrestrial, planetary and other astrophysical conditions2(and references therein). Several of the simpler molecular dications like that of carbon monoxide  and metastable molecular ions provide insights into a wide variety of physical phenomena and serve as sensitive test cases for theoretical approaches. Specifically, the determination of the lifetime of molecular dications has been a topic of fundamental interest and experimental measurements have been carried out since the time it became technologically feasible19, OCS23, 25, 26 and 27 and different means of initiating the ionisation (leading to dissociation) have been reported. Since the sequential as well as concerted pathways of breakup yield the same set of final three fragment ions, separating the data based on the primary pathway has attracted much attention. It is to be noted that in the sequential mechanism of breakup a metastable molecular intermediate is generated during the first step . And hence, the angle between the momenta of fragments generated from the first and the second step can have any value leading to semicircular arc like distribution as seen in Fig. For the Newton diagram, we have assumed that the lifetime of the intermediate mentclass2pt{minimA Dalitz plot is a representation of the energy correlation between the various fragments. The energy and momentum conservation demands that all events on a Dalitz plot be confined within a circular region. In Fig. 28 plot generated for three-body dissociation processes. (2) the appearance of a semicircular arc like feature in the Newton diagram18 is a signature of the presence of sequential mode of breakup. (3) the probability of a sequential breakup is usually much lower (< 20%) as compared to that of the concerted breakup.The broad observations from the studies on the separation of events based on concerted and sequential breakup mechanisms, over the past two decades can be summarised in the following three points: (1)a large difference between the energy of the terminal fragment ions is most likely associated with the sequential mode of breakup as evidenced also from the Dalitz20,the three-body sequential dissociation of a triply charged molecule is analysed in two different frames of reference, one being the centre-of-mass frame of the triply charged ion (step 1) and the other being the centre-of-mass frame of the doubly charge molecular intermediate (step 2).In the native frames approach28 to select a particular set of events which have a high probability of coming from the sequential mode of breakup of 20 on the selected set. As an additional check on the selected set of events, a Newton diagram is also plotted which confirms the origin of these events as arising from sequential breakup. This allowed us to get a direct estimate of the lifetime  of Inter-University Accelerator Centre, New Delhi. Projectile ions of Figure 18 and 20. The explanation for the appearance of a semicircular arc like feature for these two molecules is the existence of a sequential mechanism for which the populated states of the molecular intermediate have a lifetime much larger than its rotational time period. We propose, that in case of sequential breakup of 31 in its ground state, with a bond angle of 119.5While the Dalitz plot gives a good parametrization for separating events based on sequential or concerted breakup, a Newton plot gives a clearer visual impression of an active sequential process. If we make a Newton diagram for three-body breakup of see Fig.  we see a20 where in the three-body sequential dissociation of a triply charged molecule is analysed in two different frames of reference, one associated with each of the two steps of the dissociation process, see Fig. We now employ the native frames approach23. For the case of For cases where the lifetime (32 which has shown that the presence of an ionic neighbor leads to a shift in the kinetic energy release distribution (KERD) of a covalent molecule towards higher values while keeping the features of the distribution intact. In case of the sequential fragmentation of As is evident from Fig. 31, and energy of the first We have estimated the effect of the presence of By collecting the events with Using a value of 16 ps for the rotational period (In conclusion, we have measured the subrotational lifetime of a molecular dication by combining two powerful techniques, one experimental viz. coincidence momentum imaging and the other, an analysis procedure, the native frames approach. The lifetime of the


Lamprodila  festivafestiva , is a new invasive pest of ornamental Cupressaceae, which has recently expanded its range from the Mediterranean region northwards to central and eastern Europe, and to the Russian Black Sea coast. In this study, we used scanning electron microscopy to examine the morphology, numbers, distribution and possible functions of antennal sensilla in both sexes of L. festiva. In total, we identified 15 different (sub)types of sensilla, of which two are present only in females. We discuss possible functions of all examined sensilla and compare them with those in other Buprestidae or other insects. Our study should serve as background information for subsequent chemical ecology research focused mainly on the olfactory sensory system of this rapidly spreading invasive pest.The jewel-beetles, Buprestidae, comprise some economically important invasive pest species. The Cypress jewel beetle, Lamprodila  festiva festiva , is a serious invasive pest of ornamental Cupressaceae, which has recently expanded its range from the Mediterranean region northwards to central and eastern Europe, and to the Russian Black Sea coast. In this study, we conducted a scanning electron microscopy study of the micromorphology of the male and female antennae of L. festiva to examine the morphology, numbers, distribution, and possible functions of antennal sensilla. Most sensilla are located in the sensory fields within the apical depressions on antennomeres IV–XI. We identified four main types of antennal sensilla in L. festiva: sensilla chaetica , sensilla basiconica (five subtypes), multiporous grooved pegs (two subtypes), and Böhm sensilla. Females have relatively more sensilla chaetica and multiporous grooved pegs, whereas males have more sensilla basiconica. We discuss possible functions of all examined sensilla and compare them with those in other Buprestidae or other insects. Our study should serve as background information for advanced electrophysiological and behavioral experiments to better understand the functions of different sensilla and mechanisms related to semiochemically based pest control strategies.The Cypress jewel beetle,  Global trade networks in combination with other factors, including the climate change, play an important role in the distribution of invasive insects in various parts of the World ,2. BeetlLamprodila  festiva festiva  (Chrysochroinae: Poecilonotini) (hereafter referred only as L. festiva), is a new invasive species native to the Mediterranean region, including southern Europe, which has recently expanded its range to central and eastern Europe, and to the Russian Black Sea coast [Juniperus spp.), cypresses (Cupressus spp.) and sandarac (Tetraclinis articulata (Vahl) Masters, 1892) [Callitris Ventenat, 1808, Chamaecyparis Spach, 1841, Platycladus (Linnaeus) Franco, 1949, Thuja Linnaeus, 1753, and some hybrids. Hence, L. festiva has become a dangerous pest in urban landscapes and nurseries in, e.g., Austria [L. festiva invasion was documented in the Hungarian case. This species was first found in the southern part of the country in 1999 [L. festiva in Hungary [L. festiva, mostly on Platycladus occidentalis (L.) Franco, 1949, was observed in more districts of the capital [The Cypress jewel beetle or Cypress borer, ea coast ,9,10. In Austria , Czech R Austria , Germany Austria , Hungary Austria ,15, Luxe Austria , Romania in 1999 , and for Hungary . Therefo capital . SpecimePest control and management is fundamental for the reduction in the damage caused by invasive pest species, including jewel-beetles. This often includes the development of biological control programs , but alsL. festiva by means of the scanning electron microscopy. Our main goals were to identify the sensillum types, discuss their possible functions, and compare their morphology, number, and distribution with the sensilla of other Buprestidae. The detailed study of the antennal sensillar equipment of L. festiva should serve as background information for subsequent chemical ecology research focused mainly on the olfactory sensory system.In this study, we examined male and female antennal micromorphology of Lamprodila festiva. For each sex, we examined both the left and right antennae of three specimens . All individuals were collected by the second author and bear the following label data: “Hungary, Pest county, Nagymaros, Rigó-hegy, from garden, reared from Platycladus occidentalis (L.) Franco, 1949, 01.–11.06.2019., leg. T. Németh” , a pedicel (antennomere II), and a flagellum composed of nine flagellomeres (antennomeres III–XI)  A–D. In t III–XI) D–F.L. festiva, including the sensilla chaetica (seven subtypes), sensilla basiconica (five subtypes), multiporous grooved pegs (MGP1 and a MGP2 complex), and Böhm sensilla. Their morphological characteristics are summarized in We identified four main types of antennal sensilla in both sexes of L. festiva.The sensilla chaetica are long hairs which are more or less evenly distributed on all antennomeres . They arSensilla C1 are by far the most numerous sensilla chaetica A,B. TheySensilla chaetica C2 are usually curved and saber-shaped D–F. TheySensilla chaetica C3 are somewhat intermediate between sensilla C1 and C2. They are similar in length to sensilla C1 , and usuSensilla chaetica C4 occur only on the scape and pedicel D. They aSensilla chaetica C5 are present only in females. Two of them are on the dorsal face of each of the antennomeres IV–XI, located in the middle of the distal part of antennomere B. They aSensilla chaetica C6 were found only on the outer edge of a single antennomere (VII or VIII) in two females F. They aSensilla chaetica C7 are 15–33 µm long, so they are relatively short compared to the remaining sensilla chaetica . They arL. festiva is larger in males than in females; they form 80.9% of the total antennal sensilla in males and 76.3% in females , whereas the sensory complex formed by a cluster of modified multiporous grooved pegs located on a thick plate is called the “MGP2 complex”. The MGP1 is a cone-shaped sensillum with a bulbous head. It is smooth at the base and has six to eight deep and relatively wide grooves running from about the middle to apex A–G. Theso 2.5 µm A–G. Theso 2.5 µm A–G. Thero 2.5 µm . Their no 2.5 µm . They foo 2.5 µm .The MGP2 sensory complex is a special cluster of several sensilla inserted into a thick circular plate A–G. A siBöhm sensilla are short, smooth, thorn-like bristles with sharp tips A,B. TheyExocrine glandular pores, 0.9 µm in diameter, were found among the sensilla (but never associated with sensilla) at the distal edge of a cuticular scale F,G. TherL. festiva in order to investigate the typology, location, number, and possible functions of antennal sensilla. We identified four main types of antennal sensilla based on morphology, i.e., sensilla chaetica, which were further divided into seven subtypes, sensilla basiconica of five subtypes, multiporous grooved pegs of two subtypes, and Böhm sensilla types and comparisons between related taxa.In this paper, we focused on the antennal micromorphology in both sexes of sensilla . Volkovi species , and con species ,30. Most species . They ar species , apical  species ,30, or s species . Similar species ,38. We dL. festiva have longitudinal furrows and do not possess a terminal pore or wall pores. Contrary to the sensilla in apical depressions, they are well represented on both faces of antennomeres. They are typical aporous sensilla chaetica which are present in all Coleoptera. Several subtypes of sensilla chaetica with similar distribution on antennae were identified in Agrilus mali [Agrilus planipennis [Sensilla chaetica C1–C4 of lus mali , and sennipennis . The cronipennis . These unipennis ,39. Croonipennis ; p. 1105nipennis .Dipseudopsis oliveri Oláh and Johanson, 2010 (Trichoptera) [Agrilus mali [L. festiva could be gustatory receptors. The relatively rare uniporous sensilla chaetica C7 of L. festiva are also gustatory receptors. In other Buprestidae, gustatory sensilla with similar location and numbers include sensilla U1 (various genera and species) [A. mali) [A. planipennis also bear the gustatory function [L. festiva possess more uniporous sensilla chaetica C7 than females, but on the other hand, only females possess sensilla C5 and C6, for which we also hypothesize gustatory function. Various authors suggested that the contact chemical cues are important for mate recognition in Buprestidae, particularly by males, rather than using pheromones at any distance [L. festiva. This is supported by the fact that we failed to find the smooth-walled multiporous sensilla trichodea, which are sensitive to sex pheromones and host plant volatiles [A. mali [L. festiva, this sensillum type was absent in A. planipennis, in which the gustatory sensilla in males outnumber the sensilla of the same function in females [Sensilla C5 and especially C6, which were found exclusively on the female antenna, are identical to sensilla chaetica C4 present on the labial palpus of hoptera) . Their alus mali ; howeverspecies)  or sensiA. mali) . The numfunction . Some bufunction , but othfunction . Males odistance ,41. The olatiles . Sensill[A. mali , but sim females .L. festiva resemble multiporous sensilla basiconica Ba2 of Agrilus mali [Agriotes spp. [L. festiva most probably have an olfactory function. The depressions, with respect to the position of antenna during flight, may enable the concentration of odorous stimuli within the cavity when they are exposed directly to the airflow. Because the probability of an odor molecule striking a sensillum would increase, the efficiency of the odor detection by the sensilla basiconica would increase, too. Sensilla basiconica form 76%  to 81%  of all antennal sensilla, and therefore, the antennal apical depressions in L. festiva have a predominant olfactory function. The sensory fields within the apical depressions in A. planipennis are composed mainly of uniporous chemoreceptors [L. festiva, the depressions have an important contact chemoreceptive function. Most sensilla basiconica in A. planipennis are located on the distal part of flagellomeres, outside the apical depressions, and they most probably form the main olfactory apparatus for detecting host tree volatiles for both sexes of this species [The sensilla basiconica B1 of lus mali  and senstes spp. . All shaeceptors . Therefo species .A. mali [L. festiva or in A. planipennis [Sensilla basiconica Ba3 and Ba4 with a special apical part , which are present in A. mali , have nonipennis .L. festiva are probably identical to some sensilla basiconica in various Coleoptera, e.g., type 3 of Leptura spp. (Cerambycidae) [Callosobruchus rhodesianus  (Chrysomelidae) [Agriotes spp. (Elateridae) [Tetrigus lewisi Candèze, 1873 (Elateridae) [Elater ferrugineus  [Agrilus planipennis [Capnodis tenebrionis [Tribolium castaneum , and noted the presence of longitudinal narrow pores on the bulbous distal peg of these sensilla. The multiporous grooved pegs of beetles are called sensilla coeloconica in Lepidoptera, and are classified as double-walled multiporous sensilla [L. festiva suggests that they perceive odors from host plants for feeding and oviposition.Based on their morphology, the multiporous grooved pegs (MGP) of bycidae) , type 2 melidae) , types 7melidae) , and typteridae) , but alsteridae)  or the gs, 1758) . In Buprs, 1758)  or multis, 1758) . They wenipennis  and Capnebrionis . Seada aebrionis  examinedsensilla . Ultrastsensilla . Based osensilla ,51,52. Wsensilla ,54, the sensilla , Blattodsensilla , and Dipsensilla . The preManduca sexta  [Manduca sexta is formed by several contiguous sensilla styloconica, the number of which depends on the location of the complex on the antenna [L. festiva, varies on antennomeres IV–XI  ,59 =ants, 1763) . The MBSs, 1763) . Accordi . The MBs, 1763) . The sty antenna . Similares IV–XI . The comL. festiva was not studied by Volkovitsh [Saundersina modesta ) and 85  chinganensis , the latter of which is currently a synonym of Lamprodila suyfunensis ). In the latter species, there is probably a single complex on antennomere X and two complexes on antennomere XI . We belAgrilus mali, but not on the base of the pedicel, where these sensilla usually form clusters [L. festiva, Böhm sensilla on the pedicel form a single cluster composed of four sensilla. Yi et al. [A. mali; BB1, which are the usual Böhm sensilla, and BB2 with a bifurcate apex, which were rare and were found only in females. The latter are present also in L. festiva types of sensilla, of which two are present only in females. More than three quarters of all sensilla were olfactory sensilla basiconica, which were housed in the apical depressions on antennomeres IV–XI. They represent the major antennal olfactory system and hence play an important role in the reception of environmental cues like host plant volatiles. We have not found any multiporous sensilla trichodea, which usually serve for detection of sex pheromones [L. festiva, as documented for some other Buprestidae [eromones . Thereforestidae ,41.Our study could also provide taxonomically important antennal morphological characteristics for future comprehensive systematic and phylogenetic research of Buprestidae. We suggest it would be especially interesting to examine the presence of the sensilla MGP2 complex within the jewel-beetle subfamily Chrysochroinae, and, more specifically, in all Poecilonotini and Dicercini, which are hypothesized to be sister-groups . Antenna


The production of pharmaceutical ingredients, intermediates and final products strongly depends on the utilization of water. Water is also required for the purification and preparation of reagents. Each specific application determines the respective water quality. In the European Union, the European Pharmacopeia (Ph. Eur.) contains the official standards that assure quality control of pharmaceutical products during their life cycle. According to this, the production of water for pharmaceutical use is mainly based on multi-stage distillation and membrane processes, especially, reverse osmosis. Membrane distillation (MD) could be an alternative process to these classical methods. It offers advantages in terms of energy demand and a compact apparatus design. In the following study, the preparation of pharmaceutical-grade water from tap water in a one-step process using MD is presented. Special emphasis is placed on the performance of two different module designs and on the selection of optimum process parameters. The forecast of the European pharmaceutical market predicts a 3.9% growth between 2019 and 2024, while the global market is expected to rise by about 4.2% in the same period [Within the current pharmacopoeias, a distinction is made between purified water (PW) and water for injection (WFI) . PW is uPW is produced by distillation, reverse osmosis (RO) in combination with electrodeionisation (EDI), ion exchange or other suitable methods . In contMembrane distillation (MD) may be an alternative process for the generation of pharma-grade water. MD is a thermal separation process based on vapor pressure differences between the feed and the distillate sides of porous, hydrophobic membranes . When drMD is investigated worldwide as a low-cost, energy-saving alternative to conventional separation processes such as distillation and reverse osmosis (RO). MD can be operated at a relatively low feed temperature between 50 °C and 80 °C. Some studies ,8,9 emplFor the operation of MD, it is important that the dry pores are not wetted by the liquid feed, which is directly in contact with the membrane. In contrast to RO, MD is not limited by the osmotic pressure that is generated; furthermore, equipment costs are lower . As MD iMD processes can be categorized into four basic module configurations, which play a fundamental role in separation efficiency and processing costs: direct-contact membrane distillation (DCMD), air-gap membrane distillation (AGMD), sweeping-gas membrane distillation (SGMD), and vacuum membrane distillation (VMD), as shown in There is hardly any information available on the application of MD for the generation of pharma-grade water. A study  reportedThe investigations were carried out using a test plant that was especially designed by Wilhelm Werner GmbH . It alloGenerally, the plant was designed for testing the suitability of MD for the generation of pharma-grade water from tap water. The design criteria considered neither hygienic design nor energetic optimization. Hauser  stated tDeukum GmbH, Germany, provided a plate-and-frame membrane module Type MDX100 with membrane packages for AGMD and VMD, as shown in 2, were stacked in each module, leading to a total membrane area of 0.3 m2. The membrane characteristics are reported in In total, 30 microporous polyethylene membranes type 14P02F from Lydall Performance Materials, each with an effective membrane area of 0.01 mUntreated tap water provided by the city of Leverkusen, Germany, served as feed solution. Tap water served as a cooling agent for the vapor condensation as well.The electrical conductivity is an important quality parameter for the separation efficiency in the MD process. Conductivity was determined with a conductivity meter type JUMO Blackline CR-EC built into the pipeline.M. The resulting value is referred to as flux.The central factor for the efficiency assessment of MD is the transmembrane distillate flow, represented as mass flow or volume flow . To compR, which can be calculated using the conductivity of distillate Dσ and feed Fσ [The degree of desalination is described by the salt retention  feed σF :(1)R=DF=cDY describes the ratio of the generated distillate volume to the feed volume:In batchwise investigations, the yield The investigations included factor variation of influencing parameters to determine optimum operating conditions and long-term experiments. Furthermore, investigations concerning hygienic safety of the process were conducted.Before the examinations were carried out, the statistical variation of the distillate flux was tested at different working points. Statistical variation was so low that each test presented in our paper was carried out only once.F, feed volume flow FF and cooling water volume flow FK, each on three factor levels, were performed. For VMD, also the applied negative pressure was varied. The cooling water temperature in all tests was kept constant at approximately 17.5 °C. The designations 1, 2 and 3 in Full factorial parameter variations of feed temperature TLong-term investigations were conducted with both AGMD and VMD configurations of the test plant. The generated distillate was drained constantly, while the concentrate was fed back to the feed tank. Thus, the concentrate concentration increased over time. For the determination of the total bacteria count in the distillate, the plant was first sterilized for 10 min using a 2 wt% hydrogen peroxide solution. Afterwards, the peroxide solution was rinsed out, and the plant was operated for 24 h at constant operating conditions prior to sampling of the feed solution and distillate. The microbiological investigations took place in an external lab. The total bacteria count of the feed water was measured according to the Germen Trinkwasserverordnung TVO based on DIN EN ISO 6222. The total bacteria count of the distillate was measured according to TVO and Ph. Eur. The examination based on the Ph. Eur. served to check whether the distillate met the requirements for PW or WFI according to Ph. Eur. The decontamination factor DF was calculated using the data of distillate and feed water determined according to TVO.2O2 solution, rinsed and then dried. Spacer and condensation film were visually inspected. A change of the contact angle of the membrane indicates whether the sterilization solution negatively affects the necessary hydrophobicity of the membrane. Thus, a drop test with distilled water was performed on untreated and treated membranes. For this, distilled water was dripped to the membrane sample with a pipette. The contact angle of the drop with the respective membrane sample was determined graphically.The influence of the peroxide solution on spacer, condenser sheet and hydrophobicity of the applied membrane was examined. All materials were inserted for 24 h in a 2 wt% HThe influence of the feed volume flow on the transmembrane distillate flux is depicted in It is apparent that generally, the distillate flux increased with increasing feed volume flow, but the influence of crossflow conditions in the feed chamber on the distillate flux became weaker, as indicated by the slope of the curves, which become flatter with increased feed volume flow.With increasing volume flow of the cooling water, the distillate flux increased for almost all factor level combinations. It is noticeable that for many factor stage combinations, the increase in distillate flow became less evident with the increase of the cooling water volume flow.The influence of the applied vacuum ∆p on the transmembrane distillate flux is shown in F1, FF1, FK1, during which the distillate flux seemed to be unaffected by the applied pressure. The increase of the distillate flux was particularly pronounced across almost all factor levels at the lowest applied pressure of −0.15 bar.Generally, the transmembrane distillate flux increased with increasing negative pressure. An exception was provided by the measuring series TF.For all factor level combinations, the distillate flux increased linearly with increasing feed temperature, as the driving force—vapor pressure—increased.F.The increasing feed volume flow led to an increase in the transmembrane distillate flux, as the crossflow reduced the hydrodynamic boundary layer on the feed side of the membrane.K.For all factor stage combinations, an increase in transmembrane distillate flux with increasing cooling water volume flow can be seen.2h was calculated. This is slightly lower than the value of 4.7 L/m2h achieved with the same parameters during the factor variation investigations.The temperatures of all solutions could be kept constant over time. During the investigation period, 63.1 kg of distillate were generated. This corresponds to a yield of ca. 49%. Based on the amount of distillate, an average distillate flux of 4.4 L/m2 to 806.3 µS/cm. The conductivity of the distillate increased over time and followed the conductivity of the feed. The initially low conductivity in the first hour did not reflect the performance of the membrane. Due to the low flow of both configurations, the conductivity sensor was mounted in a filling pipe. At the start of the long-term investigations, the pipe was filled with air. Contact with air at the beginning of the test runs influenced the sensor until it was fully covered with water. The rise and fall of electrical conductivity can be explained by the start-up performance of the MD plant and remaining solution in the membrane modules. The electrical conductivity of the distillate increased from, initially, 0.9 µS/cm to 2.3 µS/cm. Thus, during the entire test period, the distillate had an electrical conductivity, which corresponded to the quality of PW.The electrical conductivity of the feed increased linearly during the long-term investigation. Within the investigation period of 48 h, the conductivity almost doubled from 410.7 µS/cmThe calculated salt retention R during the AGMD long-term investigation is shown in Basically, the salt retention R was permanently above 99.7%.2h was calculated. This is slightly lower than the value of 3.16 L/m2h achieved with the same parameters during factor variation investigations.The temperatures of all solutions could be kept constant over time. During the investigation period, 9.14 kg of distillate was generated. This corresponds to a yield of ca. 17.8%. Based on the amount of distillate, an average distillate flux of 3.05 L/m2 to 530 µS/cm. The conductivity of the distillate increased over time and followed the conductivity of the feed. The initially low conductivity can be explained by start-up procedures until the pipe that contained the sensor was filled with liquid. The electrical conductivity of the distillate increased shortly within the first hour, from, initially, 0.7 µS/cm to 1.6 µS/cm. Then, the conductivity decreased again, reached a value of 0.9 µS/cm and remained constant until the end of the investigation. Thus, during the entire test period, the distillate had an electrical conductivity, which corresponded to the quality of PW and WFI.The electrical conductivity of the feed increased linearly during the long-term investigation. Within the investigation period of 10 h, the conductivity increased from 435 µS/cmThe salt retention R of the VMD as a function of the time is depicted in The initially high salt rejection in the beginning of the long-term investigation is attributed to the insufficient construction details of the applied membrane plant, as described before. Salt retention was permanently above 99.6%. Decrease and increase in salt retention within the first five hours is justified by the course of the distillate conductivity, .The results of the microbiological studies are presented in To determine the decontamination factor with regard to the total bacteria count, the respective results depicted in About 4% of the total bacteria in the feed could be found in the distillate. Therefore, the MD provided a rejection of the microbiological impurities of approximately 96%. It is noticeable that the decontamination factor for the incubation at 22 °C is significantly lower than that for the incubation at 36 °C.The total bacteria count in the distillate met the requirements of PW but did not meet the requirements of WFI.The drop test prior to and after the insertion of the membrane material showed that sterilization with an aqueous 2% H2O2 solution did not negatively affect the hydrophobicity of the membrane, as the measured contact angle was >90% in both conditions. The spacer and film material were also suitable for sterilization with the aforementioned solution.F, feed volume flow FF and cooling water flow FK on the transmembrane distillate flux FD during AGMD.F is the decisive factor to increase the transmembrane distillate flow. The increase in the feed volume flow led to a reduction in the boundary layer resistance. However, this effect was limited. The effect of the cooling water flow FK on the distillate flux was negligible.It is obvious that the feed temperature TF, feed volume flow FF, cooling water flow FK and applied negative pressure on the transmembrane distillate flux FD during VMD.F had the greatest influence on the transmembrane distillate flux during VMD, followed by the feed volume flow FF and the cooling water volume flow FK. The applied negative pressure ∆p had the smallest effect on the distillate volume flow. However, ∆p had to be kept above −0.2 bar, as the feed tank design did not allow lower values. Accordingly, the effect of negative pressure on the performance of VMD could not be predicted.Similar to what observed for AGMD, the feed temperature TThe long-term investigations showed that both AGMD and VMD were able to produce distillates with an electrical conductivity within the limiting values of PW.Noticeable is the dependence of the electrical conductivity of the distillate on the conductivity of the feed during AGMD. It is assumed that an intrusion of the feed solution into the distillate cycle occurred. The intrusion of the feed was caused either by minimal defects of the sealings or by a too high pressure on the feed side of the membranes that caused mass transfer through the pores of the actually hydrophobic membranes (exceedance of the liquid entry pressure LEP). In addition, the investigations showed that a certain maximum concentration of the concentrate limited the process, as the quality of the distillate depended on it. The achievable yield of AGMD thus seems limited.The long-term investigation of the VMD did not show a comparable behavior. The conductivity of the distillate did not increase when the concentration of the feed rose. However, VMD investigations were significantly shorter compared to AGMD ones, so the concentrate concentration did not reach a hypothetical critical value.The achievable distillate fluxes were smaller compared to the respective fluxes measured during parameter variation. It is assumed that the reason is vapor pressure reduction due to the increasing salt concentration of the concentrate. The driving force of membrane distillation during the long-term investigations was reduced accordingly and led to the decrease of the distillate flux.The total bacteria count in the distillate met the requirements of PW but not those of WFI. The measured bacteria counts were 30–40 times higher than the limit value of WFI and 250–330 times below the limit value of PW. However, neither the test plant nor the module fulfilled the demands of hygienic design, as the detachable connections in the product and distillate-contacting area were realized with screw connections.The investigations carried out showed that single-stage MD is suitable for the production of pharmaceutical-grade water. The generated distillate reached the claims of Ph. Eur. for PW regarding the electric conductivity and the total bacteria count.The feed temperature was the decisive factor for the performance of both AGMD and VMD configurations. All other factors played a minor role. VMD showed no significant increase in transmembrane distillate flow with an applied vacuum. The main reason for this behavior is the limited negative pressure on the distillate side that could be achieved in the test facility. Future studies of VMD should therefore be carried out below −0.2 bar.Future studies must also provide information on whether MD is comparable to distillation and membrane-assisted processes in terms of yield and specific energy demands. The decisive factor for this is the decoupling of the quality of the distillate from that of the feed.In addition to the necessary technical investigations, the approval of the legislator is crucial for the establishment of MD as a possible alternative to distillation and cold production by RO in a strictly regulated market. Then, the decision of pharmaceutical manufacturers to use MD will depend on the strict adherence to operational safety. This also includes the approval of FDA or other institutions for any kind of material used in the plant.Further applications of membrane distillation in the field of ultrapure water generation seem to be promising for the treatment of water for hydrogen production. The electrolysis used for water splitting requires a fully de-salted and softened feed water. Hygienic requirements similar to those of the pharmaceutical industry do not exist. Excess heat from the electrolysis plant can be used to heat the feed water.


The physics side of organogelation is broached through three main aspects, thermodynamics (formation and melting), structure (morphology and molecular organization), and rheology. A definition of a gel is first discussed so as to delimit the field of investigation; namely, systems constituted of fibril-like entities. It is again highlighted that gel formation occurs through first-order transitions, chiefly by homogeneous nucleation. A deeper knowledge of the system is thus achieved by mapping out the temperature–concentration phase diagram. Some experimental diagrams are shown, while diagrams likely to pertain to these systems are presented. The molecular arrangement is basically crystallization that occurs in a preferred direction, hence the formation of fibrils. The effects of the solvent type, the quenching process of the solution are discussed with respect to the morphology and the crystal structure. Finally, the rheological properties are tackled. Notions of critical gelation concentration and percolation are debated. The interest of mapping out the temperature–concentration phase diagram is emphasized, particularly for understanding the variation of the gel modulus with temperature. Organogelation is a relatively-new topic that has emerged these past 20 years ,2,3,4,5.The first section will be devoted to defining what can be termed organogelation and what are the objects associated with this concept. The thermodynamics of organogel formation is an important step in understanding these systems, particularly through the mapping out of the temperature-composition phase diagram. The different types of morphologies and molecular structure will be then examined. A final section will be devoted to their rheological properties.The colloidal condition, the gel, is one which is easier to recognize than to define” ,36trans-llations a. Indeedn = 3.3 nm corresponds to the length of the BHPB-10 molecules.Using larger n does not improve the fit. The thickness of the nanotubes, eq = 1.92 nm−1 corresponding to d = 3.27 nm from Bragg’s law. This value, related to the organization within the nanotube, turns out to be close to the length of the BHPB-10 molecule. This maximum can be fitted with a simple Gaussian function:q = 0.99.One observes an additional, conspicuous maximum in the X-ray pattern, which peaks at The maximum seen in SAXS is absent in SANS a. It hascis-decahydronaphthalene differs significantly from that obtained in trans-decahydronaphthalene  = 0.63 with ξ = 10 nm against Δq(20 °C) = 0.19 with ξ = 33 nm. Clearly, the deeper the quench, the thinner the fibrils since this corresponds to the Z-direction  of the type 1/2 is used to mimic the liquidus line (inset of orgC~ a−1exp(T2). If one further assumes that the elastic modulus varies as:G′ vs. T shown in An example is shown in inset of a. The inThis short paper advocates the extensive study of the physical properties of organogel in order to throw some light on the gel formation mechanism, and ultimately to be able to estimate the probability for a given molecule to produce a gel. Several attempts in this aim have been already put forward ,55.chimeras” molecules, that is to be an assembly of parts with differing interaction properties such as hydrogen bonding, Van der Waals interaction or/and π-π interaction. The presence of long aliphatic arms is often a prerequisite [Sticking to the definition developed above, namely, a gel must consist of highly elongated, crystalline objects, implies to design systems that are to display a crystallization behaviour that privileges crystal growth in one direction. As suggested by Guenet the candidates must be “equisite . The OPVequisite   as these gelators usually possess molecular weight larger than usual organic molecules, such as solvents, but much smaller molecular weights than macromolecules. Yet the term “low-molecular-weight “is confusing, after all solvents are also low-molecular weight molecules! It is felt that the term “These prerequisites are chiefly indicative as the gelation behavior can be totally different in a series of molecules. For instance, the capability of BHPB molecules to produce nanotubes depends strongly upon the length of the aliphatic arms , which m


Core-shell nanofibers have great potential for bio-medical applications such as wound healing dressings where multiple drugs and growth factors are expected to be delivered at different healing phases. Compared to monoaxial nanofibers, core-shell nanofibers can control the drug release profile easier, providing sustainable and effective drugs and growth factors for wound healing. However, it is challenging to produce core-shell structured nanofibers with a high production rate at low energy consumption. Co-axial centrifugal spinning is an alternative method to address the above limitations to produce core-shell nanofibers effectively. In this study, a co-axial centrifugal spinning device was designed and assembled to produce core-shell nanofibers for controlling the release rate of ibuprofen and hEGF in inflammation and proliferation phases during the wound healing process. Core-shell structured nanofibers were confirmed by TEM. This work demonstrated that the co-axial centrifugal spinning is a high productivity process that can produce materials with a 3D environment mimicking natural tissue scaffold, and the specific drug can be loaded into different layers to control the drug release rate to improve the drug efficiency and promote wound healing. Polymeric nanofiber materials have been extensively studied for various bio-medical applications including tissue engineering ,2, woundCentrifugal spinning is a technology that uses high rotation speed to fabricate three-dimensional (3D) structured nanofibers ,19,20. IWound healing is a complex and multifactorial process, often referred to as the cascade of healing including four phases: hemostasis, inflammation, proliferation, and remodeling . These pCell growth factors including epidermal growth factors (EGF), vascular endothelial growth factor (VEGF), transforming growth factor-β (TGF-β), and platelet-derived growth factor (PDGF) play a significant role in connecting cells and ECM to improve functional restoration of tissues at the proliferation phase . For exaIn this paper, a novel biomimetic system was designed via co-axial centrifugal spinning technology to produce core-shell nanofibers for effective drug delivery and wound healing. Formation of core-shell structured nanofibers via self-assembled co-axial centrifugal spinning was investigated by changing various parameters. Two model drugs used as anti-inflammatory drug (ibuprofen) and human epidermal growth factors (hEGF) were loaded into the shell layer and core layer, respectively, to improve the multi-functionality of core-shell nanofibers for wound healing. The advantages of multi-functional core-shell nanofibers over monoaxial nanofibers and a commercial wound dressing (AquacelAg) were evaluated via drug release profiling, antibacterial assessment, and the cell viability assay. This work demonstrated that the drug release rate in core-shell nanofibers can be better controlled and different drugs can be delivered at different phases of wound healing. In addition, biodegradable water-soluble nanofibers with drugs or growth factors might be more suitable for wound healing compared with AquacelAg (hydrophilic fibrous wound dressing) as the secondary damage to the wound caused by any residual dressing during dressing change can be avoided.Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), and Staphylococcus aureus (S. aureus) were purchased from the Guangdong Microbial Culture Center . A human skin fibroblast cell line  was purchased from iCell Bioscience Inc. . AquacelAg was purchased from ConvaTec Inc. . All materials were used as received without further modifications.Carboxylated chitosan , polyethylene oxide , and ibuprofen were purchased from Aladdin . Human epidermal growth factor (hEGF) was purchased from Sigma . w/v%; PEO powder was dissolved into DI water at concentrations of 6 w/v% and 7 w/v%; CCS (14 w/v%) and PEO (7 w/v%) solutions were then mixed to prepare CCS/PEO composite solutions at 1:1 CCS/PEO and 2:1 CCS/PEO. All of the above solutions were stirred for 8 h at room temperature. Various parameters were changed to produce nanofibers via co-axial centrifugal spinning including viscosity, rotational speed, nozzle diameter, and solution flow ratio between core and shell layers. The collection distance was 30 cm and the temperature was 25 °C.CCS powder was dissolved into deionized (DI) water at a concentration of 14 To prepare monoaxial nanofibers with two model drugs, 10 mg/mL ibuprofen and 1 μg/mL hEGF were mixed into a 1:1 CCS/PEO solution, followed by stirring for 15 min in an ice bath. The operational conditions of the centrifugal spinning system were: rotational speed of 4500 rpm, collection distance of 30 cm, and temperature of 25 °C. cD is the drug density of the core layer; and sD is the drug density of the shell layer in a core-shell nanofiber. The core layer nozzle was 30 G (inner diameter: 0.13 mm and outer diameter: 0.31 mm); the shell layer nozzle was 22 G with 0.41 mm inner nozzle diameter and 0.7 mm outer diameter, therefore, there was a channel with a 0.1 mm for the shell layer solution. After calculation, 5 μg/mL hEGF was mixed into 7 w/v% PEO solution as the core layer and 12.5 mg/mL ibuprofen was mixed into the 1:1 CCS/PEO solution as the shell layer, then the core layer and shell layer solutions were stirred for 15 min in an ice bath, respectively. The other operational conditions were the same as those for the production of monoaxial nanofibers.To prepare core-shell nanofibers with drugs, drug loading in each unit length for each drug in the core-shell nanofibers should be the same as those in monoaxial nanofibers. Therefore, the drug density relationship between core-shell nanofibers and monoaxial nanofibers should be followed,The morphology of nanofibers were studied with scanning electron microscopy . Prior to testing, the obtained nanofibers were coated with Au by a sputter coater , and the diameters of the fibers were measured with ImageJ image processing software. For each type of fiber specimen, three different SEM images were taken and 100 counts of fibers were measured to calculate the mean fiber diameters and the fiber diameter distribution. Core-shell structure of the nanofibers was confirmed by transmission electron microscopy . For each sample, fibers were deposited onto a carbon-coated copper grid and analyzed by TEM with 200 kV.w/v%), CCS (14 w/v%), 1:1 CCS/PEO, and 2:1 CCS/PEO solutions were measured by an AR-2000ex rheometer  with various ratios by following the experimental procedures reported previously [The viscosities of PEO . A total of 15 μL of deionized water was placed on the surface of the mats and the contact angle was measured after 2 s. The test was measured at room temperature.−1. In the TGA measurement, each sample was conducted from 30 °C to 600 °C with a heating rate of 10 °C min−1.The thermal properties of fibers were tested by differential scanning calorimetric  and thermogravimetric analysis . Around 5 mg of polymer fibers were used for each sample. In the DSC test, the temperature increased from 30 °C to 250 °C with a heating rate of 10 °C minMechanical tests were performed for all samples via an Instron 5943  with a 50 N load cell. Each sample was twisted into a yarn with a 0.5 mm diameter and cut into 10 mm lengths. The extension rate of sample was 2 mm per minute, and the Young’s modulus and failure work were calculated from the stress–strain curve. Each type of sample was tested three times. The test was measured at room temperature.−1 and a resolution of 1 cm−1 with 64 scans.Fourier transform infrared spectroscopy  was used to study the chemical characteristics. All samples were tested at wavelengths in the range of 4500–400 cmThe release tests of ibuprofen loaded in the shell layer of the core-shell structured nanofibers and monoaxial nanofibers were performed by the dialysis bag (3500 Da) method with 0.1 M PBS solution (pH 7.4) as the receptor medium. The cumulative release profile of hEGF was established by measuring the amount of hEGF in the collected PBS medium by the hEGF ELIAS Kit by following the manufacturer’s instruction. The release tests of hEGF loaded in the core layer of the core-shell structured nanofibers and monoaxial nanofibers were performed by the dialysis bag (14 kDa) method with 0.1 M PBS solution (pH 7.4) as the receptor medium. PBS was used to mimic the wound environment and maintain wet conditions during the experiments. For each experiment, 10 mg of nanofiber scaffolds was loaded into a dialysis bag, then put into 10 mL PBS solution at 37 °C constant temperature. The samples were placed on an orbital shaker at 200 rpm. At specific intervals , 1 mL released medium was collected and stored at −20 °C for a later test, then replaced with 1 mL fresh PBS solution. The release profile was analyzed via ELISA at 265 nm for ibuprofen and 450 nm for hEGF, respectively. Each sample was tested three times.2/mL, then incubated in an aseptic incubator for 24 h at 37 °C. Using HSF in a 96-well plate, a 100 μL HSF cell suspension (0.5 × 104 count) was plated into every well. After 24 h incubation in a 5% CO2 incubator, HSF was seeded into the extraction solution and incubated for 12 h, 24 h, and 48 h. Then, the wells were washed with PBS twice, and 200 μL MTT (5 mg/mL) was dropped into the wells and incubated for 24 h. After incubation, 150 μL DMSO was dropped into each well and put the well-plate on a shaker with low shaking for 10 min. Optical density of the viable cells was read by ELISA at an OD of 570 nm. The cell viability was calculated by:Cell viability of HSF on different nanofiber mats and AquacelAg were operated according to ISO standard 10993-12 2007 via the MTT assay. Before the experiments, all samples  and AquacelAg (positive control)) were vacuum dried and UV sterilized for 30 min. To prepare the extraction solution, each specimen was placed into 10% DMEM solution with the ratio of specimen surface area and solution volume as 1.25 cmEscherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), and Staphylococcus aureus (S. aureus) were used to assess the antibacterial activities of nanofibrous samples and AquacelAg. Before the experiments, all samples were vacuum dried and UV sterilized for 30 min. All of the prepared bacterial strains were incubated in Luria-Bertani medium with an orbital shaker at 37 °C/220 rpm, until the OD value at 600 nm reached 0.6 . Each bacterial suspension was diluted 100 times. Then, 15 mL of the diluted bacterial suspension was spread onto a Petri dish (9 cm diameter). The disk-shaped (1 cm diameter) nanofibrous mats and AquacelAg mats were placed onto the corresponding bacterial Petri dish and incubated for 24 h at 37 °C. Then, the inhibition zone was photographed and measured. The experiments were repeated three times and operated in an aseptic environment. To evaluate the antibacterial activities of the nanofibrous scaffolds via centrifugal spinning, four different scaffolds were used including core-shell nanofibers loaded with hEGF in the core layer and ibuprofen in the shell layer (named as core-shell nanofiber with drugs), and monoaxial nanofibers loaded with hEGF and ibuprofen . AquacelAg and core-shell nanofibers without drugs were chosen as the positive control and the negative control, respectively. p) < 0.05 was considered as statistically significant.Statistical analysis of all data was calculated as the mean + standard deviation (SD), and performed using one-way ANOVA. A probability value  and the average diameter of Sample I was higher than the average diameter of other samples. The viscosity of polymer solutions for both the core and shell layers will determine whether a core-shell fiber can be formed. The polymer solution is a non-Newtonian liquid and the fiber formation can be described by dimensionless numbers . The difw/v% PEO and 1:1 CCS/PEO (Sample I condition), the curvature radiuses of the core layer jet and shell layer jet could be the same, so the two layers still remain at the co-axial jet at the jet-extension stage. Therefore, the core-shell structured jet remained at the solvent evaporation stage and the core-shell structured nanofiber was formed after core-shell jet solidification. The core-shell structured nanofiber could not be characterized by TEM in three other samples. This might be because the In addition, the dynamic viscosities of various solutions in the core and shell layers were varied by changing the concentration of PEO or the ratio of CCS/PEO . Besides numbers :(4)Re=ρvcosities . TherefoDSC curves of the four samples via co-axial centrifugal spinning were similar c. There On the other hand, the endothermic peaks of sample I were higher than the others, which indicated that the covalent bonds between the two phases in sample I were more than the other samples. This might be attributed to more phases of the block copolymer existing in sample I than in the other samples, which further explains that core-shell structures formed in sample I compared with the other samples. The mechanical properties of samples G–J in Mechanical properties of the nanofibers are strongly influenced by many factors including the chemical structure of polymers and the physical properties of fibers . As a previous study demonstrated that a higher CCS component led to better mechanical properties , the mec−1 can be attributed to molecular bending vibrations [−1 corresponded to the C–O stretching [−1 was due to the vibration of the ether group [−1 in CCS can be attributed to the C–O stretching vibrations of the pyranose ring [−1. Similar result were also demonstrated in the study by Lin et al. [−1 can be attributed to the C–O–C stretching vibrations [−1 corresponded to O–H deformation mode [−1 were attributed to amide groups [−1 was due to the CH2 stretching [−1 was detected due to N–H and O–H stretching of the polysaccharide molecules [The functional groups in the produced nanofibers (samples G–J) via co-axial centrifugal spinning as well as the pure PEO and pure CCS were characterized by FTIR . The finbrations . The pearetching  and the er group . The peaose ring . These tn et al. . The peabrations ,47. The ion mode . Two peae groups . The pearetching . A broadolecules . All chaThe contact angle of the nanofibers is also influenced by the chemical composition and fiber morphology. The CCS percentage in samples G and H was higher than that in samples I and J, therefore, samples I and J should be more hydrophilic than samples G and H ,68. HoweThe drug release mechanisms in nanofibers mainly depend on drug diffusion, polymer nanofiber biodegradation, and nanofiber erosion . The hEGThe ibuprofen release profiles in the shell layer of core-shell nanofibers and monoaxial nanofibers are shown in The viability of HSF cells on the produced core-shell nanofiber mat with hEGF, monoaxial nanofiber mat with hEGF, and core-shell nanofiber mat without hEGF (negative control) as well as the commercial wound dressing, AquacelAg (positive control), were investigated by the MTT assay, as shown in Notably, the cell viability in the nanofiber mats with hEGF tended to fluctuate from time to time, while the cell viability in the positive and negative control always decreased. At 12 h, the cell in the core-shell nanofiber mat with hEGF and the monoaxial nanofiber mat with hEGF had a similar viability of 91% and 92%, respectively. At 24 h, the cell viability in core-shell nanofiber with hEGF decreased to 80%, but the value at monoaxial nanofibers with hEGF increased to 94%. This might be because the release rate of hEGF in the core layer of the core-shell nanofibers was slower than that in the monoaxial nanofibers, and the reacted hEGF in the medium with monoaxial nanofibers was larger than that in the medium with core-shell nanofibers at the period. Therefore, the cell viability in the monoaxial nanofiber was better than in the core-shell nanofiber. However, the cell viability in the core-shell nanofiber with hEGF increased to 86% and the cell viability in the monoaxial nanofiber with hEGF decreased to 86% at 48 h. This might be because the hEGF in the core layer of the core-shell nanofiber sufficiently released and reacted after 24 h, while the hEGF in the monoaxial nanofiber burst released at the beginning of a few hours. Therefore, HSF cells in the core-shell nanofiber were more active as hEGF was stably released, and the cell viability in the monoaxial nanofiber decreased after hEGF burst release at the initial time. The final cell viability of the core-shell nanofiber and monoaxial nanofiber was the same.Chitosan is an attractive biodegradable and biocompatible polymer for wound healing materials due to its antibacterial and antifungal properties . HoweverE. coli, S. aureus and P. aeruginosa) after 24 h of incubation with nanofiber mats and AquacelAg are shown in E. coli with only a 3.6 mm diameter of inhibition zone, and almost no effect on S. aureus and P. aeruginosa due to the zone still being occupied by some bacteria (light color zone). This indicates that the CCS composite mat had weak antibacterial properties without ibuprofen.The growth inhibition zones of bacteria (In addition, the core-shell nanofiber with drugs and monoaxial nanofiber with drugs had the similar antibacterial properties to AquacelAg because both CCS composite mats were loaded with ibuprofen, which is an effective drug for the inhibition of bacteria . After 2In this study, a co-axial centrifugal spinning device was developed to fabricate core-shell nanofibers. After investigation, core-shell structural nanofibers via co-axial centrifugal spinning could be stably produced, and the mechanical property of the core-shell nanofiber was better than the monoaxial nanofiber. Besides, in vitro experiments demonstrated the advantages of the produced core-shell nanofiber for potential wound healing application. Multiple drugs could be loaded into the different layers of the core-shell nanofiber to control the drug release rate in different phases for specific drug delivery and improve the drug efficiency during the wound healing process. The production rate of co-axial centrifugal spinning is much higher than traditional co-axial electrospinning, showing the potential of commercialization.


Nanofibers have emerged as a potential novel platform due to their physicochemical properties for healthcare applications. Nanofibers’ advantages rely on their high specific surface-area-to-volume and highly porous mesh. Their peculiar assembly allows cell accommodation, nutrient infiltration, gas exchange, waste excretion, high drug release rate, and stable structure. This review provided comprehensive information on the design and development of natural-based polymer nanofibers with the incorporation of herbal medicines for the treatment of common diseases and their in vivo studies. Natural and synthetic polymers have been widely used for the fabrication of nanofibers capable of mimicking extracellular matrix structure. Among them, natural polymers are preferred because of their biocompatibility, biodegradability, and similarity with extracellular matrix proteins. Herbal bioactive compounds from natural extracts have raised special interest due to their prominent beneficial properties in healthcare. Nanofiber properties allow these systems to serve as bioactive compound carriers to generate functional matrices with antimicrobial, anti-inflammatory, antioxidant, antiseptic, anti-viral, and other properties which have been studied in vitro and in vivo, mostly to prove their wound healing capacity and anti-inflammation properties. Nanotechnology has enabled the development of new technology to generate functional nanomaterials capable of carrying drugs in the form of dendrimers, liposomes, nanoshells, emulsions, nanotubes, and nanofibers for the treatment of certain diseases. Among them, nanofibers have offered a great potential application as a drug carrier system of synthetic or natural compounds that have poor bioavailability . They arThe use of isolated bioactive compounds, obtained from medicinal plants, known as synthetic medicinal plants, represents high cost and has been shown to induce negative side effects in humans. These negative effects have been attributed to the purification process that can produce toxic byproducts ,5. In thThis review will provide and discuss the current strategies for the design and development of natural-based polymer nanofibers with the incorporation of herbal extracts for the treatment of common diseases and their in vivo studies. Specifically, this review will show the therapeutic effect of natural bioactive compounds in active nanofibers summarizing their usage in the healthcare field as functional matrices in wound dressings, tissue engineering, and drug delivery systems. Finally, some in vivo studies were added in order to compare the wound healing potential of these nanofibers to the commercially available products. The novelty of this study is that it provides a panoramic and integrated view of the use of technology, especially nanotechnology, and ancestral medicine for the development of delivery systems with health applications that simulate different benefits through a combination unique among various active components present in each of the extracts.TM), solution blow spinning, and carbon dioxide (CO2) laser supersonic drawing. In this section, their main characteristics and advantages will be discussed.Several techniques for the production of nanofibers have been developed in order to reduce production time, to include more and better materials, and to lower costs, among other characteristics ,10,11,12Among the current strategies to produce nanofibers, electrospinning (e-spinning) has been the most widely used technique over the last years. Electrospinning has offered several advantages such as easy control for fiber diameter, morphology, surface characteristics, mesh porosity, and the possibility of getting fibers with diameters ranging from tens of nanometers to several micrometers ,14. ElecThe physical characteristics of the nanofibers depends mainly on three factors: (i) the polymer solution parameters , (ii) technical parameters , and (iii) environmental conditions (temperature and humidity) . Thus, iWith the development of new materials and the evolution of the technology, it will be possible to develop three-dimensional systems as complex and versatile as required using the e-spinning technique. It will be possible to generate scaffolds as substitutes for human tissues, systems for the controlled and sustained delivery of drugs, medical devices, and novel cosmetic products that could even replace some surgeries. Despite its wide applications, the electrospinning technique presents diverse limitations such as low yield, use of specialized equipment, high electrical potential, electrically conductive targets, and high costs . HoweverTM has emerged as a novel strategy for the fabrication of nanofibers; this technique is considered a non-electrical nanofiber spinning because it uses centrifugal forces to form nanofibers (average diameter ranging between 130–300 nm) instead of high voltage conditions ..136].S. aureus, and demonstrated by in vivo assays its wound closure potential by promoting a wound contraction of 96.3 ± 4% and 100%. Another study fabricated Lawsonia inermis extract coupled with gelatin-oxidized starch (OST). Oxidized starch has the ability to easily react with the amino groups of gelatin and crosslinked gelatin. This matrix enhances the attachment and proliferation of fibroblast cells, collagen secretion, and demonstrated antibacterial activity. Gelatin-OST-extract nanofibers were assessed in vivo on a second-degree partial burn wound, demonstrating a thinner inflammatory zone as well as less inflammatory response and macrophage amount compared with those control fibers [Adeli-Sardou et al.  analyzedl fibers .Garcinia mangostana extracts have been incorporated into a chitosan-ethylenediaminetetraacetic acid-polyvinyl alcohol nanofiber (CS-EDTA-PVA) showing antibacterial against S. aureus and E. coli strains and antioxidant activity. They also showed cell viability in NHF above 90% using GM extract concentrations between 1 and 5 mg/mL and accelerated the wound healing process compared with traditional and commercial gauze dressing [Chitosan-based nanofibers have also been assessed to design novel wound dressing systems incorporated with bioactive compounds. dressing .E. coli, P. aeruginosa, S. aureus and methicillin-resistant Staphylococcus aureus (MRSA)). Silk fibroin-MH nanofibers also showed an increase in wound healing by stimulating the release of cytokines and inducing an immune response against skin infection. Ranjbar-Mohammadi et al. [S. aureus and E. coli.Yang et al.  worked wi et al.  reportedi et al.  also repIndigofera aspalathoides, Azadirachta indica, Memecylon edule (ME), and Myristica andamanica with a biodegradable polymer, PCL by electrospinning. The authors describe a positive proliferation of human dermal fibroblast (HDF) and high cell viability in presence of extract-PCL nanofiber [Another work showed the fabrication of soy protein hydrolysate (SPH)/cellulose acetate (CA) nanofibers by rotary jet spinning to enhance skin regeneration. Soy protein can mimic the fibrous dermal ECM microenvironment; due to this similarity, soy peptides can promote cell adhesion, proliferation, and migration. In addition, since it carries phytoestrogens, they can bind to specific estrogen receptors which have positive effects on ER-mediated processes to accelerate the healing process. Coupled with this, soy peptides are reported to have antibacterial, anti-inflammatory, and antioxidant properties. SPH/CA nanofibers showed low cytotoxicity in human dermal fibroblasts (HNDF) and an increased integrin β1 expression indicating that the nanofiber can activate the expression of integrin β1 and therefore accelerate cell migration and start the production and maturation of ECM proteins. In vivo assays in mice demonstrate accelerated wound closure and skin regeneration . Yet anoanofiber .Commonly, when there is a tissue injury or organ failure, organ transplantation of the organ or tissue is the first clinical option to restore the functionality of the affected area. Nevertheless, this method leads to certain biological limitations such as the allorecognition, graft rejection, and administration of immunosuppressive agents, among others. As a solution, tissue engineering has aroused special attention as an “interdisciplinary field that applies the principles of engineering and life sciences toward the development of biological substitutes that restore, maintain, or improve tissue function” . Tissue ECM proteins provide structural support and integrity to tissues, promote cell adhesion, and regulate cellular mechanisms. Differences in ECM structure and organization may be attributable, in part, to variation in size and hemodynamic burden of its different components. Thus, nanofibers are a suitable option to resemble native ECM because they are at the same scale as ECM proteins. Furthermore, its properties such as mechanical stability, high specific surface area, mesh porosity, biocompatibility, and biodegradability allow its usage as a scaffold . NaturalTrigonella foenum graecum possesses antioxidant properties which allow to reduce wound damage by reducing reactive oxygen species during inflammation, while silk fibroin promotes collagen synthesis and proliferation of epithelial cells. Results show a cumulative release of fenugreek of 73 ± 0.9%. Fenugreek presence in silk fibroin nanofiber confirms its antioxidant property, by obtaining 49.3% of antioxidant property through 2,2-diphenyl-1-picrilhidrazil (DPPH) assays. Cell viability assays with albino 3T6 fibroblast showed 100% viability while cellular behavior analysis showed an increase in cell proliferation and adhesion to the scaffolds. Moreover, fenugreek/silk fibroin nanofibers obtain higher wound closure rate (95.8%) compared with gauze and silk fibroin nanofiber (78.9% and 93.7%).Selvaraj and Fathima  reportedAnother study fabricated curcumin/zein nanofibers by electrospinning nanofibers optimizing zein nanofibers with fluorescence to observe curcumin incorporation. The addition of curcumin potentiates formation of granulation tissue, ECM biosynthesis, cell proliferation, and promotes antioxidant properties. Results showed an enhanced attachment and proliferation of L929 fibroblast cells, suggesting the cytocompatibility of the nanofibers. Furthermore, antioxidant activity was dependent on curcumin concentration in nanofibers, obtaining a 91.2% inhibition using the highest concentration (10 wt%) . Aloe vera (AV) gel has also been incorporated into PLLA/collagen nanofibrous scaffold by electrospun. The authors described the use of Aloe vera gel, since it can accelerate the wound heling process due to the presence of glycoproteins, saccharides, vitamins, and antioxidants. PLLA/collagen/AV scaffolds promote a favorable environment for cell survival, proliferation, and adhesion of L929 fibroblasts [Allium sativum L., Mentha spicata L., and Agaricus bisporus for their use as skin and bone scaffolds.roblasts . Recentlroblasts  describeIn recent years, nanotechnology has enabled the development of new drug delivery systems which contain a specific amount of a bioactive compound and control the rate and time of release at a specific site of the organism. Nanofibers have roused special interest as a drug carrier system for being a matrix with high surface area and mesh porosity. According to Thakkar and Mirsa , the druOther parameters are those related to polymer characteristics such as composition, crystallinity, and molecular weight. For example, hydrophilic and amphiphilic copolymers can increase compound loading and decrease probabilities of burst release, while polymers with amorphous regions can have faster release rates unlike those with crystalline regions, in which water uptake is lower. Finally, bioactive compound loading parameters, such as loading amount, molecular weight, physical state, solubility, and compound-polymer interaction, can also influence the release performance of the nanofibers .Depending on the final drug release characteristics, six techniques have been reported for the attachment of the desired drug with a nanofiber: (1) co-spinning, (2) side-by-side-spinning, (3) multi jet, (4) coaxial, (5) emulsion spinning, and (6) surface immobilization. Among them, co-spinning is the most used since the drug and polymer can be blended before proceeding with the nanofiber method. Nevertheless, some limitations are encountered by this loading method. First, the bioactive compounds may be compromised using high voltages conditions or method temperatures. Second, incorporation of both bioactive compounds and polymers may be tough if they are not soluble in the same solvent. To overcome these limitations, loading methods such as side-by-side and multi jet can be used, since polymer and bioactive compounds solutions can be added separately. In addition, core/shell structure nanofibers can be fabricated using coaxial and emulsion spinning, while surface immobilization involves covalent coupling of bioactive compounds to the surface of the nanofiber ,151.The incorporation of natural extracts or herbal bioactive compounds has been studied to create a sustainable and accurate release system of a herbal drug. Nanofibers can promote the activity of herbal bioactive compounds, reduce the effective dose, reduce side effects, and guide the final action site. One key factor to develop these release systems is to consider the chemical complexity of the bioactive compound to ensure the active form of the compound when it is released. Nanofibers could improve the solubility of the drug and bioavailability, improve compound stability, and reduce physical or chemical degradation rate and cytotoxicity such as control absorption rate of herbal extracts . S. epidermis, obtaining inhibition percentages of 94.24 ± 1.69% and 88.42 ± 2.81%, respectively. The authors mention the use of these nanofibers as a postoperative chemotherapy treatment or antimicrobial therapy. Sedghi et al.  reportedCellulose acetate nanofibers loaded with vitamins were fabricated by Taepaiboon et al.  for tranOther authors have encapsulated vitamin A in different concentrations in cress seed mucilage/PVA nanofibers to increase vitamin A solubility in aqueous media and decrease the vitamin degradation rate. Results show an encapsulation efficiency of 97%. Release activity was evaluated by simulated gastric and intestinal fluid, only 5.27% of the vitamin was released in gastric fluid . TavassoCentella asiatica (L.), possesses anti-inflammatory and the antioxidant activities as well as antidepressant-like effects. The Asiatcoside alginate/PVA/chitosan presented higher release activity than a commercial herbal cream. In addition, nanofibers activate factors for adhesion and proliferation of keratinocytes and fibroblast, collagen secretion and extracellular matrix remodeling such as VEGF, CD31, PCNA, IL-6, and TNF-α.Chantarodsakun et al.  reportedOne application that has provoked interest among both the scientific community and the consumer demands has been the incorporation of natural biopolymer ingredients for food packaging, which addresses environmental concerns by reducing the use of petroleum-based plastic packaging .Some of the most used polymers used in food packaging are chitosan and gelatin since their chemical composition allows them to have excellent inherent properties such as degradability, edibility, film-forming property, and compatible nature. Specifically, composites made by electrospinning of both materials have been reported to have enhanced properties suitable for this application such as food protection, promoting transportation, guaranteeing hygiene, and prolonging the shelf life of perishable items like those prone to stress, air, light, or even temperature . in vitro, proving its potential as thin edible coatings with good barrier properties, controlled moisture loss, and color retention that could be used in nutraceutical oral delivery applications.An example of this is reported by Leena et al.  with theMomordica charantia fruit extract to coaxial shell core zein/gelatin electrospun nanofibers in order to enhance its antioxidative content and potency has been reported due to its content of flavonoids and polyphenols. This method has proven to deliver high encapsulation efficiency and sufficient shelf stability, highlighting its potential as a stand-alone nutraceutical supplement or as an ingredient for fillers or edible wrappers in various food products [On the other hand, the incorporation of products .Another example of this application is the use of gelatin, chitosan, and PLA antibacterial nanofiber films elaborated by electrospinning. This method produced continuous, uniform nanofibers with improved thermal ability, moisture content, water-solubility, water vapor permeability, hydrophobic properties, and with a strong bactericidal effect in a short time, proving they are a safe, non-toxic, degradable option that ensured the safety, and quality of food products, increasing their shelf life .As previously mentioned, there has been a wide discussion about the general characteristics of drafts for wound healing, both mechanical and biological properties and function; nevertheless, just a few have been able to take their investigations beyond laboratory work to pre-clinic assays in animal models to ensure biological performance and toxicity effect in vivo.Nepeta dschuparensis plant was produced , revealing that after 21 days the wound healed faster by the incorporation of honey and Nepeta dschuparensis plant into the nanofiber mats [Lihospermi radix (LR) extract-containing bilayer scaffold was examined, where the porous morphology and high swelling ratio provided efficient exudate absorption ability with optimal characteristics for cell attachment and skin tissue regeneration [Some of these researchers have focused on the nanofiber’s ability to improve wound healing. For example, Mahmoudi, et al.  created ber mats . Moreoveneration . These iPinus halepensis bark (PHBE) was studied, showing that topical application of said patches on UV-inflamed skin significantly attenuated inflammation damage, reducing the healing period [S. aureus and E. coli [On the other hand, some other in vivo studies have researched other properties that promote healthcare applications. For example, a scaffold was made by electrospun chitosan microfibers to function as a support for attachment and viability of rat muscle-derived stem cells (rMDSCs), showing adequate 3D structure and porosity allowing sufficient cell seeding conditions to facilitate cell proliferation and differentiation by allowing the transport of nutrients and oxygen into and out the scaffold, observing new blood vessels and presence of macrophages, Kang et al. . Additiog period . Moreove E. coli . These iAccording to StatNano.com database , currentNanofibers are a potential system to load natural bioactive compounds from herbal extracts to produce effective active matrices which can be used in healthcare therapies. Nanofibers’ properties such as high area surface, mesh porosity, and similarity to ECM architectural structure give this technology an exponential growth in its application in healthcare and biomedical engineering. The use of natural polymers enables the optimization of biocompatibility and biodegradability of these types of nanomaterials. This review has shown novel applications of active nanofibers in the pharmaceutical field such as antimicrobial, antioxidant, drug release, tissue engineering nanofibers, as well as in the food packaging industry. This review provided comprehensive information on the design and development of natural-based polymer nanofibers incorporated with the incorporation of herbal medicines for the treatment of common diseases and their in vivo studies. It is important to note the constant need to optimize technique parameters as well as material sources to improve and develop eco-friendly and effective alternatives for the healthcare area and food industry.


Despite significant resource mobilization to address antimicrobial resistance (AMR), a persistent ‘action gap’ remains between AMR governance and the realization of societal change. Across international and national governance networks, AMR is widely recognized as an issue that goes beyond human health, requiring considerable and urgent attention from all sectors of society. In contrast, AMR awareness campaigns remain predominantly focused on framing AMR as a human health issue, with messages targeting individualistic antimicrobial consumption. In this article, we make the case that AMR awareness campaigns should frame the issue as one that goes beyond human health, in order to engage a greater number and broader array of stakeholders from across society. We argue that this could support efforts to reduce the AMR action gap, by making the issue more relevant to a wider range of stakeholders, expanding the sphere of responsibility and moving the focus from individualistic to societal-wide change. ,,,,The COVID-19 pandemic has demonstrated not only the far-reaching impact of a single untreatable infectious pathogen but also the scope for rapid, societal-wide change in response to such a threat. Antimicrobial resistance (AMR) has received considerable international attention and resources, and potentially poses a much greater long-term clinical, economic, social and environmental threat than COVID-19,,,,,,Widespread public support has been shown to be key for both bringing policy development to the fore as well as for successful implementation,,,,,,,The international AMR community has called for more research into optimizing AMR communications for local contexts, to improve understanding of localized AMR risk in order to evaluate/prioritize interventions and tailor solutions.