CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national phase application of PCT Application No. PCT/KR2018/016339, filed on Dec. 20, 2018, which claims priority to Korean Patent Application No. 10-2017-0177114, filed on Dec. 21, 2017. The entire disclosure of the applications identified in this paragraph is incorporated herein by reference.

FIELD

The present invention relates to a composite for transdermal delivery in which a metal-organic framework (MOF) and nanocellulose are used.

In addition, the present invention relates to a cosmetic composition comprising the composite for transdermal delivery.

Furthermore, the present invention relates to a method for preparing the composite for transdermal delivery.

BACKGROUND

To stabilize an active ingredient and increase transdermal efficiency, effort and study for utilizing a transdermal delivery system to functional cosmetics have been actively carried out. Because of developing functional materials, various functionalization methods for imparting higher stability to such materials have been widely studied. Specifically, it is well known that light, heat and oxygen in the air seriously reduce the biological activity of functional materials. As such, there is a need to develop a new transdermal delivery system for stabilizing various active ingredients.

Researches about the synthesis and properties of a substance known as a metal-organic framework (MOF) have been actively conducted. The metal-organic framework is a three-dimensional crystalline porous material formed by coordination of a secondary structural unit containing a metal ion or a metal duster and an organic ligand. Up to now, thousands of metal-organic frameworks have been synthesized with the combination of metal secondary structural units and various organic ligand structures. Compared to conventional porous materials such as zeolite, activated carbon, silica and the like, the surface area of metal-organic frameworks is from 3 times to 7 times higher than that of conventional porous materials, and chemical functionalization is easier. As such, metal-organic frameworks have attracted attention as a new material to replace conventional porous materials.

MOF-5—which is a metal-organic framework synthesized by professor Omar M. Yaghi of the United States in 1999—is the first and representative metal-organic framework produced by coordinating between a 1,4-benzenedicarboxylic acid (BDC) organic ligand and a secondary structural unit of Zn4O. In the same year, the Williams research group in Hong Kong also synthesized a new form of metal-organic framework, HKUST-1, by the combination of 1,3,5-benzenetricarboxylic acid and secondary structural units of Cu2(COOR)4. In the case of HKUST-1, after synthesis, the solvent is coordinated to the Cu2+metal, and when it is heat-treated under vacuum, an open-metal site (OMS) is formed. As a result, it acts like a Lewis acid and can interact with electron-rich chemical species (Lewis base), thereby making it useful for catalysts, gas separation and storage.

The Yaghi research group in the United States, which synthesized MOF-5, designed and synthesized various MOFs modified from the first reported MOF-5 structure using organic synthesis technology. By adjusting the length of the organic ligand, MOFs having structures similar to MOF-5 but having an enlarged void size were synthesized. In addition, by using organic ligands having various functional groups, various functional groups were successfully introduced into the MOF structure. The tailor-made synthesis strategy—in which the desired properties can be controlled from the design stage—can be said to be a very unique advantage, making MOF materials different from other porous materials.

The Ferey research group in France has been researching Cr- and Fe-based carboxylate MOFs and synthesizing the MIL series, and MIL-53 (trade name: Basolite A100), a coordination compound of Al and benzenetricarboxylate (H3BTC) has been studied as a catalyst and adsorbent. In addition, MIL-101 has been reported as a porous material with a large surface area of up to 5,900 m2/g.

With the development of technologies in organic synthesis, organic ligands of various designs have been synthesized, and thousands of MOFs and various properties thereof have been reported by a combination of various metals and metal-clusters. The Hupp research group at Northwestern University in the United States has extended the length of organic ligands to synthesize a new form of MOF, Nu-110. A new ligand was designed through an experimental method and a computational chemical method, and Nu-110 was synthesized by reacting the new ligand with copper nitrate. The synthesized Nu-110 MOF has the largest surface area among the existing MOF materials, and its surface area is 7,100 m2/g, which is a huge surface area that can cover all of an American football field with 1 g of MOE This high surface area can serve as a great advantage when using MOF as a storage and separation of gases or as an energy storage. In the drug delivery system, it is a problem that the drug is rapidly decomposed before arriving at the target body tissue and its activity is lowered. Therefore, studies are being conducted to deliver drugs using a carrier to increase drug activity. In the case of using a carrier, it not only increases the stability of the drug, but also reduces the toxicity of the drug and increases the efficiency of the drug. As necessary conditions of the carrier for efficient drug delivery, a high loading amount, prevention of burst phenomenon and regulation of decomposition of the carrier are required. The nano-carriers reported to date include liposomes, nanoemulsions, nanoparticles, micelles, silica, etc., but these carriers did not meet the necessary conditions previously recited. According to the results of M. Vallet-Regi's research team, the storage capacity of the drug being loaded is reduced, especially in the case of silica, Therefore, MOF has been suggested as a solution to this problem. MOF is a material that combines the advantages of large pore volume, regular porosity and easy control of pore size. In this context, adjusting the pore structure and chemical functionality of the MOF can compensate for the shortcomings of currently used carriers, thereby realizing high drug loading, carrier-drug interactions and adequate release rates.

The Patricia Horcajada research team tried to apply the carrier as a carrier that can improve the drug-loading and carrier-drug interaction by adjusting the structure and porosity of the porous organo-metal structure. The research team used porous iron-carboxylate MOFs as nano-sized carriers to encapsulate drugs with different polarities, sizes and various functional groups. The iron-carboxylate MOFs used herein have advantages as carriers because they are non-toxic and biocompatible. In addition, the research team used water or ethanol instead of organic solvents in the process of immersing the MOFs in a solution in which each drug was dissolved to increase the potential for biomedical application.

Cellulose is a natural polymer composed of β(1-4) linkages of glucose, and does not exist independently as a single molecule in the plant cell wall, but exists as a layered hierarchical structure. Cellulose is the most abundant natural polymer material in nature and can be obtained mainly from wood and non-wood plant raw materials or synthesized through bacteria. In the case of wood, the cellulose content occupies about 40-55% of the total components, and by removing a significant amount of lignin and hemicellulose through a pulping process, it is possible to obtain pulp fibers which are of about 80% cellulose. Microfibers are formed through hydrogen bonding between cellulose chains, and several microfibers are bundled together to form macrofibers, from which fibers are formed. Cellulose has high strength, flexibility and strong hydrophilicity, and has properties such as biocompatibility and biodegradability, and thus has been studied and used in various fields such as paper and clothing.

Nanocellulose is a nano-structured cellulose. As nanotechnology began to draw attention in the scientific community, research on “cellulose nanofibers”—which are celluloses on a nanoscale—began to be actively conducted in the cellulose field. Cellulose nanofiber refers to a nano-level cellulose fiber having at least one dimension of less than 100 nm in the width or length of the fiber, and is generally manufactured by a chemical treatment method that is acid hydrolysis, a biological treatment method and a mechanical treatment method.

As a method of manufacturing cellulose nanofibers, cellulose nanofibers manufactured by a chemical treatment method through acid hydrolysis are called cellulose nanocrystals (CNC). Cellulose is composed of a crystalline region and a non-crystalline region. When the amorphous region is decomposed by acid treatment and a particle shape composed of the crystalline region is obtained, this is called cellulose nanocrystal. In general, this has disadvantages in that the manufacturing yield is very low and the manufacturing process including the acid removal process is complicated. Cellulose nanofibers produced by biological methods are also called bacterial celluloses because they are synthesized from bacteria such asAcetobacter xylinum. While a biological method has the advantage of obtaining high purity cellulose, it has the disadvantage that the production rate is very low. Cellulose nanofibers can be produced through mechanical processing such as high pressure homogenizing, microfluidizing and grinding. When a single fiber or a combination of several microfibers is obtained from cellulose fibers by mechanical treatment, these cellulose nanofibers are called cellulose nanofibrils (CNF).

Nanocellulose (cellulose nanocrystals [CNC] or cellulose nanofibrils [CNF]) has the potential to be applied to a very wide range of fields due to physical and chemical properties such as mechanical properties, film-forming properties, viscosity and high surface area.

SUMMARY

Technical Problem

Therefore, the technical problem of the present invention is the provision of a new composite for transdermal delivery which can efficiently deliver an active ingredient into the skin in a stable manner.

In addition, another technical problem of the present invention is the provision of a cosmetic composition comprising the composite for transdermal delivery.

Furthermore, still another technical problem of the present invention is the provision of a method for preparing the composite for transdermal delivery.

Solution to Problem

To solve the above technical problem, the present invention provides a composite for transdermal delivery comprising a metal-organic framework and nanocellulose.

In addition, the present invention provides a cosmetic composition comprising the composite for transdermal delivery.

Furthermore, the present invention provides a method for preparing a composite for transdermal delivery comprising: i) adding a nanocellulose solution to a metal-organic framework solution; ii) treating the solution obtained in step (i) by stirring or sonication to form a composite; and iii) drying the composite obtained in step (ii).

The present invention is described in detail hereinafter.

According to one aspect to the present invention, there is provided a composite for transdermal delivery comprising a metal-organic framework and nanocellulose.

In the present invention, as one ingredient of the composite for transdermal delivery, a metal-organic framework (MOF) is comprised.

A metal-organic framework is a three-dimensional crystalline porous material formed by coordination of a secondary structural unit containing a metal ion or a metal duster and an organic ligand. In the present invention, the metal-organic framework is preferably a zeolite imidazolate framework (ZIF). The zeolite imidazolate framework is composed of transition metal ion (e.g., Fe, Co, Cu or Zn) connected by an imidazolate linker.

In the present invention, the zeolite imidazolate framework is preferably ZIF-8. The ZIF-8 has a structure in which four (4) imidazoles are coordinated to zinc (Zn) ions (FIG. 1).

In the present invention, as one ingredient of the composite for transdermal delivery, nanocellulose is comprised. In the present invention, nanocellulose forms a composite with a metal-organic framework to improve the transdermal delivery effect and impart the stability to the transdermal delivery system.

In the present invention, preferably 0.01 to 20 parts by weight of the nanocellulose forms a composite, based on 10 parts by weight of the metal-organic framework. In one embodiment of the present invention, an imine group of the ZIF-8 is combined with the nanocellulose.

According to one embodiment of the present invention, the composite for transdermal delivery may further comprise an active ingredient. In the present invention, there is no special limitation according to an active ingredient. In the present invention, examples of an active ingredient include, but are not limited to, one or more selected from a moisturizer, a whitening agent, an anti-wrinkle agent, a UV blocking agent, a hair growth promoter, vitamin or a derivative thereof, amino acid or peptide, an anti-inflammatory agent, an acne therapeutic agent, a microbicide, female hormone, a keratolytic agent and a natural product. In addition, cosmetic ingredients such as oils, waxes, butters, paraffin, higher fatty acids such as stearic acid, esters such as cetyl ethylhexanoate, and silicones may also be used as an active ingredient.

Examples of moisturizer include, but are not limited to, creatine, polyglutamic acid, sodium lactate, hydroproline, 2-pyrrolidone-5-carboxyclic acid sodium salt, hyaluronic acid, sodium hyaluronate, ceramide, phytosteryl, cholesterol, sitosterol, pullulan and proteoglycan. Examples of whitening agent include, but are not limited to, arbutin and a derivative thereof, kojic acid, bisabolol, niacinamide, vitamin C and a derivative thereof, placenta and allantoin. Examples of anti-wrinkle agent include, but are not limited to, retinol, retinol derivative, adenosine, licorice extract, red ginseng extract and ginseng extract. Examples of UV blocking agent include, but are not limited to, benzophenone derivative, para-aminobenzoic acid derivative, methoxycinnamic acid derivative and salicylic acid derivative. There is no special limitation to a hair growth promoter, but it may be preferably a blood circulation promoter and/or a hair follicle stimulant. Examples of blood circulation promoter include, but are not limited to, the extract ofSwertia japonicaMakino, cepharanthin, vitamin E and a derivative thereof and gamma-oryzanol, and examples of hair follicle stimulant include, but are not limited to,capsicumtincture, ginger tincture, cantharides tincture and nicotinic acid benzyl ester. Examples of vitamin or a derivative thereof include, but are not limited to, vitamin A (retinol) and a derivative thereof, vitamin B1, vitamin B2, vitamin B6, vitamin E and derivatives thereof, vitamin D, vitamin H, vitamin K, pantothenic acid and derivatives thereof, biotin, panthenol, coenzyme Q10and idebenone. Examples of amino acid or peptide include, but are not limited to, cysteine, methionine, serine, lysine, tryptophan, amino acid extract, epidermal growth factor (EGF), insulin-like growth factor (IGF), fibroblast growth factor (FGF), copper tripeptide-1, tripeptide-29, tripeptide-1, acetyl hexapeptide-8, nicotinoyl tripeptide-35, hexapeptide-12, hexapeptide-9, palmitoyl pentapeptide-4, palmitoyl tetrapeptide-7, palmitoyl tripeptide-29, palmitoyl tripeptide-1, nonapeptide-7, tripeptide-10 citrulline, sh-polypeptide-15, palmitoyl tripeptide-5, diaminopropionoyl tripeptide-33 and r-spider polypeptide-1. Examples of anti-inflammatory agent include, but are not limited to, beta-glycyrrhetinic acid, glycyrrhetinic acid derivative, aminocaproic acid, hydrocortisone, β-glucan and licorice. Examples of acne therapeutic agent include, but are not limited to, estradiol, estrogen, ethinyl estradiol, triclosan and azelaic acid. Examples of microbicide include, but are not limited to, benzalkonium chloride, benzethonium chloride and halocalban. There is no special limitation to female hormone, but it may be preferably estrogen. As estrogen, it may be preferably estradiol, ethinyl estradiol or isoflavone which is a phytoestrogen. Examples of keratolytic agent include, but are not limited to, sulfur, salicylic acid, AHA, BHA and resorcin. Examples of the extract of natural product or an ingredient obtained therefrom include, but are not limited to, the extract of Japanese witch-hazel,Lamium albumvar. barbatum,Hedyotis diffuse, Rheum palmatum, licorice, aloe, chamomile, rose hip, horse chestnut, ginseng,Luffa aegyptiaca, cucumber, laver, sea mustard,Dioscorea batatas, snail and fruit ofDioscorea polystachya, or hinokitiol and beta-carotene. In addition, yeast extract, collagen, elastin,Centella asiaticaextract, aluminum sucrose octasulfate, DHA, EPA, flavor ingredient and the like may be used.

According to another aspect of the present invention, there is provided a cosmetic composition comprising the composite for transdermal delivery of the present invention. In the present invention, the cosmetic composition may be formulated to toner, lotion, body lotion, cream, essence and the like, but is not limited thereto.

The cosmetic composition comprises preferably 1 to 60% by weight, more preferably 2 to 50% by weight of the composite for transdermal delivery according to the present invention. In the present invention, if the cosmetic composition comprises the composite for transdermal delivery in an amount of less than 1% by weight, the effect according to an active ingredient may be weak, and if the amount of the composite for transdermal delivery is greater than 60% by weight, it may be economically undesirable since increasing the effect according to an active ingredient commensurately with the added amount would not be expected.

According to still another aspect of the present invention, there is provided a method for preparing a composite for transdermal delivery comprising: i) adding a nanocellulose solution to a metal-organic framework solution; ii) treating the solution obtained in step (i) by stirring or sonication to form a composite; and iii) drying the composite obtained in step (ii).

In step (i) of the preparation method, the metal-organic framework solution may be obtained by dissolving a metal-organic framework in a solvent—e.g., distilled water. The metal-organic framework is preferably a zeolite imidazolate framework (ZIF). In the present invention, the zeolite imidazolate framework is preferably ZIF-8.

In one embodiment of the present invention, ZIF-8 may be prepared by adding dropwise and stirring 2-methylimidazole solution to zinc nitrate hexahydrate solution.

In one embodiment of the present invention, the nanocellulose solution may comprise nanocellulose in a concentration of 5 to 20% by weight.

In step (ii) of the preparation method, when the solution obtained by adding the nanocellulose solution to the metal-organic framework solution is treated by stirring or sonication, the nanocellulose and the metal-organic framework are combined to form a composite. In one embodiment of the present invention, an imine group of the ZIF-8 is combined with the nanocellulose.

In step (iii) of the preparation method, drying of the prepared composite may be carried out, for example, by high-temperature vacuum drying at 60° C. or higher, or freeze-drying. In one embodiment of the present invention, after the drying of the step (iii), a step of washing the prepared composite may be further carried out. The washing of the composite may be carried out, for example, by the use of ethanol.

Effects of the Invention

A composite for transdermal delivery according to the present invention can show excellent efficacy even with a small amount of an active ingredient for a long time by efficiently transferring an active ingredient into the skin in a very stable form.

