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US-12617909-B1 - Free standing metal-ion doped thin films

US12617909B1US 12617909 B1US12617909 B1US 12617909B1US-12617909-B1

Abstract

The present disclosure provides a thin film self-assembled from polymer(s), where the thin film includes a metal ion so it can further undergo ion exchange to incorporate an ion or blend of ions. Methods for making these thin films, subsequently top coating them so they can be freed from their original substrate, and methods of using these thin films are also disclosed.

Inventors

  • Kevin Krogman

Assignees

  • Silverpeutics, Inc.

Dates

Publication Date
20260505
Application Date
20250616

Claims (17)

  1. 1 . A method for depositing a film on a hydrophobic silicone substrate, the method comprising: (a) depositing a first deposition solution comprising at least one positively charged polymer, wherein the pH of the solution is at or above the pK a of the at least one positively charged polymer and wherein the first deposition occurs for about 8 seconds to about 30 seconds to form a first layer of said first deposition material; (b) applying a rinse solution to remove any excess unbound polymer from the first deposition solution, allowing it to reside on the surface for a period of time t rinse of about 8-90 seconds; (c) removing excess rinse solution using a diffusion barrier removal step whereby a layer of rinse solution of 2-5 microns is left on the positively charged polymer layer; (d) depositing a second deposition solution comprising at least one negatively charged polymer, wherein the pH of the solution is at or above the pK a of the at least one negatively charged polymer, the second deposition solution contains a counterion for the at least one negatively charged polymer, wherein the counterion is provided by one or more of calcium nitrate, aluminum nitrate, copper chloride, magnesium chloride, manganese chloride, sodium chloride, calcium chloride, potassium chloride, copper sulfate, magnesium sulfate, sodium acetate, calcium acetate, sodium carbonate, potassium carbonate, calcium carbonate, or manganese carbonate, and wherein the second deposition occurs for about 8 seconds to about 30 seconds to form a second layer of said second deposition material; (e) applying a rinse solution to remove any excess unbound negatively charged polymer from the second deposition solution, allowing it to reside on the surface for a period of time t rinse of about 8-90 seconds; (f) removing excess rinse solution using a diffusion barrier removal step whereby a layer of rinse solution of 2-5 microns is left on a second layer made from the second deposition material; (g) exposing the the second layer to a metal ion solution for a period of about 45 seconds to 3 minutes, whereby the counterion is exchanged for a metal ion from the metal ion solution; (h) applying a first rinse solution to remove any unbound excess metal ions for a period of time t rinse equal to about 45 seconds to about 3 minutes; (i) applying a reducing solution to the the second layer of the second deposition solution for a period of about 45 sec to 3 minutes; (j) applying a second rinse solution for a period of time t rinse equal to about 45 seconds to about 3 minutes; and (k) drying to form a completed film.
  2. 2 . The method of claim 1 , wherein the metal ion replacing the counterion is selected from gallium ion, cerium ion, or silver ion.
  3. 3 . The method of claim 1 , wherein steps g-j are repeated for up to about five (5) cycles, prior to step (e).
  4. 4 . The method of claim 2 , wherein the metal ion solution comprises silver nitrate having a concentration between about 1 mM to about 10 mM.
  5. 5 . The method of claim 1 , wherein the reducing solution comprises sodium borohydride having a reductive potential between about −300 mV and about −500 mV.
  6. 6 . The method of claim 1 , wherein the completed film comprises dimensions that are at least one foot wide and at least three feet in length.
  7. 7 . The method of claim 3 , further comprising depositing a third deposition solution comprising a hydrophilic polymer and substantially drying it to form a layer of the hydrophilic polymer less than 5 mil (125 micron) thick.
  8. 8 . The method of claim 7 , wherein the hydrophilic polymer is a generally regarded as safe hydrophilic polymer.
  9. 9 . The method of claim 7 , wherein the hydrophilic polymer is a polyvinyl alcohol.
  10. 10 . The method of claim 7 , further comprising blending an additive into the solution of hydrophilic polymer so that the additive incorporates into the completed film.
  11. 11 . The method of claim 10 , wherein the additive is an antibiotic, a salicylic acid, a hydroquinone, a retinoid, a hyaluronic acid, or a vitamin C.
  12. 12 . The method of claim 1 , wherein steps a-f are repeated for up to 50 cycles, prior to step g.
  13. 13 . The method of claim 1 , wherein the at least one positively charged polymer achieves its charge from some combination of primary amine, secondary amine, tertiary amines, imine, amido, or amine or is selected from poly(allylamine hydrochloride) (PAH), poly-lysine (PLL), linear or branched poly(ethylene imine) (PEI), poly(histidine), poly(N,N-dimethyl aminoacrylate), poly(N,N,N-trimethylaminoacrylate chloride), poly(methyacrylamidopropyltrimethyl ammonium chloride), and chitosan.
  14. 14 . The method of claim 13 , wherein the one positively charged polymer is poly(allylamine hydrochloride) (PAH).
  15. 15 . The method of claim 1 , wherein the at least one negatively charged polymer is selected from poly(acrylic acid) (PAA), alginate, hyaluronic acid, heparin, heparin sulfate, chondroitin sulfate, dextran sulfate, poly(methacrylic acid), oxidized cellulose, carboxymethyl cellulose, polyaspartic acid, and polyglutamic acid.
  16. 16 . The method of claim 15 , wherein the one negatively charged polymer is poly(acrylic acid) (PAA).
  17. 17 . The method of claim 1 , wherein the second deposition solution comprises calcium nitrate.

Description

This application claims priority to U.S. provisional application Ser. No. 63/715,547 filed Nov. 2, 2024, and U.S. provisional application Ser. No. 63/722,232 filed Nov. 19, 2024. BACKGROUND Layer by layer (LbL) assembly is a process that builds surface coatings by alternately depositing two different and complementary materials. Alternation of the two materials forms bilayers, and bilayers are the building blocks of LbL coatings. The process commonly relies on electrostatic interactions and is self-limiting in each incremental deposition step. For example, charge-reversals that occur during the process eliminate the thermodynamic favorability of additional molecules being adsorbed to the growing film. Skin wound healing involves multiple processes: (1) hemostasis, (2) inflammation, (3) proliferation, and (4) remodeling. Inflammation is a tissue defense mechanism, and provides resistance to microbial contaminations. Inflammation occurs almost simultaneously with hemostasis, and starts from within a few minutes to 24 h from injury and lasts for about 3 days. Proliferation starts at approximately day 3, in which keratinocytes and fibroblasts start to proliferate and migrate toward the wound. Failed regulation of any particular process results in pathologically compromised wound healing, such as chronic wounds, which are characterized by a prolonged or excessive inflammatory phase, persistent infections, and delayed wound contraction. During the inflammatory phase, vascular contraction increases vascular permeability, allowing neutrophils, macrophages, and lymphocytes to invade. Cell proliferation is the next stage, and it is generally acknowledged that fibroblasts are necessary for both cell proliferation and the development of new blood vessels since they release collagen. During the remodeling phase, collagen near the injury site is reorganized, and angiogenesis activity is stopped. Additionally, collagenase then mediates the recycling of collagen, with too much collagen at the injury site eventually leading to the creation of hard scars. SUMMARY The disclosure here relates to thin films made from polymers such as poly(diallyl dimethyl ammonium chloride) (PDAC), polyacrylic acid (PAA), poly(styrene sulfonate) (PSS), poly(vinyl sulfonic acid), Chitosan, CMC, polyallylamine hydrochloride (PAH), hyaluronic acid, polysaccharides, DNA, RNA, proteins, LPEI, BPEI, polysilicic acid, poly(3,4-ethylenedioxythiophene) (PEDOT) and combinations thereof with other polymers (e.g. PEDOT:PSS), copolymers of the abovementioned, and the like. The weight-average molecular weight of the polymer may be about 50,000 Daltons or more, 40,000 Daltons or more, 30,000 Daltons or more, 20,000 Daltons or more, 15,000 Daltons or more, 10,000 Daltons or more, or 5,000 Daltons or more. In an aspect, the thin film is made from PAH (polyallylamine hydrochloride) and PAA (polyacrylic acid). One of or both of the PAH and PAA can be functionalized with trimethoxysilane. Thin films of the disclosure can be made by using wet coating techniques to make a layer or layers of polymer(s), after which the wet film can be dried. Applicable wet coating techniques include, for example, reverse-roll coating, knife-over-roll coating, Meyer rod coating, gravure, slot-die, dip coating, spin coating, and spray coating. Other methods for making the thin films herein include, for example, immersion, inkjet, flexographic, metering rod, blade, air knife, curtain, melt extrusion, solvent casting and any combinations of the methods described above. These techniques can be applied using roll-to-roll techniques, whereby flexible substrate is passed over a series of rollers starting and ending with a wrapped roll of substrate, dipped techniques, whereby the substrate is submerged serially into baths of solution, or spray techniques, whereby the substrate is exposed serially to sprayed fluid comprising the desired solutions. The thin films can include a metal and/or metal ion. The metal and/or metal ion can be any metal or metal ion including, for example, silver, gallium, or cerium. The silver, gallium, or cerium can be present in the thin film as an ion and/or in an uncharged state. The active agent can also be for example, metallic particles, and metal ion antimicrobial agents. The metal ion antimicrobial agent can be a metal ion, metal ion salt, or metal ion nanoparticle. The metal ion nanoparticle can be a silver nanoparticle to act as a reservoir of the active metal itself. The antimicrobial agent can be, for example, silver, chlorhexidine, antibiotics, polyhexamethylene biguanide (PHMB), iodine, cadexomer iodine, povidone iodine (PVI), hydrogen peroxide, and vinegar (acetic acid). Similarly, gallium can be incorporated as an active agent to provide antibiofilm functionality, or cerium can be incorporated as an active agent to benefit burn management by producing a hardened burn eschar. In an aspect, thin films described herein can be used as a vehicle delivering d