Silicic-acid-releasing fibres or fibre fragments, fibre non-wovens produced herefrom, and formulation
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
- Filing Date
- 2024-08-20
- Publication Date
- 2026-07-01
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Abstract
Description
[0001] Silica-releasing fiber or fiber fragments, fiber lye made therefrom and formulation
[0002] The present invention relates to silica-releasing fibers or fiber fragments formed by producing a spinnable sol by hydrolytic condensation of at least one silane compound selected from the group consisting of tetraalkoxysilanes, trialkoxysilanes, halosilanes, and mixtures thereof, catalyzed with an organic or inorganic acid having a pKa value of <2.5, followed by spinning the spinnable sol into a fiber. The fibers or fiber fragments are infiltrated by contacting the spun fiber or fiber fragments with a non-aqueous solution. The invention also relates to nonwoven fabrics containing these silica-releasing fibers or fiber fragments.These fibers, fiber fragments, or fiber nonwovens are used in the fields of regenerative therapies, microbiology, pharmaceutical applications, the cosmetics industry, diagnostics, the food industry, filters, fiber reinforcement of materials, and optics.
[0003] For the topical application of active ingredients in the skin area (skin diseases, scar reduction, minor burns, acne, cosmetics, etc.), carrier systems are required that simultaneously demonstrate a design that can be individually adapted to the application site, a (time-adjustable) active ingredient release and a subsequent dissolution behavior that is as complete and skin-compatible as possible.
[0004] Cosmetically active substances are applied, for example, via face masks to trigger an anti-aging or well-aging effect on or in the skin. The face masks used are usually made of cellulose (derivatives), proteins or synthetic polymers such as silicones, and apply cosmetically active substances to the skin superficially. All of these face masks have to be removed from the skin after use and therefore produce waste. In the interests of effectiveness and sustainability, a new generation of face masks or pads has been developed. These should have the following property profile: a) The face mask should have a lasting cosmetic effect. b) The face mask should dissolve completely or largely on the skin and its degradation products should be absorbed into the skin. Any remaining residues degrade when the skin is washed off.This leaves no residue from the face mask that needs to be disposed of. c) The face mask should dissolve completely into naturally occurring components. The only water-soluble form of silica, orthosilicic acid (OSA), shows, among other things, the potential to stimulate collagen production and thus the formation of connective tissue in the dermis. A low content of silicic acid (OSA) in the dermis is linked to blood counts. For example, it has been observed, particularly in older people, that the natural Si content in the blood serum decreases, which in turn is reflected in the skin's appearance (E. Bisse, Analytical Biochemistry 337 (2005) 130-135).
[0005] The connective tissue-stimulating effect of silicas is also intended for use in cosmetics. However, transdermal administration presents a major challenge. Many condensed silicas or amorphous forms of silica exhibit a very low dissolution rate (release of water-soluble orthosilicic acid), so they currently have little or no application for transdermal administration.
[0006] In addition, orthosilicic acid is said to have a positive effect on hair, strengthen nails, is involved in bone formation and, according to recent findings, can even be an important component in the prevention of Alzheimer's disease.
[0007] State-of-the-art cosmetic silica products are based on bamboo silica and are usually sold as dietary supplements with advertised cosmetic effects or as a powder for application to the skin. Polysilicic acids such as bamboo-based silica have been scientifically proven not to be absorbed by healthy skin and integrated into the metabolism (LA de Araüjo et al., A. brasil. dermat. 2016, 91, 331).
[0008] Another state-of-the-art approach is to offer ortho-silicic acid in the form of a tincture. Ortho-silicic acid is only slightly soluble in aqueous solutions at approximately 120 mg / l. Higher concentrations of ortho-silicic acid cannot therefore be offered in tinctures. In available liquid tinctures, ortho-silicic acid remains in solution throughout the entire storage period, which can lead to intermolecular condensation, i.e., the formation of polysilicic acids. Competitors attempt to avoid this condensation by using synthetic molecules as ortho-silicic acid substitutes. One example is monomethylsilanetriol or maltodextrin-stabilized oKS (Anderson Oliveira Ferreira et al., Cosmetics 2018, 5, 41). In monomethylsilanetriol, a silanol group (-Si-OH) in ortho-silicic acid is replaced by a methyl group (Si-CHs). This modification is classified as unnatural since Si-C bonds do not occur in nature.
[0009] One publication mentions that ortho-silicic acid can be stabilized with hydrolyzed marine collagen. This was administered in capsule form so that it can be ingested orally, and the test subjects' skin texture, hydration, and firmness appeared to improve (Petersen Vitello Kalil CL et al., Evaluation of cutaneous rejuvenation associated with the use of ortho-silicic acid stabilized by hydrolyzed marine collagen. J Cosmet Dermatol. 2018;17:814-820).
[0010] Established face masks on the market are mostly sheet masks that must be removed after use, thus producing waste. These have no connection to the administration of orthosilicic acid through the skin barrier. Gel masks also exist, which gel after application and must also be removed afterwards.
[0011] A nonwoven face mask that is completely absorbed into the skin, thus producing no waste, and also transports silica into / through the skin, does not exist either on the market or in specialist literature.
[0012] Based on this, it was the object of the present invention to provide fibers or fiber fragments as well as nonwovens and formulations containing them, which allow dermal application and enable the transport of silica into or through the skin.
[0013] This object is achieved with the fibers or fiber fragments having the features of claim 1, the fiber fleeces having the features of claim 11, and the cosmetic agent having the features of claim 17. The further dependent claims show advantageous developments.
[0014] A "biodegradable" fiber in the sense of the present invention means a fiber that is cytocompatible and degrades under physiological conditions.
[0015] Silicas are compounds of the general formula H(2n+2)Si n O(3n+i), such as monosilicic acid (Si(OH)4 or l-SiC), disilicic acid (HeSiOe), trisilicic acids (HsSiOs), other oligosilicic acids, polysilicic acids and cyclic (poly)silicic acids.
[0016] In the context of the present invention, the term "viscosity" means the dynamic viscosity, which is preferably measured using an Anton Paar rheometer of the type Physica MCR301 with a coaxial cylinder measuring attachment of the type CC17 / T200 / SS and a shear rate of 10 s 1 is determined.
[0017] The "crosslinking of the silane compound" and the covalent incorporation of an organic acid into the network is illustrated in the following scheme using the incorporation of methanesulfonic acid.
[0018] According to the invention, silica-releasing fibers or fiber fragments are provided, which are formed by producing a spinnable sol by hydrolytic condensation of at least one silane compound selected from the group consisting of tetraalkoxysilanes, trialkoxysilanes, halosilanes, and mixtures thereof, wherein the hydrolytic condensation is catalyzed by an organic acid with a pKa value of <2.5, and subsequently spinning the spinnable sol into a fiber. The pKa should be below the isoelectric point.
[0019] The invention is characterized in that the fiber is infiltrated by bringing the spun fiber or fiber fragments into contact with a non-aqueous solution and with the non-aqueous solution.
[0020] Preferably, contacting the non-aqueous solution is carried out by spinning the fiber into the non-aqueous solution as a spin bath. Alternatively, and equally preferably, this can also be done by spraying or sprinkling the spun fiber or fiber fragments with the non-aqueous solution, or by placing the spun fiber or fiber fragments in the non-aqueous solution.
[0021] In the context of the present invention, non-aqueous solution is understood to mean a non-aqueous solvent or a mixture of several non-aqueous solvents.
[0022] It is preferred that the non-aqueous solution is selected from the group consisting of vegetable oils, mineral oils, glycerin, propylene glycol and its derivatives, esterified glycerins, polyethylene glycols, fatty acid esters, fatty acids, fatty alcohols, wax alcohols, waxes, resins, glucosides, terpenes, squalenes, phospholipids, ceramides and mixtures thereof, preferably selected from the group consisting of sunflower oil, almond oil, jojoba oil, avocado oil, passion fruit oils, moringa oil, butylene glycol cocoate, MIPA laureth sulfate (and) cocoamidopropyl betaine, dicaprylyl ester (and) decyl glucosides (and) glyceryl oleate, ethyl hexyl stearate, cetearyl isononanoate, capryl caprylate, dicaprylyl caprate, octyldodecanol, phytosqualane, dimethicone, isopropyl myris- tat, isopropyl palmitate, liquid paraffin, linoleic acid, propylene glycol, butylene glycol, limonene and mixtures thereof.
[0023] Particularly preferably, the non-aqueous solution is selected from the group consisting of sunflower oil, almond oil, jojoba oil, avocado oil, moringa oil, passion fruit oils, butylene glycol cocoate, MIPA laureth sulfate (and) cocoamidopropyl betaine, dicaprylyl ester (and) decyl glucoside (and) glyceryl oleate, ethylhexyl stearate, cetearyl isononanoate, capryl caprylate, dicaprylyl caprate, octyldodecanol, phytosqualane, dimethicone, isopropyl myristate, isopropyl palmitate, paraffin oil, linoleic acid, linoleic acid, propylene glycol, butylene glycol, limonene and mixtures thereof.
[0024] The non-aqueous solution does not contain any short-chain alcohols, in particular no Ci-C4 alcohols such as methanol, ethanol, propanols and butanols.
[0025] Further cosmetically or pharmaceutically active substances may preferably be dissolved or dispersed in the non-aqueous solution.
[0026] The non-aqueous solution is preferably in the liquid state at temperatures in the range of -20 to +80°C, particularly preferably at +15 to +40°C, i.e. the solution has a viscosity in the range of 0.5 to 10,000 mPas at 20°C. However, applications are also conceivable in which the non-aqueous matrix only becomes liquid at room temperature, body temperature, or slight heat exposure or another external trigger, such as shear forces or ultrasound.
[0027] It is further preferred that the at least one organic or inorganic acid is selected from the group consisting of nitric acid, hydrochloric acid, sulfuric acid, sulfonic acids, in particular methanesulfonic acid, carboxylic acids, carboxylic acid esters, sulfuric acid esters, amino acids, phosphonic acids, phosphoric acid esters, and mixtures thereof or mixtures thereof with other acids having a pKa value in the range of >= 2.5 to 7.0. Particular preference is given to using methanesulfonic acid.
[0028] A preferred embodiment provides that the at least one silane compound is selected from the group consisting of mixed or unmixed tetraalkoxysilanes according to the general formula Si(OC x H2x+i)4 with x = 1-12, preferably selected from the group consisting of tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane and mixtures thereof.
[0029] The fiber thicknesses preferably range from 50 nm to 120 pm, particularly preferably from 30 to 70 pm. Pure silica gel fibers, but also fibers in which cosmetically or pharmaceutically active substances are incorporated into the fiber matrix, can be used as fibers.
[0030] It is preferred that the fiber can be produced using a process comprising the following steps: a) providing an alcoholic solution of at least one silane compound selected from the group consisting of tetraalkoxysilanes, trialkoxysilanes, halosilanes and mixtures thereof, wherein the alcohol is preferably selected from the group consisting of monohydric, dihydric or trihydric, branched or unbranched alcohols, which can be aliphatic or aromatic and which is particularly preferably selected from the group consisting of ethanol, propanol, butanol, ethylene glycol, phenol and mixtures thereof; b) providing an aqueous solution of at least one organic or inorganic acid with a pKa value of < 2.5, wherein the organic acid is preferably 0.01 N to 1 N and / or wherein the content of organic acid in the aqueous solution is preferably in the range from 0.01 to 2% by weight, preferably 0.05 to 1% by weight.-% and particularly preferably 0.1 to 0.5 wt.%, based on the total weight of the solution; c) mixing the solutions provided in steps a) and b) and mixing for 4 hours to 1 week at a temperature of 20 to 70°C; d) removing at least part of the alcohol from the mixture from step c) and then cooling the concentrated mixture to a temperature of 20 to -25°C; e) storing the cooled mixture from step d) until a viscosity of 10 to 75 Pa-s is reached; f) spinning the mixture from step e) into continuous fibers, wherein during steps c) to f) crosslinking of the silane compound takes place and at least part of the organic or inorganic acid is incorporated into the resulting network and / or contributes to the crosslinking.
[0031] A further preferred embodiment of the present invention provides that the mixing in step c) is carried out by dropwise addition of the aqueous solution of the organic or inorganic acid to the alcoholic silane solution or the mixing in step c) is carried out by dropwise addition of the alcoholic silane solution to the aqueous solution of the organic or inorganic acid or the mixing in step c) is carried out by simultaneous combination of the alcoholic silane solution and the aqueous solution of the organic or inorganic acid.
[0032] According to a further preferred embodiment of the present invention, the mixing according to step c) is carried out by stirring or shaking.
[0033] According to a further preferred embodiment of the present invention, the mixture from step c) is stirred for 10 minutes to 168 hours, preferably 10 to 24 hours, and particularly preferably 16 to 18 hours. Another preferred embodiment of the present invention provides that the temperature in step c) is 4 to 70°C, preferably 10 to 50°C, and particularly preferably 25 to 40°C.
[0034] According to a further preferred embodiment of the present invention, the pH of the mixture in step c) is < 5.5, preferably 1 to 5 and particularly preferably 2 to 4.
[0035] A further preferred embodiment of the present invention provides that the mixing in step c) takes place by dropwise addition of the aqueous solution of the organic or inorganic acid to the alcoholic silane solution or the mixing in step c) takes place by dropwise addition of the alcoholic silane solution to the aqueous solution of the organic or inorganic acid or the mixing in step c) takes place by simultaneously combining the alcoholic silane solution and the aqueous solution of the organic or inorganic acid and the mixing according to step c) takes place by stirring and the mixture from step c) is stirred for 10 minutes to 144 hours, preferably 10 to 24 hours and particularly preferably for 16 to 18 hours and the temperature in step c) is 4 to 70°C, preferably 10 to 50°C and particularly preferably 25 to 40°C and the pH of the mixture in step c) is < 5, preferably 1 to 4.9 and particularly preferably 2 to 4.9.
[0036] According to another preferred embodiment of the present invention, during step d) 40 to 80 wt.%, preferably 45 to 75 wt.% and particularly preferably 50 to 65 wt.% of the solvent mixture, based on the total mass of the batch provided in step b), is removed.
[0037] According to a further preferred embodiment of the present invention, the concentrated mixture from step d) is cooled to a temperature of 20 to -25°C, preferably 10 to -25°C and particularly preferably 4 to -20°C.
[0038] A further preferred embodiment provides that during step d) at least part of the water from step b) is also removed.
[0039] According to a further preferred embodiment of the present invention, during step d) 40 to 80 wt.%, preferably 45 to 75 wt.% and particularly preferably 50 to 65 wt.% of the solvent mixture, based on the total mass of the batch provided in step b), is removed and the concentrated mixture from step d) is cooled to a temperature of 20 to -25°C, preferably 10 to -25°C and particularly preferably 4 to -20°C, and at least part of the water from step b) is removed.
[0040] According to a further preferred embodiment of the present invention, step e) is carried out until a viscosity of 10 to 70 Pa-s, preferably 10 to 40 Pa-s and particularly preferably 20 to 25 Pa-s is reached.
[0041] It is preferred that the spinning is carried out by electrospinning, preferably with the addition of a spinning aid and at a voltage of 1 to 30 kV and at a distance of 0.2 to 30 cm, particularly preferably at a voltage of 6 to 30 kV and at a distance of 10 to 30 cm or a voltage of 1 to 5 kV and at a distance of 0.2 to 2 cm, or pressure spinning, preferably at a pressure of 10 to 60 bar, particularly preferably 20 to 40 bar.
[0042] A further preferred embodiment of the present invention provides that the process includes the following further process steps, which take place after step f): g) comminuting, cutting or punching the continuous fibers obtained after spinning in step f), and / or h) sterilizing the fibers from step f) or g), preferably by y-radiation or by autowashing, treatment with ethylene oxide, hydrogen peroxide, a 70% ethanol solution or chloroform.
[0043] During steps c) to f) of the manufacturing process, a pre-crosslinking of the silane compounds takes place, which progresses steadily over time and crosslinks the fiber matrix. If the fiber or fiber fragment is brought into contact with a non-aqueous liquid after step f) or g) or h), this liquid can infiltrate into the fibers or fiber fragments. The non-aqueous liquid prevents further condensation (crosslinking) to form a dense inorganic network. Instead, only silica clusters with a low degree of crosslinking are present, which are additionally stabilized in the form of a fiber through intramolecular interactions with the non-aqueous liquid. Through the mechanical action during massage into the skin, silica clusters and silicic acids are released and absorbed into the skin (Fig. 3). Through the initial contact with water, e.g.Sweat or other bodily fluids hydrolyze the silica clusters into silicic acids. This hydrolysis reaction can be accelerated by bringing an aqueous solution into contact with the ground fibers or fiber fragments.
[0044] According to a further preferred embodiment of the present invention, the process is carried out continuously or batchwise.
[0045] According to another preferred embodiment of the present invention, the method contains no other process steps than the above-mentioned steps a) to h) and the infiltration with the non-aqueous solution. The invention also provides a nonwoven fabric that contains or consists of the previously described silica-releasing fibers or fiber fragments.
[0046] Such non-woven fabrics can be massaged into the skin within a few seconds to minutes without leaving any residue, i.e. the fibers are completely absorbed by the skin or transported across the epidermis.
[0047] The thickness of the fiber webs is adjustable and is preferably in the range from 100 pm to 10 mm, particularly preferably from 400 pm to 2 mm.
[0048] It is preferred that the aqueous solution has a pH of preferably 3.7 to 9.0, particularly preferably 4.7 to 7.5. The dissolution of the fibers is accelerated the more alkaline the solution is.
[0049] Furthermore, it is preferred that the aqueous solution contains further additives selected from the group consisting of
[0050] • surface-active substances, especially ionic and non-ionic surfactants, saponins, fatty acids, phospholipids, ceramides,
[0051] • Penetration enhancers, especially phospholipids, polyethylene glycols,
[0052] • contains cosmetically active additives, in particular vitamins, provitamins, amino acids, heparin, hyaluronic acids, collagen (derivatives), plant extracts, probiotics, enzymes, hydrating substances, fragrances, dyes, preservatives, abrasive substances / particles.
[0053] The absorption of silica into the skin can also be improved by using transport enhancers such as (unsaturated) phospholides or polyethylene glycols, or by reducing the skin barrier through physical or chemical stimuli, e.g., ultrasound, microabrasion, transport enhancers, etc. The invention has the following advantages:
[0054] 1) Effective transdermal administration of ortho-silica:
[0055] Silica gel fiber fleeces are an amorphous, fibrous solid that stores silica precursors in condensed form (silica gel). Upon contact with water (surfactant solution and, surprisingly, also by massaging without an aqueous solution), the fiber fleece dissolves and is completely absorbed by the skin. This allows large amounts of silica (depending on the weight of the fleece and the applied skin area) to be applied, resulting in an orthosilica effect in vivo.
[0056] Topical competitors use balms / creams or aqueous tinctures, but these deliver only smaller amounts of orthosilicic acid. Alternatives include dietary supplements for oral administration. If orthosilicic acid does cross the intestinal barrier at all, it is more likely to be administered systemically rather than locally into the skin.
[0057] Methylated silica is also used in the literature because it is stable in aqueous solutions and exhibits little self-condensation. This modification contains a Si-C bond, which does not occur naturally.
[0058] This releases unnatural substances into the environment. According to our research, there is currently no orthosilica-releasing face mask on the market.
[0059] 2) Reduction of waste (and microplastics):
[0060] Nearly all face masks on the market consist of a support structure that is applied to the skin and removed after cosmetic use. This creates household waste with each use. These face masks are often made of cellulose or synthetic materials such as silicones. Our invention is completely absorbed into the skin, leaving no waste behind. Starting with the silica gel fibers, only naturally occurring silica is produced.
[0061] It is also possible to produce the face mask completely free of (micro)plastics. This is the case if the water-free liquid is also made of a natural or near-natural substance.
[0062] The fibers, fiber fragments and fiber fleeces are used in the following application fields: a) Cosmetics (for humans and animals):
[0063] • Silica-releasing pad for topical application, especially on skin, e.g. face mask, eye pads, forehead mask, scalp, nail bed, acne, scars
[0064] • Oil-impregnated nonwoven pieces / individual fibers / fiber fragments for formulation in lotions, ointments, creams (including toothpaste), shower gels
[0065] • Silica-releasing dressing for topical application to reduce connective tissue weaknesses, e.g. cellulite, or scar formation / reduction
[0066] • Reduction of germs by applying oil-soaked fleece (antibacterial effect of the water-free liquid) b) Food supplement and food additive (for humans and animals):
[0067] • KS-releasing nonwoven fabric or individual fibers soaked in (edible) oils / liquids for oral ingestion c) Pharmacy (for humans and animals):
[0068] • KS-releasing fiber fleeces / fleece pieces / individual fibers / fiber fragments for therapy or symptom relief in inflammatory and / or chronic skin diseases, acne, age spots, neurodermatitis, decubitus, eczema, keratoses, psoriasis, dry skin, cellulitis, cellulite or
[0069] • as insect repellent
[0070] • for skin irritations
[0071] • for superficial burns
[0072] • to support the treatment of skin diseases for the regenerative formation of healthy skin
[0073] • antibacterial effect through KS-releasing fibers, which are applied in a water-free liquid Strengthening of the connective tissue
[0074] Strengthening of blood vessel walls; reduction of bruises in people with weakened vessel walls d) Plants:
[0075] • KS reservoir in culture and regeneration of plants
[0076] • for plant protection
[0077] According to the invention, a cosmetic agent is also provided which provides fibers or fiber fragments or fiber nonwovens as previously described.
[0078] These cosmetic products are preferably in the form of creams, emulsions, lotions, gels and oils for skin care, face masks, make-up bases (liquids, pastes, powders), face powders, body powders, foot powders, toilet soaps, deodorant soaps, perfumes, toilet waters and colognes, bath and shower additives (salt, foam, oil, gel), hair removal products, deodorants and antiperspirant products, hair colorants, hair waving, straightening and styling products, hair setting products, hair cleaning products (lotions, powders, shampoos), hair care products (lotions, creams, oils), styling aids (lotions, varnish, brilliantine), shaving products (including pre- and after-treatment products), make-up and make-up removers, lip care products and cosmetics, dental and oral care products, nail care products and cosmetics, products for external intimate care, sunscreen products, self-tanning products, Skin bleaching agents, anti-wrinkle products.
[0079] The subject matter of the invention will be explained in more detail with reference to the following figures and examples, without wishing to restrict it to the specific embodiments shown here.
[0080] Fig. 1 shows a diagram of the results from an ICP analysis of the basolateral medium of a transport study on an in vitro epidermis model.
[0081] Fig. 2 shows cross sections of epidermis models in comparison between the inventive and untreated models. Fig. 3 shows photos after application of a nonwoven fabric according to the invention on human skin.
[0082] Example 1
[0083] 5 mol of tetraethoxysilane (Sigma Aldrich) were mixed in ethanolic solution (230 ml). 163.5 g of a 0.1 N methanesulfonic acid solution were added dropwise to this sol over 2 h, and the resulting mixture was stirred for a further 18 h at 40°C. The solvent was then removed from the sol until a residual mass of 577 g of sol remained in the flask. The sol was matured at -20°C until it reached a honey-like viscosity (21 Pas measured at 4°C). The viscous liquid was filled into a pressure vessel maintained at -15°C and pressed at a pressure of 20 bar through a nozzle plate with seven nozzles (nozzle diameter: 150 μm). After a drop of 2.5 m, the p-fibers were collected at an air humidity of 20% on a traversing table movable in the x and y directions to form a nonwoven.A container filled with sunflower oil was placed on the traversing table, allowing the individual filaments to be deposited directly in the sunflower oil, forming a fleece. The fleece was removed, cut to size, and massaged into the skin without leaving any residue.
[0084] Example 2
[0085] The silica-releasing fibers were prepared as in Example 1 and also applied to the skin and massaged in. The skin was then additionally treated with micellar water or an aqueous surfactant solution.
[0086] Example 3
[0087] 5 mol of tetraethoxysilane (Sigma Aldrich) were mixed in ethanolic solution (250 ml). 176.4 g of a 0.1 N nitric acid solution were added dropwise to this sol over a period of 2 h, and the resulting mixture was stirred for a further 18 h at 40°C. The solvent was then removed from the sol until a residual mass of 616.2 g of sol remained in the flask. The sol was matured at -20°C until it reached a honey-like viscosity (32 Pas measured at 4°C). The viscous liquid was poured into a pressure vessel maintained at -15°C and forced at a pressure of 20 bar through a nozzle plate with 19 nozzles (nozzle diameter: 150 μm). After a drop of 2.5 m, the fibers were collected and processed into a nonwoven fabric at an air humidity of 20% on a traversing table movable in the x and y directions.A container filled with sunflower oil was placed on the traversing table, allowing the individual filaments to be deposited directly in the sunflower oil and form a fleece. The fleece was removed, cut to size, and massaged into the skin without leaving any residue.
[0088] Example 4
[0089] The silica-releasing fibers were produced as in Example 3, except that the fibers were spun using 0.1 N methanesulfonic acid as a catalyst and infiltrated with sunflower oil. Infiltration was carried out in five different ways:
[0090] 1) The nonwoven fabric was coated with sunflower oil.
[0091] 2) The nonwoven fabric is placed in a package filled with sunflower oil.
[0092] 3) The nonwoven fabric was sprinkled with sunflower oil using a pipette.
[0093] 4) The nonwoven fabric was sprayed with sunflower oil from a pump spray.
[0094] 5) The nonwoven fabric was finely sprayed with sunflower oil using an airbrush system.
[0095] Example 5
[0096] The silica-releasing fibers were produced as in Example 3, except that the fibers were spun using 0.1 N HCl as a catalyst and infiltrated with sunflower oil as in Example 4.
[0097] Example 6
[0098] Silica gel p-fibers were pressure-spun as in Example 1 using methanesulfonic acid as a catalyst and spun into a nonwoven fabric using a traversing table movable in the x- and y-directions. After spinning, the p-fibers were sprayed with non-aqueous solutions within less than 10 minutes. After cutting, the nonwoven fabric can be massaged completely into the skin.
[0099] Example 7
[0100] Silica gel p-fibers were pressure-spun as in Example 1 using methanesulfonic acid as a catalyst and spun into a nonwoven fabric using a traversing table movable in the x- and y-directions. During spinning, the fibers were sprayed with non-aqueous liquids. After cutting, the nonwoven fabric can be massaged completely into the skin.
[0101] Example 8
[0102] Silica gel p-fibers are pressure-spun using methanesulfonic acid as a catalyst, as described in Example 1, and then spun into a nonwoven fabric using a traversing table that moves in the x- and y-directions. The nonwovens are cut to size and then sprinkled with non-aqueous liquids and mixtures thereof. The nonwovens can be massaged completely into the skin.
[0103] The following substances and mixtures thereof were tested as non-aqueous liquids:
[0104] Sunflower oil, almond oil, jojoba oil, moringa oil, avocado oil, Cegesoft PFO (passion fruit oils), Cocoate BG, Lumorol K1056 (MIPA Laureth Sulfate (and) Cocoamidopropyl Betaine), Plantasil Micro (Dicaprylyl ester (and) decyl glucoside (and) glyceryl oleate), Cetiol 868 (Ethylhexyl Stearate), Cetiol SN (Cetearyl Isononanoate), Cetiol RLF (Capryl Caprylate), Cetiol CC (Dicaprylyl Caprate) Eutanol G (Octyldodecanol), Phytosqualane, Abil350 (Dimethiocone), Isopropyl Myristate, Isopropyl Palmitate, Linoleic Acid, Propylene Glycol, Butylene Glycol, Paraffin Oil.
[0105] Example 9
[0106] 5 mol of tetraethoxysilane (Sigma Aldrich) were mixed in ethanolic solution (230 ml). 163.5 g of a 0.1 N methanesulfonic acid solution were added dropwise to this sol over 2 h, and the resulting mixture was stirred for a further 18 h at 40°C. The solvent was then removed from the sol until a residual mass of 577 g of sol remained in the flask. The sol was matured at -20°C until a honey-like viscosity (21 Pas measured at 4°C) was reached. The viscous sol was then warmed to 4°C and directly treated with 577 g of a mixture of 571 g of ethanol and 6 g of polyethylene glycol (M w = 50000 g / mol).
[0107] With a distance of 15 cm between the cannula and the rotating target, the spinning process takes place at a flow rate of 0.7 ml / h and an applied voltage of 13-16 kV to the cannula. The resulting fiber webs consist of fibers with a diameter of approximately 1 pm. The resulting webs are cut to size and then sprinkled or sprayed with non-aqueous liquids and mixtures thereof. These fiber webs can be massaged completely into the skin.
[0108] Example 10
[0109] Application of impregnated silica gel fibers to 3D in vitro epidermis models
[0110] Experimental procedure: For testing, epidermal in vitro epidermis models were constructed from primary cells (keratinocytes) in the Tran swell system.
[0111] A total of two silica gel (KG) fiber samples were prepared according to Example 1. Sample 1 was infiltrated with sunflower oil (SB) (Sample 1 = KG+SB); Sample 2 with isononanoic acid alkyl esters (INSA) (Sample 2 = KG+INSA).
[0112] Each sample - KG+SB and KG+SB - was massaged into three different epidermis models, then PBS (physiological phosphate buffer) was added to the model and cultured for another 24 h in the incubator.
[0113] An epidermis model without silica gel fibers was used as a control. (SB and INSA alone showed no cytotoxicity on the epidermis model in preliminary experiments.)
[0114] After the experiment was stopped, the structure of the skin model was checked using hematoxylin-eosin (H / E) staining, cell viability was evaluated using an MTT test, and the concentration of oKS transported through the skin was quantified using an ICP analysis.
[0115] Evaluation of the results:
[0116] Both the KG+SB and KG+INSA samples performed well. Cross-sections of the models, after H / E staining, showed a physiological epidermal structure without any abnormalities regarding cytotoxic effects, even after application of both samples. The epidermal layer remains intact and closed even after application of both samples. Cell viability determination via the MTT test, with values of >70% compared to the negative control, shows no cytotoxic properties. The slight reduction in cell viability is due to the mechanical impact during massage on the epidermis model, which is only approximately 200-300 μm thick. The TEER value of the epidermis models decreased from 12,000 ohm*cm in all three samples compared to the untreated control. 2 to 5,000 - 6,000 Ohm*cm 2. ie, the barrier function of the epidermis is still present, but reduced. This may be due to swelling of the skin by the lipophilic substances and the aqueous solution and may even facilitate the necessary oCS transport through the skin.
[0117] In both samples (KG+SB and KG+INSA), the transport of orthosilicic acid through the epidermis could also be monitored via ICP analysis. The skin models were cultured in a so-called "transwell" setup with two compartments. The epidermis model forms the interface between the two compartments. Compartment 1 represents the interface between the epidermis and the air. The nonwoven fabric was applied to the model and massaged into this compartment. The second compartment is filled with cell culture medium and supplies the cells with nutrients. If transport of silica through the epidermis model has occurred, silicon (Si) should be detectable in the cell culture medium from compartment 2 via ICP analysis.
[0118] In both cases, ICP analyses show transported Si concentrations of 1.7–2.5 pg / mL. This corresponds to an orthosilicic acid concentration (Si(OH)4) of 5.8–8.6 pg / mL. The Si concentration in the blood plasma of 18–29 year-olds is approximately 0.3 pg / mL and decreases with age (> 50 years) to as low as 0.2 pg / mL (Analytical Biochemistry 337 (2005) 130–135).
[0119] Compared to physiological Si concentrations, the detected Si transport exceeds these physiological values. Considering that the transported oKS is further diluted in vivo by tissue fluid and blood, the determined values are at a promising concentration for the postulated anti-aging effect.
[0120] Fig. 1 shows the results obtained. Silica gel fiber fleeces soaked in SB and INSA were applied. A model to which only pure buffer solution was applied served as a reference. The experiments were conducted in triplicate. > 1 mg / l of oKS could be transported through the epidermis of the in vitro model.
[0121] Fig. 2 shows a microscopic image of a hematoxylin-eosin stain on cross-sections of paraffin-embedded in vitro epidermis models. One model served as a reference and was treated only with pure PBS. Two additional models were exposed to silica gel fibers infiltrated with sunflower oil (SB) and isononanoic acid alkyl esters (INSA) prior to embedding and hematoxylin-eosin staining, and then post-treated with PBS. All models exhibit an intact skin barrier even after contact with the infiltrated fibers.
[0122] Figure 3 illustrates the application of a nonwoven fabric according to the invention. A nonwoven fabric according to the invention, which was sprinkled with sunflower oil immediately after spinning, was applied to human skin (A). By mechanically rubbing the nonwoven fabric onto the skin, the nonwoven fabric is completely absorbed by the skin (B). Afterward, no fiber residue remains on the skin (C).
Claims
Patent claims 1. Silica-releasing fiber or fiber fragments formed by producing a spinnable sol by hydrolytic condensation of at least one silane compound selected from the group consisting of tetraalkoxysilanes, trialkoxysilanes, halosilanes and mixtures thereof, which is catalyzed with at least one organic or inorganic acid with a pKa value of < 2.5 and then spinning the spinnable sol into a fiber, characterized in that the fiber is infiltrated by contacting the spun fiber or fiber fragments with a non-aqueous solution.
2. Fiber or fiber fragments according to claim 1, characterized in that the contacting of the non-aqueous solution is carried out by spinning the fiber into the non-aqueous solution as a spinning bath or by spraying or sprinkling the spun fiber or fiber fragments with the non-aqueous solution or by placing the spun fiber or fiber fragments in the non-aqueous solution.
3. Fiber or fiber fragment according to one of claims 1 or 2, characterized in that the non-aqueous solution is selected from the group consisting of vegetable oils, mineral oils, glycerin, propylene glycol and its derivatives, esterified glycerols, polyethylene glycols, fatty acid esters, fatty acids, fatty alcohols, wax alcohols, waxes, resins, glucosides, terpenes, squalenes, phospholipids, ceramides and mixtures thereof, preferably selected from the group consisting of sunflower oil, almond oil, jojoba oil, avocado oil, passion fruit oils, moringa oil, butylene glycol cocoate, MIPA laureth sulfate (and) Cocoamidopropyl Betaine, Dicaprylyl Esters (and) Decyl Glucosides (and) Glyceryl Oleate, Ethylhexyl Stearate, Cetearyl Isononanoate, Capryl Caprylate, Dicaprylyl Caprate, Octyldodecanol, Phytosqualane, Dimethicone, Isopropyl Myristate, Isopropyl Palmitate, Liquid Paraffin, Linoleic Acid, Propylene Glycol, Butylene Glycol, Terpenes and mixtures thereof.
4. Fiber or fiber fragment according to one of claims 1 to 3, characterized in that the non-aqueous solution contains at least one further substance selected from the group consisting of cosmetic base substances, active ingredients, additives, auxiliaries and combinations thereof, preferably selected from the group consisting of spreading agents, penetration enhancers, waxes, vitamins, in particular fat-soluble vitamins, fragrances, hydrating substances, dyes, plasticizers, light stabilizers, emulsifiers, antioxidants, radical scavengers and preservatives and combinations thereof, wherein the at least one further substance is preferably present in pure or encapsulated form.
5. Fiber or fiber fragment according to one of claims 1 to 4, characterized in that the organic or inorganic acid is selected from the group consisting of nitric acid, hydrochloric acid, sulfuric acid, sulfonic acids, in particular methanesulfonic acid, carboxylic acids, sulfuric acid esters, amino acids, phosphonic acids, phosphoric acid esters and mixtures thereof or mixtures thereof with other acids having a pKa value in the range of >= 2.5 to 7.
0.
6. Fiber or fiber fragment according to one of claims 1 to 5, characterized in that the at least one silane compound is selected from the group consisting of mixed or unmixed tetraalkoxysilanes according to the general formula Si(OC x H2x+i)4 with x = 1-12, preferably selected from the group consisting of tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane and mixtures thereof.
7. Fiber or fiber fragment according to one of claims 1 to 6, characterized in that the fibers have a diameter of 50 nm to 120 pm, preferably of 30 pm to 70 pm.
8. Fiber or fiber fragment according to one of claims 1 to 7, characterized in that the fiber can be produced by a process having the following steps: a) providing an alcoholic solution of at least one silane compound selected from the group consisting of tetraalkoxysilanes, trialkoxysilanes, halosilanes and mixtures thereof, wherein the alcohol is preferably selected from the group consisting of monohydric, dihydric or trihydric, branched or unbranched alcohols, which can be aliphatic or aromatic and which is particularly preferably selected from the group consisting of ethanol, propanol, butanol, ethylene glycol, phenol and mixtures thereof;b) Providing an aqueous solution of at least one organic or inorganic acid having a pKa value of <2.5, wherein the organic acid is preferably 0.01 N to 1 N and / or wherein the content of organic acid in the aqueous solution is preferably in the range of 0.01 to 2 wt.%, preferably 0.05 to 1 wt.% and particularly preferably 0.1 to 0.5 wt.%, based on the total weight of the solution; c) Mixing the solutions provided in steps a) and b) and mixing thoroughly for 4 hours to 1 week at a temperature of 4 to 78°C, preferably 10 to 50°C; d) removing at least a portion of the alcohol from the mixture from step c) and subsequently cooling the concentrated mixture to a temperature of 20 to -25°C; e) storing the cooled mixture from step d) until a viscosity of 10 to 75 Pa-s is reached; f) spinning the mixture from step e) into continuous fibers, wherein crosslinking of the silane compound takes place during steps c) to f) and at least a portion of the organic or inorganic acid is incorporated into the resulting network and / or contributes to the crosslinking.
9. Fiber or fiber fragment according to one of claims 1 to 8, characterized in that the spinning is carried out by electrospinning, preferably with the addition of a spinning aid and at a voltage of 1 to 30 kV and at a distance of 0.2 to 30 cm, particularly preferably at a voltage of 6 to 30 kV and at a distance of 10 to 30 cm or a voltage of 1 to 5 kV and at a distance of 0.2 to 2 cm, or pressure spinning, preferably at a pressure of 10 to 60 bar, particularly preferably 20 to 40 bar.
10. Fiber or fiber fragment according to one of claims 1 to 9, characterized in that at least one further substance is contained in the sol, preferably in pure or encapsulated form.
11. Nonwovens containing silica-releasing fibers and / or fiber fragments according to one of claims 1 to 10 or consisting of these fibers.
12. Fiber nonwovens according to claim 11, characterized in that the release of the silica can be initiated and / or accelerated by bringing the fiber nonwovens into contact with an aqueous solution, which can preferably contain at least one further substance selected from the group consisting of cosmetic base materials, active ingredients, additives, auxiliaries or combinations thereof.
13. Fiber nonwovens according to claim 11 or 12 for cosmetic and / or medical use, in particular on human or animal tissue and organ barriers, such as skin, mucous membranes, intestines, and / or hair bed or nail bed, in particular for strengthening the connective tissue of, for example, skin or treating tissue weaknesses, such as in particular connective tissue weakness, preferably of the skin and vascular walls, or skin diseases, preferably inflammatory and / or chronic skin diseases, acne, age spots, neurodermatitis, decubitus, eczema, keratoses, psoriasis, dry skin, cellulitis, cellulite.
14. Nonwovens according to claim 13, characterized in that the nonwovens are contacted with an aqueous solution and massaged into the skin.
15. Fiber nonwovens according to claim 14, characterized in that the aqueous solution has a pH of preferably 3.7 to 9.0, particularly preferably 4.7 to 7.
5.
16. Nonwoven fabrics according to one of claims 14 or 15, characterized in that the aqueous solution contains further additives selected from the group consisting of • surface-active substances, especially ionic and non-ionic surfactants, saponins, fatty acids, phospholipids, ceramides, • Penetration enhancers, especially phospholipids, polyethylene glycols, glycols, ceramides, dimethyl sulfoxide, pyrrolidone, alcohols, urea or terpenes, • contains cosmetically active additives, in particular vitamins, provitamins, amino acids, heparin, hyaluronic acids, collagen (derivatives), plant extracts, probiotics, enzymes, hydrating substances, fragrances, dyes, preservatives, plasticizers, abrasive substances / particles, micelles or liposomes.
17. Cosmetic composition containing fibers or fiber fragments according to one of claims 1 to 10 or fiber nonwovens according to one of claims 11 to 16.
18. Cosmetic product according to claim 17 in the form of creams, emulsions, lotions, gels and oils for skin care, face masks, make-up bases (liquids, pastes, powders), face powders, body powders, foot powders, toilet soaps, deodorant soaps, perfumes, toilet waters and colognes, bath and shower additives (salt, foam, oil, gel), hair removal products, deodorants and antiperspirant products, hair colorants, hair waving, straightening and styling products, hair setting products, hair cleaning products (lotions, powders, shampoos), hair care products (lotions, creams, oils), styling aids (lotions, varnish, brilliantine), shaving products (including pre- and after-treatment products), make-up and make-up removing products, lip care products and cosmetics, dental and oral care products, nail care products and cosmetics, products for external intimate care, Sunscreen, self-tanner, skin bleaching, anti-wrinkle products.