Developing dynamic organic ultralong room-temperature phosphorescent (URTP) materials is of practical importance in various applications but remains a challenge due to the difficulty in manipulating aggregate structures. Herein, we report a dish-like molecular architecture via a bottom-up way, featuring guest-responsive dynamic URTP. Through controlling local fragment motions in the molecular architecture, fascinating dynamic URTP performances can be achieved in response to reversible accommodation of various guests, including solvents, alkyl bromides and even carbon dioxide. Large-scale regulations of phosphorescence lifetime (100-fold) and intensity (10-fold) can be realized, presenting a maximum phosphorescence efficiency and lifetime of 78.8% and 483.1 ms, respectively. Moreover, such a dish-like molecular architecture is employed for temperature-dependent multiple information encryption and visual identification of linear alkyl bromides. This work can not only deepen our understanding to construct multifunctional organic aggregates, but also facilitate the design of high-performance dynamic URTP materials and enrich their practical applications. Developing dynamic organic ultralong roomtemperature phosphorescence (URTP) remains challenging due to the difficulty in manipulating aggregate structures. Herein, the authors report a dish-like molecular architecture featuring guest responsive dynamic URTP. Due to the unique photophysical property of long-lived emission lifetimes6, as well as inherent merits of mild preparation conditions, facile modification and environmental friendliness10, organic URTP materials are quite attractive for optoelectronics13, molecular imaging16, and many other fields19. In order to develop organic URTP materials with high efficiency and long lifetime, boosting the intersystem crossing (ISC) between singlet-triplet states and suppressing the nonradiative transition of triplet excitons in organic molecules are quite essential20. Following such basic principles, a lot of effort involving molecule engineering or two-component system fabrication, has gone into developing high-performance URTP materials27. Among them, of particular interest are those dynamic organic URTP materials, which can exhibit reversible and significant changes in URTP performances in response to external stimuli28. On account of their unique stimuli-responsive features, such as photoactivation and excitation dependence29, dynamic URTP materials have become a type of intelligent materials, demonstrating great promise for multicolor display, advanced anticounterfeiting, and many other crucial applications31. However, at present, most researches on dynamic URTP materials have only presented the URTP response to the stimulus of light33, leading to the scarcity in terms of the types of external stimuli that dynamic URTP materials can respond to34, which greatly impedes the further development of dynamic URTP materials for enriched practical applications.Organic ultralong room-temperature phosphorescence (URTP), generated from the radiative transition of triplet excitons in organic substance, is a persistent luminescence phenomenon after removal of the excitation source at room temperature35. Thus, a deep understanding of structure-property relationship and a rational design of aggregate structure are quite crucial for developing novel dynamic URTP materials. For example, when the motions of local fragments in the molecular architectures can be regulated upon external stimuli, the nonradiative decay rate (knr) of triplet excitons can be further controlled. As a result, regulation of URTP properties and even an on/off URTP switching can be eventually achieved. However, the driving forces for most assemblies of URTP molecules are intermolecular noncovalent interactions, such as hydrogen bonds, π–π stacking, van der Waals force, which feature poor directionality during assembly36. Therefore, even a tiny structural modification to the molecular building block can lead to a huge change in its molecular architecture due to the weak intermolecular interactions, bringing an uncertainty about its URTP performance, let alone its dynamic behaviors37. Thereby, seeking for suitable molecular units with room-temperature phosphorescence property, of which assembling behaviors can be almost maintained after structural modification, is a quite challenging but significant work. In this case, a bottom-up way can be followed to construct ideal molecular architectures with versatile optical performances, and the relationship between aggregate structures and dynamic URTP properties can be well investigated, which can provide new clues to enrich the types and applications of existing dynamic URTP materials.The performance of URTP is intimately related to the molecular structure and molecular arrangement of organic substance, especially to their aggregate structuresHere, we designed and synthesized a dish-like molecular architecture featuring guest-responsive dynamic URTP property through a bottom-up method. Through intermolecular C–H‧‧‧O = S interactions, antiparallel molecular chains are constructed, in which antiparallel organic building blocks are further interlocked. Small cavities with guest accommodation abilities are formed between flexible phenothiazine moieties, eventually establishing a dish-like molecular architecture. Through reversibly controlling the accommodation and removal behaviors of guest molecules, to the best of our knowledge, the first example of fascinating dynamic URTP property with guest response can be realized in this molecular architecture. When guest molecules are accommodated in the cavities, molecular vibrations can be effectively restrained, leading to the dramatical decrease in the nonradiative decay rate of triplet excitons, thereby generating the significant URTP phenomenon with an impressive a phosphorescence quantum yield up to 78.8% and a lifetime up to 483.1 ms under ambient conditions. Furthermore, we demonstrate the applications of this molecular architecture with the guest-responsive dynamic URTP property in multiple information encryption and decryption, as well as visual identification of linear alkyl bromides with alkyl chain length selectivity.H-carbazol-9-yl)phenyl)sulfonyl)phenyl)−10H-phenothiazine, henceforth denoted as CP, was designed and synthesized  spectroscopies, as well as the high-resolution mass spectrum (HRMS) and high-performance liquid chromatography (HPLC)  of 2.5% and a lifetime (τ) of 43.2 ms.The organic building block of this molecular architecture, namely 10-, the same packing mode constructed by antiparallel building blocks can all be continuously observed through intermolecular C–H‧‧‧O = S interactions with H‧‧‧O distances of 2.808–3.564 Å and intermolecular π–π interactions  solution of CP molecules  analysis, named CP-DMF, can be readily obtained by the vapor evaporation in a 42. The phosphorescence nature of this ultralong emission can be further confirmed by the temperature-dependent PL spectra, as well as the temperature-dependent lifetime decay profiles. When the temperature is decreased, both the phosphorescence intensity and lifetime of CP-DMF crystals gradually increased  quantum yield as high as 72.2%. Significantly, after turning off the UV-light source, the CP-DMF crystals show bright yellow green afterglow, which can be clearly observed by naked eyes even in the daylight condition  of triplet excitons can be efficiently decreased, leading to the generation of long-lived phosphorescence. Similarly, when the small cavities are occupied by guest molecules, the free volume inside the crystal is greatly reduced, which can also effectively impede the molecular motion, especially the motion of flexible phenothiazine moieties, thus suppress the nonradiative decay to produce intense phosphorescence emission with long lifetime.Due to the existence of the small cavities Fig. , the dyn2) adsorption/desorption isotherms of CP-Empty crystals are recorded at various temperatures  and a low-lying lowest triplet state (T1L), respectively (H/L represents high/low). According to the temperature-dependent lifetime decay profiles, when increasing the temperature from 100 to 300 K, the component ratio of T1H excitons is continuously decreased while the component ratio of T1L excitons is obviously increased  channel at elevated temperatures, thus producing the significant URTP phenomenon of CP-DMF crystals. To further uncover the TTET process, time-dependent density functional theory (TD-DFT) calculations based on the single-crystal structure of CP-DMF are carried out  are both local triplet (3LE) states originating from the phenothiazine-substituted diphenyl sulfone moiety in CP-DMF-87 and the carbazole moiety in CP-DMF-72, respectively  constant between the ground state (S0) and T1 (ξS0T1 = 2.83 cm−1) of CP-DMF-87 is much larger than that of CP-DMF-72 (ξS0T1 = 0.23 cm−1), which implies that both of CP-DMF-87 and CP-DMF-72 can emit phosphorescence from their T1 state, respectively. Accordingly, the T1H and T1L emissions of CP-DMF crystals peaking at 510 and 550 nm are dominated by the phenothiazine-substituted diphenyl sulfone moiety in CP-DMF-87 and the carbazole moiety in CP-DMF-72, respectively.As revealed in Fig. sed Fig. . These dely Fig. . In addiH-phenothiazine) and 9,9’-)bis(9H-carbazole), named 2 P and 2 C, respectively) are synthesized  can be readily transferred to the T1H dominated by the phenothiazine-substituted diphenyl sulfone moiety. However, due to the existence of empty cavities surround by flexible phenothiazine moieties, intense molecular thermal motion occurs in CP-Empty crystals. Consequently, the nonradiative transitions dominate the decays of triplet excitons in T1H. Even a very small fraction of the triplet excitons can be transferred to T1L through the TTET channel, their nonradiative relaxation still play a dominant role, resulting in a poor phosphorescence performance. But when guest molecules are accommodated in these cavities, the molecular architecture, particularly the flexible phenothiazine moieties, can be stabilized by the steric effect and host-guest interactions. Nonradiative transitions can be suppressed to a great extent. Thus, most of relatively short-lived triplet excitons undergo radiative decays to produce the T1H phosphorescence. And also, some of the triplet excitons can be further transferred to the carbazole-based T1L through a TTET process, thus generating long-lived triplet excitons to produce the significant URTP emission of CP-DMF crystals. In a word, a fascinating dynamic URTP phenomenon with a nearly 100-fold regulation of phosphorescence lifetime and a 10-fold regulation of phosphorescence intensity can be achieved through guest accommodation/removal to manipulate the degree of nonradiative transitions in the dish-like molecular architecture.To further decipher this standpoint, two reference compounds, namely phenothiazine-disubstituted diphenyl sulfone and carbazole-disubstituted diphenyl sulfone )bis is observed, while only delayed emissions (negative absorption) are captured in transient absorption spectra , dimethyl sulfoxide (DMSO) and dichloromethane (DCM) can all be accommodated in CP-Empty crystals, producing crystals of CP-THF, CP-DMSO, and CP-DCM. Molecular assembling forms of CP-THF, CP-DMSO, and CP-DCM are all consistent with that of CP-DMF  with alkyl chain length selectivity is also demonstrated. Interestingly, the maximum dimension of window size in this molecular architecture (8.936 Å) is larger than the molecular dimensions of alkyl bromides from 2 C to 5 C  via a bottom-up method. Through intermolecular C–H‧‧‧O = S interactions, antiparallel molecular chains are constructed, in which antiparallel organic building blocks are further interlocked. Small cavities are formed between flexible phenothiazine moieties, eventually establishing a dish-like molecular architecture. Through reversibly controlling the accommodation and removal behaviors of guest molecules, the first example of a molecular architecture exhibiting the dynamic URTP property with fascinating guest response can be realized. Various guests including different solvents, alkyl bromides and even carbon dioxide, can all induce the dynamic URTP performance of this dish-like molecular architecture with a good reversibility. When the cavities are occupied by guest molecules, molecular motion can be effectively restrained by the steric effect and host-guest interactions. Nonradiative decay of triplet excitons can thus be efficiently suppressed, leading to the significant URTP phenomenon in this dish-like molecular architecture with a highest phosphorescence quantum yield up to 78.8% and a longest lifetime up to 483.1 ms under ambient conditions. This work not only provides a valuable strategy to design novel dynamic URTP materials, but also offers an opportunity to develop a convenient platform for multiple information encryption and decryption, visual molecular identification, intelligent COf]indole was purchased from TCI. N,N-dimethylformamide (DMF), dichloromethane (DCM), tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), 1,2-dichlorobenzene (o-DCB), n-hexane (nH), and ethanol (EtOH) were all purchased as analytical grade from Guangzhou Dongzheng Co. (China).Bis(p-fluorophenyl)sulfone, 10H-phenothiazine, carbazole, alkyl bromides, and sodium hydride (NaH) were purchased from J&K Scientific. 1-Bromo-2-nitrobenzene and phenylboronic acid were purchased from Energy Chemical. 1H-benzo[1H and 13C nuclear magnetic resonance (NMR) spectra were measured on a Bruker AVANCE III spectrometer in DMSO-d6, with tetramethylsilane  as the internal standard. High-resolution mass spectra (HRMS) were obtained on a GCT Premier CAB 048 mass spectrometer. High-performance liquid chromatography (HPLC) spectrum was measured on an Agilent Technologies 1260 Infinity with a column of Poroshell 120 . Photoluminescence and phosphorescence spectra were measured using an Ocean Optics QE65 Pro with a 365 nm Rhinospectrum RhinoLED as the excitation source or a Horiba Scientific Fluorolog-3 spectrofluorometer. The lifetime profiles and time-resolved emission spectra were carried out with a Horiba Scientific Fluorolog-3 spectrofluorometer. The luminescence quantum yields were determined by using a Horiba Scientific Fluorolog-3 spectrofluorometer equipped with a Horiba Scientific Quanta-φ calibrated integrating sphere. Transient absorption spectra were obtained in air using an Ocean Optics QE65 Pro with a 365 nm Rhinospectrum RhinoLED as the excitation source and an Ocean Optics DH-2000-BAL as UV-Vis-NIR light source. The photoluminescence images were taken by the Canon 750D digital camera. Temperature-dependent CO2 gas adsorption/desorption isotherms were obtained by a Micromeritics ASAP 2020 surface area analyzer. The thermogravimetric analyses (TGA) data were obtained on a Shimadzu TGA-50 thermogravimetric analyzer. Powder X-ray diffraction (PXRD) data were collected using a Rigaku X-ray diffractometer (D/max-2200). The single-crystal X-ray diffraction (SXRD) data of single crystals were collected from an Agilent Technologies Gemini A Ultra system with Cu-Kα radiation. The structures were resolved and refined using direct methods with OLEX2. Solvent-accessible void spaces (free volumes) were calculated by mercury.The single crystals of CP-DMF, CP-THF, and CP-DMSO suitable for the SXRD analysis were grown by solvent evaporation of CP solution in DMF, THF, and DMSO, respectively, at room temperature for 3 days. The single-crystal quality of CP-DCM is not good enough for the SXRD analysis because the solvent molecules escaped easily from crystals, leading to disordered phenothiazine moiety and poor-quality X-ray diffraction patterns.Supplementary InformationPeer Review File


Recently, nanofibers have come to be considered one of the sustainable routes with enormous applicability in different fields, such as wastewater treatment. Electrospun nanofibers can be fabricated from various materials, such as synthetic and natural polymers, and contribute to the synthesis of novel nanomaterials and nanocomposites. Therefore, they have promising properties, such as an interconnected porous structure, light weight, high porosity, and large surface area, and are easily modified with other polymeric materials or nanomaterials to enhance their suitability for specific applications. As such, this review surveys recent progress made in the use of electrospun nanofibers to purify polluted water, wherein the distinctive characteristics of this type of nanofiber are essential when using them to remove organic and inorganic pollutants from wastewater, as well as for oil/water (O/W) separation. Recently, due to overpopulation, urbanization, increases in different industrial and human activities, landfill expansion, mining activities, and urban wastewater, various environmental problems related to water pollution are becoming more worrying and critical ,2. Huge Electrospun nanofiber mats can be modified to meet the needs of certain applications, such as by blending functional additives into the electrospinning solution , incorpoMany researchers have studied the applications of electrospun nanofibers, and addressed topics related to specific fields, such as the purification and treatment of wastewater ,14,15,16Recent reviews have discussed the effective removal of various pollutants using nanomaterials, and outlined solutions to water challenges . AdditioOrganic contaminants in water, such as dyes, phenols, detergents, pharmaceuticals, and others, can be discharged from the domestic sewage, agriculture, food, paper, and leather industries. Such wastes require a high amount of oxygen to complete the oxidative decomposition process, which decreases the quantity of dissolved oxygen in the water, thereby threatening the lives of aquatic organisms and ecosystems ,35.When some dyes are introduced to surface water, they produce degradable byproducts that can have carcinogenic effects, and most of them have hydrophobic properties, accumulate in the water, and can penetrate the tissues of some aquatic organisms and humans. Moreover, dyes are extremely toxic pollutants, and are discharged from various industries, such as plastics, rubber, and textile, into the ecosystem and water resources . The effOne of the most dangerous side effects of the rapid growth of many industries, such as electroplating, tanneries, battery manufacturing, electroplating, etc., is the discharging of effluents contaminated with toxic heavy metal ions into water bodies . Even atThe processing of natural oil is the main source of crude oil and its derivatives. Leakage and spill accidents occurring during the utilization and transportation of oil  have resSince the beginning of this century, nanotechnology and nanostructured materials have attracted considerable attention in most research areas due to their unique properties. Nanomaterials are described as materials that are <100 nm in at least one dimension. The chemical and physical properties of materials at this size are greatly improved due to their less bulky size. For example, the density of binding sites at the nanoscale is attributed to their high surface area. Moreover, nanomaterials provide enhanced surface free energy, thus increasing the materials’ surface reactivity. These advantages make nanomaterials useful in water treatment applications . Among tMany pollutants have been discharged into freshwater supplies and their surrounding ecosystems, including organic and inorganic pollutants. Oil spills have serious impacts on ecosystems and human health ,45,46. TRecently, the demand for high-quality water has increased dramatically worldwide ,51,52,53Therefore, nanofibrous structures fabricated by electrospinning methods play a considerable role, and have shown significant potential for use in wastewater treatment due to their favorable characteristics related to removing the organic and inorganic pollutants from aqueous media ,52,53,54Various novel and promising nanofibers and their potential modifications have been assessed for their use in removing different organic pollutants from wastewater. Self-sustained electrospun polyacrylonitrile (PAN) nanofiber-supported polyamide (PA) thin-film composite (PA/PAN-eTFC) membranes are one such material that was prepared and tested for the removal of tetracycline (TC) from wastewater. Initially, the support for the PAN nanofiber was synthesized by electrospinning a. After An electrospinning approach was employed to prepare a highly efficient molecular filter membrane composed of crosslinked insoluble poly-CD nanofibers, and this achieved the excellent and rapid uptake of organic pollutants from a liquid environment . Table 1With the rapid development of dye-related industries, huge amounts of wastewater are continuously discharged into surrounding environments. These dyes, such as methylene blue (MB), may be degraded, and produce carcinogens and toxic products. These pollutants are dangerous, and can adversely affect the environment and human health. Thus, novel nanofibers have been developed to eliminate such pollutants from water resources ,80,81,82Moreover, according to the Langmuir isothermal model, the DA@PDA nanofiber membrane possessed an MB adsorption capacity of 88.2 mg/g, which was 8.6-fold greater than DA nanofibers . Additio−1  trimethyl ammonium chloride (PMETAC) in poly(ether sulfone) (PES) solution. There, the quaternary ammonium salt polymer of PMETAC donated positive charges to the NFMs, enabling them to kill bacteria and adsorb anionic dyes, as represented in 3+). The prepared membranes (NFMs-NH3+) and dodecyl sulfate contain adsorbents that help to eliminate anionic pollutants such as methyl orange, as shown in 2) [The electrospun nanofibers with specific surface areas facilitate the accessibility of the functional aldehyde groups, and undergo an efficient Schiff base reaction after the reduction and protonation reaction. These three-step reactions transform the original hydrophobic ANFMs into a hydrophilic nanofiber mat carrying functional ammonium groups (NFMs-NHwn in 2)  and polywn in 2) , were fa2) fibers were fabricated using sol-gel and electrospinning strategies, utilizing polyvinylpyrrolidone and zirconium butoxide as precursors, followed by treatments at various temperatures and examination for dye removal [However, these metallic ion nanoparticle catalysts are generally found in powder forms, which easily aggregate in liquid media and form a suspension that cannot be recovered or separated after use . We have removal .2/N-doped carbon nanofiber (TiO2/NCNF) mat with “memory catalysis” activity was prepared by combining electrospinning and carbonization methods. In contrast to the structure of TiO2/NCNFs, the addition of a Ti resource to the PAN solution leads to the self-assembly of TiO2 in the NCNF support, enhancing the flexibility and mechanical functionality of the catalysts, providing highly active sites, and ensuring easy recovery from treated water. Moreover, the N-graphitized carbon can collect the electrons released from TiO2 under irradiation light, and then reuse them in the dark to perform “memory catalysis” [2, zinc oxide (ZnO) is found to be one of the most commonly applied metal oxides due to its promising intrinsic properties; it has greater photosensitivity and wide bandgaps, and has a porous structure [Additionally, a novel flexible TiOtalysis” . In additructure . As suchtructure .Additionally, catalytically active porous and hollow titania nanofibers encapsulating gold nanoparticles (AuNPs) were prepared using the conjugation of sol-gel chemistry and a coaxial electrospinning strategy. This strategy involves a shell composed of a mixture of PVP and titania sol, while the core is composed of a mixture of poly(4-vinyl pyridine) (P4VP) and pre-prepared AuNPs. The core–shell nanofibers were thermally treated stepwise up to 600 °C, which caused the dissociation and decomposition of the organic materials of the nanofibers. This behavior gave rise to porous and hollow titania nanofibers, with the catalytic AuNPs established in the inner wall of the titania shell . On the To prevent the agglomeration of bimetallic composites, the SMX was immobilized on support materials, and a polymeric membrane for surface impregnation was utilized in the treatment of chlorinated organic compounds . Recent 2+  [2+ [2+ [2+ [2+, Zn2+ [2+, Mg2+ [6+ [5+ [In the last decade, many researchers have focused their work on removing the inorganic pollutants from wastewater using nanofibers fabricated via the electrospinning technique, as shown in ls ions) ,119,121,ons) [2+ ,117,120, [2+ [2+ ,107,108, [2+ [2+ , Cd2+, Z2+, Zn2+ , Ca2+, M2+, Mg2+ , heavy m2+, Mg2+ ,124, Cr6Mg2+ [6+ ,138,139, [6+ [5+ ,133.3+, Tb3+, and Nd3+. Moreover, it can be regenerated and reused for about eight cycles [3+ and Y3+ [6+). The binding reagents were either nitrogen-based (Aliquat®336(Aq)) or phosphorous-containing hexadecylphosphonic acid (HPDA). Then, bis(2-ethylhexyl) phosphate (HDEHP) was mixed (at 1–3 wt. %) with PAN sol-gel, and we utilized electrospinning to yield a modified nanofibers membrane. For comparison, PAN nanofibers were also loaded with amidoxime (AO) moieties, a group with a high capacity to adsorb uranium (VI) (U6+). Aq-containing materials containing quaternary ammonium groups appear to sequester U6+ by electrostatic interactions; the adsorption rates of such materials are limited, and will be high at pH = 7, where positively charged N-groups attract negatively charged complexes of uranium. On the other hand, HDPA and HDEHP act effectively at acidic pH levels, where the surface complexation of U6+ likely drives absorptivity. Complexation using amidoxime was effective at different pH values, although U6+ removal through surface precipitation may also occur at circumneutral pH values and with higher dissolved uranium concentrations [For lanthanide and actinide, a poly/sodium hexametaphosphate hydrogel nanofiber (PVA/SHMP HENF) with a 3D structure was prepared via an electrospinning technique in one step. The crosslinking reaction was carried out by thermal treatment using citric acid (CA) as the crosslinking agent. The fabricated PVA/SHMP HENF showed high swelling properties, high pH stability, and the remarkable removal for some lanthanide metals, such as Lat cycles . Additio and Y3+ . The obttrations .2O3/PAN nanofibers are an example of these promising nanofibers, which are fabricated by the electrospinning technique followed by a simple hydrothermal process [2O3 (α-Fe2O3/PAN) as an effective adsorbent, and this is used to remove Pb2+ from wastewater [Electrospun nanofibers play vital roles in reducing and taking heavy metals from wastewater; heavy metals are considered a serious environmental pollutant, and pose a tremendous threat to human health and other living things. Heavy metal ions such as Cd, Cu, Pb, and Hg are regarded as a major class of inorganic contaminants that pollute water and have dangerous physiological impacts , along w process . In thisstewater .2+, as illustrated in 3+ ion as a coagulant during a typical wet-spinning process. Based on various interactions, such as ionic bonding and electrostatic interactions between Fe3+ and the -COOH groups on CMCNF, the CF presented a better mechanical function than the pure GO fiber. The GO/CMCNF-Fe3+ CF enabled enhanced lead (Pb2+) adsorption [2+ from an aqueous solution [2+, along with other metal cations such as Cu2+, Ca2+, Co2+, Zn2+, and Ni2+, was investigated using a macrocyclic pyridone pentamer-modified nanofiber prepared via electrospinning [Furthermore, GO has gained great attention in the decontamination of heavy metal ions from aqueous media, but it has many disadvantages, as it can be dispersed in a liquid phase and cannot be recovered easily. Consequently, a new composite fiber (CF), made of a GO/carboxymethyl cellulose nanofibril (CMCNF) composite, was fabricated as an effective and durable adsorbent for Pbsorption . Additiosolution . The remspinning . The regspinning .2+ ions from aqueous media. It achieved considerable adsorptive capacity due to the synthesized round-shaped nanofibers, as shown in 2+ from aqueous media. The addition of phytic acid enhances the hydrophilicity and decreases the mechanical features to a certain extent, but protects certain mechanical properties, as represented [To overcome the disadvantages of the application of calcium alginate aerogels to adsorb heavy metals, a novel alginate composite nanofiber with enhanced toughness was fabricated by electrospinning, using GO as the reinforcing filler, for adsorbing Pbresented .2+ from aqueous media, such as electrospun nanofibers coated with a hydrogel layer with a tunable thickness [2/TiO2) porous nanofibers membranes (STPNMs) composed of interfiber mesopores and interfiber macropores, and functionalized by an amino-salinization reaction to yield the membrane (ASTPNMs) [2+) and (Pb2+), such as crosslink polyvinyl alcohol (PVA) nanofibers [Recent publications have reported various types of novel electrospun nanofibers with promising properties, used for the removal of Pbhickness , and eleASTPNMs) . Additionofibers , mesopornofibers , and nannofibers .2+), many electrospinning nanofibers were synthesized with improved absorptivity and selectivity. A poly/chitosan (PVA/Chi) nanofiber membrane was created by the electrospinning method for the selective and improved uptake of lead (Pb2+) and cadmium (Cd2+) ions from acidic solutions [2+ and Cd2+ ions in the presence of competing ions [2+ and Cd2+ ions from aqueous solutions. The functionalization process improves the hydrophilicity properties of the membrane, giving rise to better antifouling features and higher permeability [2 composite nanofibers were fabricated using the electrospinning technique to eliminate Pb2+, Cd2+, and Cr6+ ions—via the adsorption and membrane filtration methods—from aqueous solutions [2+, Pb2+, and Cu2+ in aqueous solutions [In the presence of other heavy metal ions such as cadmium (Cdolutions . The fabing ions . Additioeability . PAN/chiolutions . Likewisolutions .2+), the excessive accumulation of heavy metal ions, such as (Cu2+), in the surrounding environment could cause many diseases and will pose detrimental effects. Therefore, the removal of these metals ions and their harmful effects has attracted the interest of numerous researchers. Electrospinning nanofibers offers an effective and sustainable way of producing a suitable nanomaterial for the removal of these metal ions. Porous poly(L-lactic acid) (PLLA) nanofiber membranes with a large surface area were created by electrospinning and post-acetone curing, and acted as a substrate to deposit chitosan (Chi) and remove Cu2+ from aqueous solutions. Chi was covered onto a porous nanofibrous membrane through a direct soaking coating method, and acted as an efficient sorbent due to –NH2 and –OH, which are chelating sites for the chelation of Cu2+ [2+ from aqueous solutions [For copper ion (Cu of Cu2+ . Additioolutions .2+ [2+ [2 nanoparticles were applied as pore-forming reagents. Carboxyl groups (–COOH) ionized into carboxylate ions (–COO-) have a high affinity for Cu2+ uptake. Moreover, the tree-like porous structure provided a high specific surface area, and enhanced the adsorption capacities [2+ [On the other hand, different types of bio-polymer, such as proteins, can be considered promising materials for absorbing heavy metal ions via their functional groups. Barley is one of the most important protein sources in the world, and it contains about 80.13% protein. Consequently, Guan et al. (2019) fabricated hordein nanofibers via the electrospinning method . This wo2+ . Additio2+ [2+ . The prepacities . Additioties [2+ .2+ pollutants into valuable Cu nanoparticles that can increase the functionality of catalysis, and the fabricated PAA-SA-NFHs with uniformly coated Cu-nanoparticles showed a preformed catalytic activity [2+ and other metals ions, such as (TiO2/ZnO) nanofibers, which anchor onto the sewage sludge carbon’s (SSC) surface for the removal of Cu2+, Ni2+, and COD from aqueous solutions [2+, Ni2+, Cd2+, and Ag+ from an aqueous solution [Furthermore, this work has outlined a sustainable approach to transforming toxic Cuactivity . Other eolutions . Furthersolution .2+, in the processing and refining of many raw ore minerals such as zinc sources, cadmium occurs naturally, and is mainly leached during the refining process as a by-product. Cd has very dangerous effects on human health and ecosystems, where it bioaccumulates in plants, invertebrates, and vertebrates. In recent works, electrospun nanofibers have been investigated as suitable nanomaterials to remove Cd2+. A nanofibrous electrospun nonwoven adsorbent, prepared from chitosan and phosphorylated nanocellulose (PNC), was investigated for use in the uptake of Cd2+ ions from aqueous media, for the sake of water sustainability [2+ ions from aqueous media [2+ associated with other metals ions [2+ and Zn2+ from an aqueous solution [2-PAN) hybrid membrane was fabricated and examined for use in the extraction of various metal ions  and cationic dyes (such as methylene blue (MB)) from polluted drinking water sources [2+, Pb2+, Ni2+, Mn2+, Zn2+, and Cu2+) from wastewater over time [As regards Cdnability . A compous media . To achius media . Other nals ions ,118,121.solution . These csolution . A devel2+ and Mg2+ [Recently, the electrospinning method was applied to fabricate various types of nanofibers, such as cellulose acetate (CA) nanofiber with various contents  of iron-modified nanozeolite (Fe-MNZ). The prepared nanofibers removed Ni2+ ions from simulated wastewater . Furtherand Mg2+ . Additioand Mg2+ .6+ ions is a pressing issue for the environment and human health, given its high toxicity and carcinogenicity. It is discharged into the environment along with other metal ions from the mineral, textile, paint, and petroleum refining industries. During the last few years, electrospun nanofiber mats have been created that function via numerous wastewater purification techniques. Therefore, the unique characteristics of electrospun nanofibrous membranes have attracted great attention. Accordingly, many electrospun nanofibrous membranes have been fabricated and utilized to remove Cr6+ from aqueous media [6+ ions via the photoreduction strategy in water purification processes [2)NPs, doped into PAN nanofibers were applied for the removal of Cr6+ from an aqueous solution [6+, such as free-standing PVA/PAN nanofibrous composite membranes with interpenetrating nanofibers structures [2 n-fib@Mat [The contamination of water resources with toxic Crus media ,138,139.rocesses . Additiosolution . Other nructures , the PAN-fib@Mat , environ-fib@Mat , novel c-fib@Mat , and uni-fib@Mat .4+), arsenic (As5+), cadmium (Cd2+), iron (Fe), copper (Cu2+), and cobalt (Co2+), can co-exist with Cr6+ ions; these metal ions have higher toxic effects compared with the same metal ions in another oxidation state. For example, Se4+ exhibits about 10 times higher toxicity than Se6+ [4+ and Cr6+ ions were eliminated from aqueous solutions by magnetite nanoparticles (MNPs)/graphene (G) nanosheets doped with polyvinyl alcohol (PVA) and cellulose acetate (CA) electrospun nanofibers [3O4/TiO2) were fabricated and studied for the adsorption of Cr6+ and As5+ [6+ and As5+ from water [Other toxic heavy metal ions, including selenium  [In the last decade, electrospun nanofiber membranes have been widely investigated and utilized for wastewater treatment. One of the most effective membranes are nanofibrous composite membranes based on polyvinyl alcohol (PVA) and polyacrylonitrile (PAN) , which astewater . To deve bagasse . To imprnd Co2+) .2O3 nanoparticles that were prepared via a thermal solvent process, in a polyacrylonitrile solution were investigated for the removal of As5+. The nanofiber achieved the excellent removal of As5+ using batch and filtration techniques [On the other hand, various processes have been investigated for the removal and elimination of arsenate from arsenate-containing water. Many electrospun nanofibers have been identified as novel adsorbents of great significance ,133. LanAnnually, large volumes of oily sewage are discharged into the environment due to oil spill incidents, and other oil-related activities, such as those of the food, textile, tannery, and metallurgy industries, which have caused serious water pollution problems . Consequ2, TiO2, Al2O3, and CeO2) were prepared via the blow-spinning of a blended solution of polylactic acid (PLA) and metal oxide nanoparticles (NPs). The obtained results show that introducing SiO2 NPs massively increases the hydrophobicity of the membranes. The PLA/SiO2 nanofiber membranes possessed a higher separation efficiency than pure PLA, PLA/TiO2, PLA/Al2O3, and PLA/CeO2 nanofiber membranes, with good separation performance (~100%) and permeation flux , as well as a prominent oil sorption capacity (19.9 g/g for n-hexane) [−1 and the ability to run for over 10 adsorption–desorption cycles [Membrane technology has been successfully utilized to treat and purify different wastewaters due to its considerable economic and technical merits . However-hexane) . Addition cycles . On the n cycles .3+-based superhydrophobic membrane presents anti-impact, low-adhesive and self-cleaning properties, and furthermore, has a high capacity to purify oil/water mixtures: a high flux up to 6935 Lm−2 h−1, with a separation ability of >99% in water containing oil at <5 ppm, even after 20 uses. In addition, the membrane shows considerable UV-shielding function due to the inherent UV-absorbing property of tannic acid.Recently, metal–phenolic coordination materials have gained great attention in the engineering of functional nanomaterials when seeking to fabricate multifunctional nanofibrous membranes that perform well in different oil/water mixtures . ConsequMoreover, the membrane also has an antibacterial ability, high biocompatibility, high mechanical strength, and good resistance to harsh conditions . Additio2 nanofiber webs for oil/water separation by adding hydrothermally prepared rGO/TiO2 nanoparticles into an electrospun solution. From oil–water separation studies, it can be noted that PVDF/rGO/TiO2 nanofiber membranes with an rGO/TiO2 quantity of 3% have the best oil removal abilities, at 98.46% [Some raw materials such as polyvinylidene fluoride (PVDF) are considered amongst the most common utilized in the fabrication of materials used in separation techniques. PVDF has promising properties, such as perfect chemical/thermal stability, high mechanical properties, as well as excellent film/fiber fabrication characteristics . Therefot 98.46% .The surfaces wettability of some polymeric membranes can be enhanced by the addition of certain metal oxides nanoparticles, such as (ZnO-NPs), which can contribute to improving the antibacterial property of ZnO-NP functionalized electrospun polyacrylonitrile membranes . Hence, In the last few years, to improve antifouling membranes, three main types of hydrophilic additives, known as inorganic NPs, and hydrophilic and amphiphilic polymers, have been utilized to adjust the surfaces of fabricated membranes . ZwitterCarbon nanotubes (CNTs) recently gained much attention due to their promising properties. Therefore, the electrospinning technique was used to produce thin-film nanofibrous nanocomposite (TFNC) membranes with notable antifouling and self-cleaning characteristics . As suchThe fabrication of a mesh filter membrane to separate water/oil with higher permeating flux and high oil intrusion pressure has remained a significant and considerable challenge .The ultrathin microporous membrane was investigated by coating a stainless steel mesh filter with electrospun PAA-embedded poly(vinylidene fluoride) to form PAA-g-PVDF nanofibers. The network form of the nanofiber layer decreased the size of the pore of the stainless steel mesh and improved its oil pressure rejection capacity, while keeping a highly efficient separation area to maintain the extreme permeability function of the mesh filter membrane, along with the high permeating flux and high oil intrusion pressure at the same time . The fabOn the other hand, higher-performance renewable nanomaterials with lower or even net zero carbon emissions are the main goal in the context of the desired sustainable and eco-friendly future. Therefore, various natural materials are considered promising candidates to be applied in the water purification processes. This review has surveyed the recent progress made in the fabrication of different forms of electrospun nanofibers and their applications in wastewater treatment. It concludes that these fabricated forms of nanofibers, especially the electrospun nanofibers utilized in the purification techniques, embody the concept of sustainable development.In this review, many works demonstrate that electrospun nanofibers and their functionalized forms have been widely utilized to treat wastewater from various pollutants, such as organic and inorganic pollutants and oil/water separation, and they have illustrated considerable effects.Due to the unique characteristics of nanofibers, they are considered a promising novel class of nanomaterials useful for diverse applications, such as water purification. Various methods have been investigated for the manufacturing of submicron polymeric nanofibers, such as nanolithography, self-assembly, multi-component spinning, flash spinning, electrospinning, etc. . It can Despite the great efforts made to develop and improve upon the unique structures and functions of the nanofibers used for wastewater treatment and oil/water separation, many limitations must still be addressed. The properties of the polymer, composite, and nanofiber membranes are significantly affected by the media’s chemical and physical properties and the surrounding environment. Therefore, the properties of the fabricated nanofibers, such as their eco-friendly, degradability, renewability, non-toxicity, mechanical and thermal properties, as well as their availability, long-term durability, and cost-effectiveness, should be considered and further optimized to eliminate the other disadvantages. Additionally, the adhesion of pollutants, microorganism contaminations, biofilm formation, and eventual fouling during treatment processes are other serious challenges facing wastewater treatment using the various multifunctional electrospun nanofiber materials. Therefore, strategies are needed to develop and synthesize novel nanofiber materials with specific characteristics and self-cleaning features. Additionally, further efforts should be made to improve the surface-coating and impregnation methods, in order to reduce the fouling of membranes using suitable nanomaterials and to anchor the nanomaterials onto the surfaces of nanofiber materials. Additionally, the investigation of further techniques for the separation and retention of suspended nanomaterials after treatment is required to decrease the overall costs. More attention must still be paid to the fabrication of novel and renewable nanomaterials and functionalized nanofibers with specific properties and mechanical characteristics, with lower or even net zero carbon emissions, and with powerful capabilities in the purification of various pollutants from wastewater.


Akkermansia muciniphila and members of the Enterobacteriaceae, Enterococcaceae, and Lactobacillaceae families acquire resistance and remain recalcitrant. We identify specific genes conferring resistance against the antibiotics in the corresponding metagenome-assembled genomes (MAGs) and trace their origins within each genome. Here we show that, while mobile genetic elements (MGEs), including bacteriophages and plasmids, contribute to the spread of ARGs, integrons represent key factors mediating AMR in the antibiotic-treated mice. Our findings suggest that a single course of antibiotics alone may act as the selective sweep driving ARG acquisition and incidence in gut commensals over a single mammalian lifespan.The emergence and spread of antimicrobial resistance (AMR) represent an ever-growing healthcare challenge worldwide. Nevertheless, the mechanisms and timescales shaping this resistome remain elusive. Using an antibiotic cocktail administered to a murine model along with a longitudinal sampling strategy, we identify the mechanisms by which gut commensals acquire antimicrobial resistance genes (ARGs) after a single antibiotic course. While most of the resident bacterial populations are depleted due to the treatment,  et al. show that a single antibiotic treatment leads to resistance in bacteria such as Akkermansia muciniphila and that integrons play a key role in mediating this resistance.Antimicrobial resistance represents an ongoing silent pandemic. Here, de Nies  In addition, they are extensively used in animal husbandry5 and also in animal models for studying the gut microbiome11. Concomitantly, their prevalence and administration are widespread in developing and developed countries alike13, whereby antibiotics are easily accessible. However, many bacterial taxa have evolved antimicrobial resistance (AMR) to several classes of antibiotics, and multidrug-resistant bacteria have now emerged, preventing the comprehensive treatment of infections and resulting in a growing number of deaths14. Due to the overall rise in resistance, as well as a lack in the development of new antibiotics, AMR has emerged as a growing global threat to human health15. Therefore, a clear understanding of the selective sweeps (processes or mechanisms driving increased frequency of genetic variation) underlying the evolution, timescale, and transmission of ARGs is of crucial importance.Prior to the advent of antibiotics, bacterial infections were the leading cause of disease and mortality in humans. Antibiotic usage is now commonplace in treating infections16. Although the majority of bacteria are harmless commensals, which do not cause disease, they still provide a rich repertoire of resistance genes17. As such, through HGT, opportunistic pathogens may acquire resistance genes from other commensals. Therefore, MGEs conferring multidrug resistance are considered the cause for the wide dissemination of the now globally prevalent AMR “superbugs”14. Furthermore, while resistant bacteria may remain latent, they contribute to the overall reservoir of AMR based on which resistant pathogens may emerge once selective pressure due to antibiotics is built up19. Compounding this phenomenon, the overuse of antibiotics both in the treatment of human disease and in animal husbandry has fueled the build-up of AMR globally14. With the realization that the gut microbiome plays crucial role in disease etiology20, antibiotic-treated animal models remain one of the methods by which the intestinal microbiome is studied21. The potential caveats, however, of using antibiotics for modulating the endogenous populations, including the emergence of AMR is unknown.In general terms, bacteria can acquire and develop AMR through two distinct genetic mechanisms, either through the acquisition of spontaneous mutations during replication of the bacterial genome or through the accumulation and dissemination of resistance genes via mobile genetic elements (MGEs). MGEs, such as bacteriophages (phages), plasmids, and integrons, promote the transfer of resistance genes between bacterial populations through the process of horizontal gene transfer (HGT)Akkermansia muciniphila and species within Enterobacteriaceae, Enterococcaceae, and Lactibacillaceae families are recalcitrant to antibiotic treatment. Moreover, we describe the key roles played by integrons in mediating antibiotic resistance against the administered antibiotic cocktail. Our observations allow us to test whether specific bacteria, including commensals, are more susceptible or capable of acquiring ARGs, as well as assess the influence of HGT on shaping the gut microbiome’s resistome.In this work, utilizing a mouse model, we assess the effect of selective antibiotic sweeps on the evolution of AMR within the commensal gut microbiome over a single mammalian lifespan after a single course of antibiotic treatment. We find that taxa such To assess the effect of selective pressures on AMR evolution, two groups of mice were single-housed in specific-pathogen-free conditions, whereby one of the groups was treated with an antibiotic cocktail  representing broad-spectrum antibiotic treatment regimens used in preoperative procedures and in animal models (“Methods”). Longitudinal fecal samples were collected from the control and antibiotic-treated mice prior to treatment, i.e., day 0, and subsequently immediately after treatment, i.e., day 7, and two weeks after treatment, i.e., day 21 Fig. .Fig. 1ExAkkermansia muciniphila and Ligilactobacillus spp. on day 21 after antibiotic treatment , despite a near-total depletion of the microbiota at day 7 in the treated mice  were significantly decreased or depleted entirely at days 7 and 21  in pathways relating to signaling molecules  on days 7 and 21 compared to the controls . We found that the overall ARG abundance in the treated mice was also significantly enriched at days 7 and 21, when compared to the control mice at the same timepoints. On days 7 and 21, we specifically observed AMR against aminoglycoside, aminoglycoside:aminocoumarin, beta-lactam, fluoroquinolone, fosfomycin, glycopeptide, fusidic-acid, phenicol, mupirocin, triclosan and multidrug to be significantly enriched within the treated group , at day 7 we detected taxa that consisted predominantly of Bacteroidales spp.  verifying the full-length matches for horizontally-transferred genes, we assessed whether ARGs were transferred across MAGs within the timepoints. We did not observe differences in the overall number of HGT events between the control and treatment groups at all timepoints (Fisher’s exact test). However, to further assess whether HGT contributes to ARG spread, HGT events were specifically linked to AMR genes. We did not find a significant correlation between AMR and HGT in the control and treated mice across all timepoints, although Akkermansia spp. was involved in AMR-associated HGT events in 6/8  of the mice treated with antibiotics , Akkermansia was only involved in AMR-associated HGT in 3/8  of the control mice  and post-treatment (days 7 and 21). Using MetaCHIPAkkermansia muciniphila and Ligilactobacillus spp. Interestingly, pangenome analyses of Akkermansia muciniphila revealed the acquisition of several genes at day 21 compared to day 0, including those mediated by integrases  in ARGs associated with complete (presence of attC and intI genes) integrons in mice at day 21 compared to day 0 and also when compared to the controls  were further analyzed to identify their putative genomic locations on phages or plasmids, since they are known to be carriers of integrons, thus elaborating on the method of integron-mediate AMR transmission. Interestingly, we identified several integron-mediated ARG cassettes encoded on plasmids at day 21 in the antibiotic-treated mice Fig. b.e, and Enterobacteriaceae  as a standard therapy33. Similarly, preoperative antibiotic prophylaxis in humans is a common practice and typically involves three antibiotics 35 These are usually administered individually while vancomycin in combination with other antibiotics  has been proposed for treatment of methicillin-resistant Staphylococcus aureus36. Here, we hypothesized that antibiotic treatment would lead to an evolution of AMR in the commensal gut microbiome population within a single animal lifespan and tested our hypothesis in a wild-type mouse cohort.The classes and uses of antibiotics have been extensively developed since the fateful discovery of “mold juice” by Alexander Fleming38 and in varying combinations in line with some clinical procedures39. We observed that Akkermansia muciniphila was significantly enriched whilst most taxa were depleted in mice post-treatment, which is in line with other reports42 where vancomycin treatment alone led to propagation of A. muciniphila or its dominance in the resistant commensal population. The resistance of this taxon can specifically be attributed to the presence of β-lactamase and nitroimidazole resistance genes reported by van Passel et al.43. These findings also agree with the report by Palleja et al. in which the authors found that species harboring β-lactam resistance genes were positively selected during antibiotic exposure44, which is likely the case in our study since we observed higher ARG abundances at day 21 and not prior to antibiotic treatment. Alternatively, the observed ARGs could also be due to the acquisition of resistance genes possibly via lateral or horizontal gene transfer as reported previously by Guo et al.45.The antibiotics  were chosen given their utility in several mouse modelsA. muciniphila, we also observed an enrichment in the functional complement of A. muciniphila with respect to signaling molecules, specifically quorum sensing and cyclic dinucleotide signaling. Microbial communities are characterized by emergent properties that themselves are primarily shaped by microbial interactions46. These interactions include intra- and extracellular signaling, such as quorum-sensing (QS) and cyclic dinucleotide sensing, as a means of adapting to internal and external stimuli47. Due to the paucity of external stimuli from other bacteria following antibiotic treatment, it is plausible that QS functions were selected for as a means for recalcitrant community members to ramp up signaling functions to induce antibiotic tolerance. This is in line with reports of collective antibiotic tolerance48, contributing towards AMR, which may be mediated via QS molecules leading to bacterial resistance gene expression in a density-dependent manner48. Furthermore, QS molecules have also been reported to regulate secondary metabolite synthesis49. However, we observed a depletion in genes involved in secondary metabolite synthesis following antibiotic treatment which is expected since a majority of the endogenous population is depleted. Alternatively, this phenomenon also suggests that selection for genes involved in signaling and secondary metabolite synthesis are somewhat uncoupled in our experimental murine model and, thus, are subject to different selective sweeps. Overall, our results highlight the role of key functions conferred by specific bacterial taxa in antibiotic-exposed communities and shed light on the shorter-term evolutionary processes shaping community assembly and composition.In addition to an overall enrichment in aminoglycoside (neomycin), beta-lactam (ampicillin), and glycopeptide (vancomycin). We, however, did not recover any resistance genes against nitroimidazoles (metronidazole). Additionally, we found that several taxa in mice treated with antibiotics were directly linked to the resistance categories of the antibiotics that they were treated with. This suggests that the selective pressure of the administered antibiotics may lead to real-time evolution of AMR within the gut microbiome. This is in line with a recent report by Xu et al.50 albeit in a different mouse model , who found that treatment with single antibiotics lead to an increased abundance of resistance genes. Intriguingly, they only noted considerable levels of MGE-mediated horizontal gene transfer for fosfomycin but did not observe high levels of ARGs associated with integrases. In our study, we found that while phages and plasmids contributed to both HGT and AMR, integrons were also a key factor in AMR dissemination. Despite the decrease in overall diversity and number of taxa in antibiotic-treated mice, we observed a significantly increased prevalence of ‘complete integron’-mediated AMR. In accordance with previous reports51, we found that gene cassettes encoding ARGs are localized and mediated via MGEs, specifically plasmids. This has further implications since mobility allows penetration and potential integration of AMR into new taxa. Importantly, in conjunction with our findings about the survival and resistance of A. muciniphila, we found that several integrons associated with AMR were directly linked to this taxon.Given the nature of the antibiotic cocktail treatment, we found several related ARGs in the metagenomes of the treated mice. More importantly, we observed significantly increased resistance at day 21, against three out of the four antibiotics used in our study protocol: A. muciniphila is thought to be plastic45, our analyses emphasize the role of integrons in mediating AMR in commensals, including within this taxon. In addition, it is presently unclear whether the acquired ARGs are expressed, requiring the need for both experimental and cross-validation using methods such as metatranscriptomics to resolve gene expression. Given the association of A. muciniphila with Parkinson’s and other chronic diseases, our findings highlight the need to understand the role of integrons in mediating AMR within and beyond this taxon. Taken together, our data show that AMR is relevant to studies involving antibiotic treatment, especially within the commensal gut microbiome population. Our study is built on a systemic, and longitudinal design to understand the stage at which the resistance genes are acquired following antibiotic treatment. Overall, we highlight the need for understanding the real-time evolution of AMR in microbiome research, including functional and evolutionary consequences of integron-mediated AMR.Concerted knowledge has concentrated on pathogenic bacteria, and lately the emergence of AMR. Although the genome of The animal experiment was performed according to all applicable laws and regulations, after receiving approval by the institution’s Animal Experimentation Ethics Committee at UL (AEEC) and the Ministry of Agriculture, Viniculture and Rural Development (LUPA 2019/99). The care and use of animals for research purposes was conducted according to the EU Directive 2010/63/EU, as well as the Grand-Ducal Regulation of 11 January 2013 on the protection of animals used for scientific purposes. These included the justification of the use of animals, their welfare and the incorporation of the principles of the “3Rs” .52. For this, we estimated the Jensen–Shannon Divergences (JSD) of the microbial profiles of the antibiotic-treated (cefprozil) and control groups. Based on the observed JSD, the inter-group variability was significantly high, thereby highlighting a minimum sample size of three mice per group to attain a power of 80 and a 5% alpha error rate, reflecting changes in microbial composition . The animals were maintained under standard habitat conditions  with a 12:12 light cycle. Two groups of mice were established (control and treatment), and each group contained 8 animals . Antibiotics, ampicillin (1 g/L), vancomycin (500 mg/L), metronidazole (1 g/L), and neomycin (1 g/L) were chosen for their utility in several mouse models38 and in line with some preoperative procedures39. They were administered as a cocktail within the drinking water to the treatment group starting at 8 weeks of age. Antibiotics were administered during a period of one week, after which the change was made to regular drinking water for the duration of the recovery period. Fecal samples were collected prior to treatment and subsequently daily for a duration of 19 days (both treatment and recovery phase) starting prior to the antibiotic treatment till take down  were obtained from the same vendor and the same location in the vendor facility. After a 7-day quarantine and subsequent acclimation period of one week, mice were maintained in single housing conditions. Mice were housed in Allentown NexGen Mouse 500 (194 mm × 130 mm × 381 mm) cages  with JRS Rehofix Corncob bedding. Mice had access to reverse osmosis water with 2ppm of chlorine fed own Fig. .53. A minimum of 200 ng of total DNA was recovered from all the samples, yielding sufficient DNA for metagenomic sequencing including high-resolution, artefact-curated metagenomic data for subsequent analyses54. DNA extracted from all timepoints was thereafter stored at −80 °C until further use.A total of 48 fecal samples were obtained across three timepoints, i.e., prior to treatment: day 0, immediately after treatment: day 7, and after recovery: day 21, from each of the mice. 50 mg of frozen stool samples were aseptically weighed into sterile vials. Genomic DNA was isolated with the DNeasy PowerSoil Kit  including an additional incubation step at 65 °C and milling, as described previouslyAll DNA samples were subjected to random shotgun sequencing. Briefly, 200 ng of DNA was used for metagenomic library preparation using the Westburg NGS DNA Library Prep Kit . The genomic DNA was enzymatically fragmented for 12 min and DNA libraries were prepared without PCR amplification. The average insert size of libraries was 480 bp. Prepared libraries were quantified using Qubit  and quality checked on a Bioanalyzer instrument . Sequencing was performed at the LCSB sequencing platform (RRID SCR_021931) on a NextSeq500  instrument using 2×150bp read lengths.55 was used to process paired forward and reverse reads using the built-in metagenomic workflow as previously described56. The workflow includes pre-processing, assembly, genome reconstruction, and functional annotation of genes based on custom databases in a reproducible manner. After trimming the adapters, the preprocessing step included the removal of Mus musculus (GRCm38.p6 (GCA_000001635.8); retrieved on 16-May-2020 from https://www.ensembl.org/Mus_musculus/Info/Index) reads. Thereafter the de novo assembly was performed using the MEGAHIT (version 2.0) assembler57. Default IMP parameters were retained for all samples. Metagenomic operational taxonomic unit (mOTU) profiles were generated from the trimmed and preprocessed reads to generate microbiome profiles for the control and treatment groups using mOTUs v2.5.158. Concurrently, we used MetaBAT259 and MaxBin260 for binning in addition to an in-house binning methodology previously described56 for genome reconstructions, i.e., MAGs. Subsequently, we obtained a non-redundant set of MAGs using DASTool v1.1.461 with a score threshold of 0.7 for downstream analyses, and those with a minimum completion of 90% and less than 5% contamination as assessed by CheckM v1.1.362. Taxonomy was assigned to the MAGs using the extensive database packaged with gtdbtk v1.7.024. To generate pangenomes, we collected all the bins taxonomically identified as Akkermansia muciniphila and used the anvi’o-based pangenome workflow described by Eren et al. (http://merenlab.org/2016/11/08/pangenomics-v2/)63. One of the treated mice (#16), was excluded from the pangenome analyses due to the unavailability of MAGs.The Integrated Meta-omic Pipeline 64. For the assembly, we used the same kmer settings as the assembly setup in IMP, i.e., 21, 33, 55, and 77, in a paired-end format with 24 threads. Subsequently, ARGs were collapsed into categories based on the Comprehensive Antibiotic Resistance Database (CARD)65 and identified using PathoFact. Thereafter, the relative abundance of the ARGs was calculated using the Rnum_Gi method described by Hu et al.66.We used PathoFact v1.0, a pipeline for the prediction of virulence factors and AMR genes, to predict and identify ARGs within our metagenomes. The assembly files from individual samples were used as input for the AMR analyses. To assess the relevance of metaplasmidSPAdes and metaviralSPAdes for identifying plasmid and viral sequences respectively, we used de novo SPAdes assembler v3.15.425 with a modified setting of full-length match of genes of interest to ensure robustness of the findings. The confirmation of ARGs and their associated mode of transfer was also performed manually alongside this by mapping identical 1Kbp flanking regions, via the same pipeline. Briefly, groups of genes among all input MAGs with maximum average identity were considered putative HGT genes. To validate the predicted candidates, a pairwise BLASTN was used to assess each pair of flanking regions of 10 Kbp. Visual representations of the genomic regions were extracted alongside the results for visual interpretation and inspection.Identified ARGs and their categories were linked to associated bacterial taxonomy using the metagenomic bin classifications. Furthermore, utilizing PathoFact, ARGs were linked to predicted mobile genetic elements (MGEs: phages and plasmids) to identify probable transmission of AMR between taxa. More specifically, to link both the MGEs and the taxonomy to the ARGs, we mapped the genes to assembled contigs, followed by identifying the corresponding bins (MAGs) to which the contigs belonged. By considering all different predictions of MGEs, a final classification was made based on the genomic contexts of the ARGs encoded on plasmids, phages, or chromosomes, including the classification of those that could not be resolved (ambiguous). The ARGs that could not be assigned to either the MGEs or bacterial chromosomes were further referred to as unclassified genomic elements. Certain ARGs were encoded on both the bacterial chromosome and phage genomes. HGT of ARGs was assessed using MetaCHIP v1.0attC sites were identified by HattCI67 while for the annotation of the intI sites a BLAST database was created using the intI variant sequences from the UniProt database68. Only those contigs where both the signature genetic regions (intI and attC) were found were annotated as having ‘complete’ integron elements. We also identified the MAGs along with which the integrons were binned, thus linking the integrons to the reconstructed genomes. The ARG information was overlaid onto this to identify contigs where integrons were linked with ARGs. Furthermore, we used sequence coordinates to identify integron localization, i.e., chromosome, plasmid, or phage localization of gene cassettes, incomplete and complete integrons on MGEs. This information was used for downstream differential analyses.The assemblies generated via IMP were used to assess the presence and abundance of integrons within the metagenomes. Briefly, 69 was used to generate the figures for describing the longitudinal weight measurements of the mice. DESeq226 and Wilcoxon rank-sum tests with FDR-adjustments for multiple testing were used to assess significant differences for the AMR and taxonomic analyses whereas a paired two-way ANOVA  within the nlme package was used for identifying statistically significant differences in the integron profiles. Chord diagrams for the HGT events were generated using scripts found within the MetaCHIP package25 while the pangenome visualizations were obtained using anvi’o63.Figures for the study including visualizations derived from the taxonomic and functional, were created using version 3.6 of the R statistical software package. GraphPadFurther information on research design is available in the Supplementary InformationPeer Review FileReporting Summary


Nanotechnology is one of the most promising technologies available today, holding tremendous potential for biomedical and healthcare applications. In this field, there is an increasing interest in the use of polymeric micro/nanofibers for the construction of biomedical structures. Due to its potential applications in various fields like pharmaceutics and biomedicine, the electrospinning process has gained considerable attention for producing nano-sized fibers. Electrospun nanofiber membranes have been used in drug delivery, controlled drug release, regenerative medicine, tissue engineering, biosensing, stent coating, implants, cosmetics, facial masks, and theranostics. Various natural and synthetic polymers have been successfully electrospun into ultrafine fibers. Although biopolymers demonstrate exciting properties such as good biocompatibility, non-toxicity, and biodegradability, they possess poor mechanical properties. Hybrid nanofibers from bio and synthetic nanofibers combine the characteristics of biopolymers with those of synthetic polymers, such as high mechanical strength and stability. In addition, a variety of functional agents, such as nanoparticles and biomolecules, can be incorporated into nanofibers to create multifunctional hybrid nanofibers. Due to the remarkable properties of hybrid nanofibers, the latest research on the unique properties of hybrid nanofibers is highlighted in this study. Moreover, various established hybrid nanofiber fabrication techniques, especially the electrospinning-based methods, as well as emerging strategies for the characterization of hybrid nanofibers, are summarized. Finally, the development and application of electrospun hybrid nanofibers in biomedical applications are discussed. Currently, nanomaterials do not have an internationally accepted definition. Based on nanomaterials characteristics, they can be designed as nanoparticles (NPs), nanowires, nanotubes, nanofibers, and nanorods . RecentlIn recent years, electrospinning has gained a great deal of attention to create nanofibers. The major reasons for the popularity of the electrospinning technique are its cost-efficiency, ability to manufacture continuous nanofibers, high flexibility, and simplicity in setting up and controlling nanofiber diameters, compositions, and orientations based on the desired application . Many maA wide variety of biodegradable and biocompatible polymers  can be combined to create hybrid mats . BlendinIn this literature review, the recent research performed on the fabrication and characterization of hybrid electrospun nanofibers, not limited to different blended polymers but considering a broader set of polymers with functional agents, such as drugs, biomolecules, and NPs, is discussed. Also, a summary of the biomedical applications of electrospun hybrid nanofibers in drug delivery, tissue engineering, wound healing, and biosensors is provided. Finally, recent challenges in mechanical strength, degradation, and industrial mass fabrication of electrospun nanofibers, along with prospects of hybrid nanofibers for tissue engineering and biomedical applications, are discussed.Hybrid nanofibers have received significant attention owing to their unique properties. These materials show unique magnetic, optoelectrical, and biological properties essential for a wide range of applications in optics, energy generation and storage, environment, medicine, and biotechnology . VariousCurrently, many efforts have been made in the direction of up-scaling the production and improving the nanofiber properties. Among various fabrication techniques, electrospinning is a promising method that offers the opportunity to produce nanofibers using different materials in various fibrous assemblies. In recent years, electrospinning received much attention in both academics and industry due to its simplicity, applicability over a wide range of materials, and low cost .Electrospinning is a dry spinning technique used to fabricate continuous nanofibers . Fibers This technology can generate nanofibers with a high surface-to-volume ratio and a structure similar to the extracellular matrix (ECM), receiving much attention for research in biomedicine . SeveralExtensive use of electrospinning in different industries and high-tech fields has led to infrastructure for the mass production of related equipment, making it commercially available alongside nanofibrous material . This haBlend electrospinning is considered the simplest method, based on mixing different polymers or polymers with functional agents to prepare a single fluid for electrospinning . In blenIn order to enhance the efficiency of nanofibers, many modifications have been performed on electrospinning techniques through the years. Developing core-sheath nanofibers utilizing coaxial or triaxial electrospinning is one of these modifications. In this strategy, a polymeric nanofiber in the core is covered by another polymer as a shell  Figure . NanofibInterestingly, two different release patterns from one delivery system can be reached by incorporating different drugs into the core and shell phases. Coaxial or triaxial electrospinning is the most common technique for preparing hybrid nanofibers. This technique is based on a concurrent flow of a core and sheath solution from separate capillaries to form a nanofiber . In thisEmulsion electrospinning is one of the most straightforward techniques for preparing hybrid nanofibers. Many scientists have developed nanofibers using emulsion electrospinning to incorporate different therapeutic agents into fibers in the form of core-sheath structures. Emulsion electrospinning has some superiorities compared to traditional techniques, such as allowing the incorporation of lipophilic compounds in low-cost hydrophilic polymers with no need for organic solvents, which are highly limited in food systems. Emulsion electrospinning has a similar setup to blend electrospinning in which immiscible solutions are concurrently spun to produce core-sheath structures. In this method, initially, the emulsification of bioactive agents is performed by adding surfactant into the solution to form a water-in-oil emulsion and thereafter, the as-prepared emulsion is mixed with a polymer solution . EvaporaThe side-by-side electrospinning technique is a two-compartment system commonly used to prepare Janus nanofibers . In JanuElectrospinning not only plays an important role in the construction of 2D nanomaterials, but also in the production of 3D scaffolds. Conventional electrospinning techniques use a charged nozzle containing polymer solution(s) at a certain distance from a static collector and form 2D mats. The 2D electrospinning processes produce tightly packed nanofiber scaffolds with only surface pores due to the sheet-like assembly. These scaffolds have a limited thickness and are unable to infiltrate cells or diffuse nutrients. Thus, researchers try to develop 3D electrospun nanofiber scaffolds to better mimic the ECM’s architecture and morphology. The advantages of electrospinning techniques for fabricating 3D nanofibers include control over morphology and tuning of fiber size and scaffold porosity. Moreover, 3D structures offer a greater surface area than 2D mats, which makes them very promising for various applications  . HoweverConsiderable effort has been devoted to fabricating 3D scaffolds, employing auxiliary equipment or modified electrospinning apparatuses. The most commonly used techniques for 3D electrospun scaffolds are multilayer electrospinning, wet electrospinning, template-assisted electrospinning, electrospinning with post-processing , self-assembly electrospinning, and electrospinning combined with 3D printing.Multilayer electrospinning is one of several promising strategies to fabricate 3D hybrid structures to better mimic the morphological and physicochemical properties of tissues and organs. Multilayer scaffolds can be fabricated by electrospinning nanofibers onto other electrospun fiber mats in a layer-by-layer pattern. Indeed, multilayer electrospinning is the stacking of electrospun layers by sequential electrospinning processes or co-electrospinning . AdjustiWet or liquid electrospinning is derived from the conventional electrospinning process. In a wet electrospinning process, a liquid/coagulation bath in a metal container is replaced with a solid collector in the electrospinning setup  Keirouz. The colTemplate-assisted electrospinning, based on modifying the shape of the collector, is another technique used for fabricating 3D scaffolds. In this method, utilizing an insulated poly (methyl methacrylate) (PMMA) mask on the collecting copper plate to focus the collection of fibers makes it possible to synthesize scaffolds with 3 mm thickness in a short time . In ordeInterestingly, in a recent study, a 3D hydrogel structure as a grounded collector was used instead of the conventional electroconductive collector . The mulIn some cases, the template may be added to or shaped during the electrospinning process. For example, it has been shown that microcrystals created during low-temperature electrospinning under high humidity can act as removable pore templates between the fibers, leading to the fabrication of highly porous 3D scaffolds. In a similar study, NaCl crystals enhanced nanofibrous scaffolds’ pore size and increased cell proliferation. This technology can also be combined with microfluidic devices to improve cell culture conditions under constant flow .3D hybrid scaffolds can also be made from 2D structures using conventional methods followed by post-processing approaches, such as electrospraying, short fiber freeze-drying, gas-foaming, and various other methods. Therefore, post-processing approaches mostly rely on electrospun nanofibers and scarcely need significant changes in the conventional electrospinning setup.in situ gas foaming within the pores of the 2D nanofibrous mats as the driving force. In this approach, gas bubbles produced in situ via a chemical reaction  or the addition of an inert gas  lead to the creation of highly porous 3D scaffolds (The gas-foaming technique is a simple and versatile post-processing electrospinning approach that enables the conversion of 2D mats to 3D scaffolds. This method is based on caffolds .4) is the most used foaming agent in the gas-foaming process. However, it needs to be dissolved in water to produce the necessary hydrogen through a chemical reaction with water. Therefore, NaBH4 is not applicable to the processing of water-soluble materials. Also, owing to the strong reactivity of NaBH4, materials with weak mechanical stability may be destroyed during foaming. In such cases, using carbon dioxide is an appropriate choice for gas-foaming post-treatment. In this process, polymeric material along with carbon dioxide is placed in a chamber at an increasing pressure until the dissolution of the gas in the polymer. When the pressure is relieved, large pores are formed thermodynamically  in the polymeric solution. In other words, adding such compounds to the polymeric mixtures can induce repulsive forces between nanofibers during the electrospinning process, resulting in 3D porous structures (The structure and pore size of scaffolds can be controlled by modulating the polarizability of electrospun fibers by including some conductive additives such as phosphoric acid (Hructures . It is n3D bioprinting or additive manufacturing (AM) technology can bridge the gap between artificial tissue scaffolds and natural tissues . 3D prinAdditionally, CAD-based 3D printing technology has recently gained considerable attention, allowing the fabrication of cellular, acellular, and hybrid scaffolds . 3D biopTo overcome this challenge, the combination of 3D printing with electrospinning can produce multifunctional hybrid nanofibers with highly porous interconnected structures and improved mechanical properties . DiffereThe properties of hybrid nanofibers made by blending only polymers are limited, and much can be performed to improve their biological, mechanical, electrical, or optical features. The mentioned properties can be improved by immobilizing functional agents in nanofibers and forming multifunctional hybrid nanofibers. These functional agents include inorganic/organic NPs, biomolecules , drug molecules, etc. The immobilization of various functional moieties in nanofiber matrix can considerably improve mechanical, physicochemical, and biological properties .Immobilization of NPs in hybrid nanofibers provides exceptional properties, combining NPs’ advantages with polymer properties. These nanofibers may also have more functions, including photothermal properties, magnetic responses, biosensing, antibacterial properties, and drug delivery capabilities. Furthermore, NPs can improve nanofibers’ physicochemical and mechanical properties and stability .An increasing number of published articles on nanofiber-nanoparticle hybrids show the high potential of such multifunctional nanofibers for different applications . Diversein situ, growth of NPs on nanofibers  physicochemical properties of the system  , 2) procVarious polymers from different sources can be combined and spun to fabricate hybrid nanofibers. Selection of the polymers is a critical step for producing nanofibers with specific characteristics suited to particular applications. The ideal polymer for biomedical applications must be biodegradable, safe, biocompatible, moderately hydrophilic, and have proper mechanical strength. These polymers can be obtained from natural or synthetic sources, each having different advantages and disadvantages. The polymer type must be selected based on the end-use of the nanofibers . Table 2Natural polymers are a popular choice in electrospinning for biomedical applications. They can come from animal or plant resources or other living organisms, making them mostly biodegradable, biocompatible, and non-toxic with low antigenicity . AdditioThe high quality of nanofibers can be assured during the production process by characterizing nanofibers according to test metrics that correlate with the material’s functional properties. Single fiber characterization provides fundamental data for understanding the relationship between nanofiber’s structure and properties. Also, depending on their ultimate utilization, various methods have been developed to characterize nanofiber scaffolds . For exaPorosity refers to the empty spaces between nanofiber components. These pores are located on the surface or inside of nanofibers, making them very lightweight and providing a large surface area . Porous Geometric characterizations are able to determine the diameter, size distribution, orientation, and morphology of the fabricated fibers. Morphological features of nanofibers can be measured by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and transmission electron microscopy (TEM).SEM is the most commonly used method due to its availability and ease of use. By measuring apparent density from the SEM images and comparing it to the bulk density of the electrospun polymers, SEM can reveal information about the fiber diameter/alignment, pore diameter, and porosity of scaffolds . In conjThe tensile test is one of the most frequently used methods for determining nanofiber’s mechanical properties. Tensile tests define factors such as young’s modulus, tensile strength, and strain at the break of polymeric fibers. Previous studies have reported that hybrid scaffolds exhibit better mechanical strength .XRD spectroscopy is a non-destructive and well-established method to detect changes in crystallinity after electrospinning. The crystallinity of many different hybrid electrospun scaffolds has been clarified using the XRD method . The cryInformation about nanofiber composition and chemical characterizations can be gleaned from FTIR analysis . FurtherRaman spectroscopy is typically complemented by infrared (IR) spectroscopy . Raman sWettability or hydrophilicity of the surface is important for understanding the outer surface chemistry of electrospun nanofibers. Of note, the hydrophilicity of nanofiber surface is vital in biological studies due to better cell attachment and proliferation .Thermal properties of hybrid electrospun nanofibers can be evaluated by differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA) methods .DSC consists of a cooling or heating test to maintain the sample and reference at a constant temperature. The DSC can be used to determine the solid-state properties of active pharmaceutical agents and the encapsulation efficiency of crystalline compounds and identify the configuration of the macromolecules in nanofibers and their interactions  .TGA is employed to determine the encapsulation efficiency of hybrid nanofibers, the stability, and the solvents evaporation of formulations by measuring material weight (loss or gain) as a function of altering the heating temperature .Biocompatibility and mechanical properties are important parameters in biomedical applications. The previously mentioned positive characteristics of electrospun nanofibers, high porosity, versatility, and high surface-to-volume ratio, make them a good choice for different biomedical applications such as drug delivery, tissue engineering, wound dressing, and biosensors  Figure .To date, various drug delivery systems have been developed to enhance the clinical efficiency of drugs and decrease their toxic effects compared to conventional dosage forms. Some characteristics of an ideal drug delivery system include high loading capacity and encapsulation efficiency, ease of operation, low cost, and controlled drug release. All of the mentioned criteria can be achieved using electrospun nanofibers .Electrospun nanofibers have received a great deal of attention among different drug delivery systems due to their favorable characteristics. A wide variety of materials and drugs, ranging from small molecule drugs, such as antibiotics, to macromolecules, like proteins and DNA, can be loaded into electrospun nanofibers for improving their bioavailability or attaining controlled release . DiffereIn recent years, a large part of studies in the area of controlled-release drug delivery has focused on developing stimuli-responsive systems. The drug release in these systems is based on response to changes in environmental parameters, including pH, temperature, light, electrical, and magnetic fields . Electroin vitro (® L100-55 (EL100-55), as a pH-sensitive polymer, were used to prepare electrospun nanofibers  and dexamethasone, the steroid anti-inflammatory drug, to decrease immune response in tissue engineering. They showed a controlled release of dexamethasone over time, and stem cells could also successfully attach and proliferate on the nanofibers in vitro . In anotin vitro . The memnofibers . They shStaphylococcus aureus and Pseudomonas aeruginosa. They possessed better antibacterial activity than the control group  have the potential to be utilized for improving mechanical, structural, and drug delivery properties in electrospun nanofibers. In a recent study performed by 3O4 NPs were mixed with a PLGA solution to prepare the electrospinning solution. After electrospinning, a shell of polydopamine was grown through a simple immersion on the surface of as-prepared magnetic nanofibers. The polydopamine-based shell with numerous catechol moieties on the surface of nanofibers was able to attach to bortezomib (BTZ), an anticancer agent. According to the results, they found this smart system highly beneficial owing to its higher therapeutic efficacy and low toxicity towards normal cells and also the potential of magnetic NPs for repeated hyperthermia application and controlled drug release in the tumor tissue  and enhance the bioavailability of the drug . Polymerp. aeruginosa and S. aureus. Considering the fast erosion of scaffolds, drug release was fast, taking place within 20 min. Thus, this designed nanofibrous scaffold was applicable for short-term medication .For instance, in vivo study exhibited that the healing time in test groups was three times faster than in the control group. It seems that as-prepared electrospun nanofibers have a high potential for clinical use  is a major component of cartilage that plays a critical role in regulating many chondrocytes signaling pathways . Moreove3D scaffolds are more desirable for tissue engineering than 2D scaffolds . Hence, Nanofibers can also be applied for vascular tissue engineering and renovating blood vessels for clinical applications. The high porosity of nanofibers facilitates nutrient and gaseous transports leading to angiogenesis and vascular regeneration . In desiInterestingly, the PCL/fibrin scaffold exhibited a better response to vasoconstrictors and vasodilators as the native artery compared to the pure PCL graft. In addition, similar to the native artery, a PCL/fibrin scaffold could increase cell infiltration, tissue regeneration, and deposition of ECM proteins, including collagen, elastin, and GAGs. They suggested PCL/fibrin scaffold as a promising tissue engineering material for vascular grafts . Table 6Myocardial infarction is one of the most prevalent disorders, leading to cardiomyocyte death due to an interruption in nutrient and oxygen transport in the myocardium. Following the infraction, the myocardium usually loses its regeneration ability. Therefore, implanting tissue-engineered myocardium into the damaged tissue is the easiest approach to compensate for tissue damage resulting from the infarction. The main challenge in myocardial tissue regeneration is providing an environment similar to native cardiac tissue . Electrovia electrospinning. These conductive nanofibrous sheets had the ability to enhance cardiomyocytes’ maturation and spontaneous beating. In addition, they could form cardiomyocyte-based 3D bioactuators with tubular and folding shapes, which indicated their great potential in cardiac tissue engineering and bioactuators’ applications  can be a promising strategy as an alternative to nerve autografts for improving functional outcomes. NGCs are tubular biostructures used to bridge nerve injury sites. Thus, they act as a guide and protective microenvironment for the regeneration and restoration of function in the target area . DesigneFor instance, Wound healing is a complex process with different stages, including hemostasis, inflammation, proliferation, and remodeling. One of the critical steps in wound management is wound dressing to shield the wound from external risk factors and accelerate the healing process . CharactWounds refer to skin deformities or tissue discontinuities caused by physical or thermal injury or underlying ailments. Generally, wounds are divided into acute and chronic wounds. Acute wounds are usually caused by surface burns, chemical, and mechanical injuries, etc. Acute wounds can go through the normal process of wound healing. On the other hand, chronic wounds cannot go through this process and may be open for more than 1 month . Chronicvia electrospun dressings is a promising strategy for treating severe wounds -functionalized PVA/PVP/glycerol electrospun scaffolds for wound dressing  induced diabetic rats and accelerated wound closure rate. Altogether, the composite nanofibrous electrospun scaffolds with a stage-wise release pattern of multiple angiogenic factors can be a promising candidate for chronic wound healing .dl-lactide)-poly-(ethylene glycol) (PELA)/PEG nanofibers with core-sheath structures by emulsion electrospinning for skin wound healing in diabetic rats  and collagen type 1(COL1) genes as well as rat wound re-epithelialization in vivo (Lawsone (Law) is a quinone derived from the leaves of the henna plant. In a recent study, lawsone was incorporated into PCL/gelatin nanofiber by the coaxial electrospinning technique and tested for wound healing activity. This compound was successfully entrapped into the core polymer. As a result of wound healing activity, PCL/gelatin/Law mats of 0.5% and 1% increased the expression of transforming growth factor-beta , sedative, and wound healing properties for burns and insect bites . HajialiBiosensors are analytical devices that play an important role in both research and the market—owing to their potential to detect various substrates for clinical diagnostics , food anMoreover, the high porosity of nanofibers leads to low mass transport resistance, thereby elevating analyte diffusion through the sensing layer . AccordiIn recent years, electrospinning technology has attracted increasing attention for fabricating micro or nanofibers. Electrospun nanofibers have some outstanding characteristics, including high surface-to-volume ratios, high porosity, low cost, easy fabrication and surface functionalization, and adjustable fiber morphology, making them attractive for biomedical use. A wide range of polymers with different sources can be applied for hybrid nanofiber fabrication. Generally, polymers are divided into natural and synthetic polymers. Biopolymers are non-toxic with higher biocompatibility and biodegradability compared to synthetic polymers.Additionally, they may possess unique biological activities such as antibacterial, antifungal, and anticancer effects. Despite all their benefits, biopolymers have poor mechanical properties compared to synthetic polymers. Hence, biopolymers and synthetic polymers can be combined and make hybrid nanofibers to benefit from the advantages of both polymers. There are several techniques to prepare electrospun hybrid nanofibers with different structures. Furthermore, functional agents such as drugs, biomolecules, and NPs can be incorporated into a polymeric matrix to fabricate multifunctional hybrid nanofibers.The main and basic setup to fabricate hybrid nanofibers include: 1) blend electrospinning, 2) coaxial or triaxial electrospinning, 3) emulsion electrospinning, and 4) side-by-side electrospinning. The future will bring more advanced and complex multi-fluid electrospinning technologies for producing nanofibers with unique collective properties.in vivo degradation of nanofibers is a complicated process 4) Industrial fabrication of electrospun hybrid nanofibers remains challenging. It is noteworthy that although nanofibers have shown promising results in preclinical studies, many clinical studies are still needed to ensure their clinical applications.Electrospun nanofibers are ideal candidates for various biomedical and healthcare applications, especially the antimicrobial treatment of bacteria-related biofilms, orthopedic implant-related infections, tissue scaffolds, drug delivery, wound dressings, and biosensors. However, some challenges should be considered to improve the functionality of nanofibers. For instance: 1) the pore size of nanofibrous scaffolds is too small, making cell infiltration difficult. 2) The mechanical strength of electrospun nanofiber-based scaffolds is usually not enough for hard tissue regeneration. 3) Controlling In the future, it is necessary to improve the function of electrospun nanofibers and develop new functional nanofibers to provide more technical support for biomedical use. As a result of the trend and prospects, nanofiber-miniaturized systems are increasingly used for next-generation biomedicine platforms in clinical and point-of-care studies. In addition, the combination of 3D printing and computational simulation with electrospinning is the potential trend. Ultimately, we believe all these will be achieved in the future with the development of science and technology.