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US-12617824-B2 - Silk protein coatings

US12617824B2US 12617824 B2US12617824 B2US 12617824B2US-12617824-B2

Abstract

The present invention relates to a method for coating an inert or naturally occurring material with a silk polypeptide. It further relates to a coated inert or naturally occurring material obtainable by said method and to uses thereof. It also relates to products comprising said coated material.

Inventors

  • Axel H. Leimer
  • Lin Romer

Assignees

  • AMSILK GMBH

Dates

Publication Date
20260505
Application Date
20190124
Priority Date
20091208

Claims (19)

  1. 1 . A method of coating hair or skin with a silk polypeptide, the method comprising the steps of: i) providing an aqueous solution of the silk polypeptide, and ii) applying the solution on the hair or skin, thereby coating the hair or skin with the silk polypeptide and improving hydrophilicity of the hair or skin, wherein the silk polypeptide consists of (C) m , (C) m NR z , NR z (C) m , or NR z (C) m NR z ; or the silk polypeptide consists of (C) m , (C) m NR z , NR z (C) m , or NR z (C) m NR z linked to an artificial tag, wherein the tag is a lipid, a dye, a conjugated metal, an activated carbon, or a tag to facilitate purification of the silk polypeptide, wherein C is a repetitive unit having an amino acid sequence of SEQ ID NO: 21, m is an integer from 2 to 80, NR is a non-repetitive (NR) unit NR3 having the amino acid sequence of SEQ ID NO: 41 or NR4 having the amino acid sequence of SEQ ID NO: 42, and z is an integer from 1 to 3.
  2. 2 . The method of claim 1 , wherein the hair is human hair or animal hair.
  3. 3 . The method of claim 1 , where the hair is hair for extensions, periwigs, hair pieces, or toupees.
  4. 4 . The method of claim 1 , wherein the solution is applied using dip coating, spray coating or padding.
  5. 5 . The method of claim 1 , wherein the concentration of the silk polypeptide in the solution is in the range of 0.1 wt %/vol to 30 wt %/vol.
  6. 6 . A naturally occurring material coated with a silk polypeptide and obtainable by the method of claim 1 , wherein the natural occurring material is hair or skin and wherein the silk polypeptide consists of (C) m , (C) m NR z , NR z (C) m , or NR z (C) m NR z ; or the silk polypeptide consists of (C) m , (C) m NR z , NR z (C) m , or NR z (C) m NR z linked to an artificial tag, wherein the tag is a lipid, a dye, a conjugated metal, an activated carbon, or a tag to facilitate purification of the silk polypeptide, wherein C is a repetitive unit having the amino acid sequence of SEQ ID NO: 21, m is an integer from 2 to 80, NR is a non-repetitive (NR) unit NR3 having the amino acid sequence of SEQ ID NO: 41 or NR4 having the amino acid sequence of SEQ ID NO: 42, and z is an integer from 1 to 3.
  7. 7 . The method of claim 1 , wherein the artificial tag to facilitate the purification of said silk polypeptide is a T7 tag.
  8. 8 . The material of claim 6 , wherein the artificial tag to facilitate the purification of said silk polypeptide is a T7 tag.
  9. 9 . The method of claim 1 , wherein the silk polypeptide is C 16 .
  10. 10 . The method of claim 6 , wherein the silk polypeptide is C 16 .
  11. 11 . The method of claim 1 , wherein the aqueous solution of the silk polypeptide is prepared by first dissolving the silk polypeptide in guanidine thiocyanate or urea solution and then dialyzed against water or a Tris buffer.
  12. 12 . The method of claim 6 , wherein the aqueous solution of the silk polypeptide is prepared by first dissolving the silk polypeptide in guanidine thiocyanate or urea solution and then dialyzed against water or a Tris buffer.
  13. 13 . The method of claim 1 , wherein the silk polypeptide coating on the hair or skin has a thickness range from 1 nm to 50 μm.
  14. 14 . The method of claim 6 , wherein the silk polypeptide coating on the hair or skin has a thickness range from 1 nm to 50 μm.
  15. 15 . The method of claim 13 , wherein the silk polypeptide coating on the hair or skin has a thickness range from 0.5 μm to 10 μm.
  16. 16 . The method of claim 14 , wherein the silk polypeptide coating on the hair or skin has a thickness range from 0.5 μm to 10 μm.
  17. 17 . The method of claim 15 , wherein the silk polypeptide coating on the hair or skin has a thickness range from 1.0 μm to 5 μm.
  18. 18 . The method of claim 16 , wherein the silk polypeptide coating on the hair or skin has a thickness range from 1.0 μm to 5 μm.
  19. 19 . A method of coating hair or skin with a silk polypeptide, the method comprising the steps of: i) providing an aqueous solution of the silk polypeptide, and ii) applying the solution on the hair or skin, thereby coating the hair or skin with the silk polypeptide and improving hydrophilicity of the hair or skin, wherein the silk polypeptide consists of (C) m , (C) m NR z , NR z (C) m , or NR z (C) m NR z , wherein C is a repetitive unit having an amino acid sequence of SEQ ID NO: 21, m is an integer from 2 to 80, NR is a non-repetitive (NR) unit NR3 having the amino acid sequence of SEQ ID NO: 41 or NR4 having the amino acid sequence of SEQ ID NO: 42, and z is an integer from 1 to 3, wherein the silk polypeptide directly adheres to the hair or skin.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a divisional of U.S. application Ser. No. 14/958,775, filed Dec. 3, 2015, which is a divisional of U.S. application Ser. No. 13/514,265, filed Jun. 6, 2012, now U.S. Pat. No. 9,217,017, which is a U.S. National Phase Application of PCT/EP2010/007440, international filing date Dec. 7, 2010, which claims priority to EP 09015193.7 filed Dec. 8, 2009 and claims the benefit of U.S. Provisional Application No. 61/267,596, filed Dec. 8, 2009, the disclosures of which are incorporated herein by reference. The present invention relates to a method for coating an inert or naturally occurring material with a silk polypeptide. It further relates to a coated inert or naturally occurring material obtainable by said method and to uses thereof. The present invention also relates to products comprising said coated material. BACKGROUND OF THE INVENTION Spider silks are protein polymers that display extraordinary physical properties. Among the different types of spider silks, draglines are most intensely studied. Dragline silks are utilized by orb weaving spiders to build frame and radii of their webs and as lifelines. For both purposes high tensile strength and elasticity are required. The combination of such properties results in a toughness that is higher than that of most other known materials. The dragline silk of Araneus diadematus, for example, demonstrates high tensile strength of 1.9 Gpa approximately equivalent to that of steel (1.3 Gpa) and aramid fibers. Systems for the recombinant production of spider silk proteins in E. coli have been developed earlier (WO 2006/008163, WO 2006/002827). As an example, it is referred to WO 2006/008163 (claiming priority of U.S. provisional application No. 60/590,196). In this expression system, single building blocks (=modules) can be varied freely and can thus be adapted to the requirements of the specific case. Modules of this type are disclosed also in Hummerich, D., Helsen, C. W., Oschmann, J., Rudolph, R. & Scheibel, T. (2004): “Primary structure elements of dragline silks and their contribution to protein solubility and assembly, Biochemistry 43, 13604-13612”. Further modules are described in WO 2007/025719. It is known from nature that spider silk proteins can be processed into threads. Spiders are experts in using different types of proteins to form silk threads and cobwebs. Technical processes to transform spider silk proteins into threads have been described, for example, in WO 2007/031301. Synthetic or inorganic materials, e.g. synthetic or inorganic fibers, have been important for the industry for decades. Among these, the aramid thread kevlar, for example, is five times stronger than steel on an equal weight basis, yet, at the same time is lightweight. It also shows low electrical conductivity and has a very high chemical resistance—it is inert. On the one hand, this condition is desired, e.g. for protective clothing. On the other hand, however, aramid threads are very difficult to modify after production. It is nearly impossible to efficiently dye aramid threads or to attach molecules to the surface of aramid threads. Aramid threads are also only slightly wettable. This is also true for other inert synthetic or inorganic materials—they have a high chemical resistance, are only slightly wettable and can not be modified after polymerization under mild conditions, i.e. under low temperatures and without the use of toxic solvents. Common coatings either do not stick well to the surface of inert synthetic or inorganic materials, e.g. inert synthetic or inorganic fibers, and common coatings are not very durable or have to be applied under harsh conditions, i.e. high temperatures and/or toxic solvents. Thus, there is a need for novel, suitable methods to modify inert synthetic or inorganic materials, e.g. inert synthetic or inorganic threads, after production, preferably at low temperatures and without the use of toxic solvents. The inventors of the present invention have surprisingly found that the use of silk polypeptides as coating materials provides a highly efficient coating under mildest conditions and enables the manufacture of silk coated inert synthetic or inorganic materials tailored for specific applications. Up to now, very harsh conditions (if at all), like plasma treatment, were necessary to alter inert synthetic or inorganic materials, e.g. inert synthetic or inorganic fibers. There is also no method of coating inert synthetic or inorganic material available employing silk polypeptides, and, more importantly, no one thought about coating existing inert synthetic or inorganic fibers with a layer of pure silk—as this seemed completely impossible so far. The inventive coating allows attachment of molecules under mild conditions, i.e. under low temperatures and without the use of toxic solvents, to inert synthetic or inorganic materials. In the medical technology, for example, agents, such as pharmaceuti