EP-4735065-A1 - WOUND DRESSINGS

Abstract

The invention relates to wound dressings in the form of tissue scaffolds, gels and powders. The wound dressing comprising at least one polymer material and a coating agent coating the at least one polymer material, wherein the wound dressing is incorporated with an effective amount of an antimicrobial agent. The invention also extends to methods of making the wound dressings and also extends to wound dressings produced in accordance with the methods of the invention.

Inventors

• MOLOTO, Nosipho
• SHUMBULA, Ndivhuwo
• NDALA, Zakhele
• MENTE, Pumza
• MOFOKENG, Thapelo
• NKABINDE, Siyabonga Sipho
• MLAMBO, Mbuso
• TETYANA, Phumlani
• JENGELE-TETYANA, Zikhona

Assignees

• University Of The Witwatersrand, Johannesburg
• Mintek

Dates

Publication Date

20260506

Application Date

20240628

Claims (20)

1. 1 . A tissue scaffold comprising at least one polymer material and a coating agent coating the at least one polymer material, wherein the tissue scaffold is optionally incorporated with an effective amount of an antimicrobial agent.
2. 2. The tissue scaffold according to claim 1 , wherein the at least one polymer material comprises a first polymer material and a second polymer material.
3. 3. The tissue scaffold according to claim 2, wherein the first polymer material is bonded with the second polymer material.
4. 4. The tissue scaffold according to claim 2 or 3, wherein the at least one polymer material comprising the first and second polymer materials is selected from synthetic polymers, natural polymers such as organic polymers, and combinations thereof.
5. 5. The tissue scaffold according to claim 4, wherein the first polymer material is a polysaccharide such as chitosan.
6. 6. The tissue scaffold according to claim 4 or 5, wherein the second polymer material is a protein-based polymer material such as gelatin.
7. 7. The tissue scaffold according to any one of claims 2 to 6, wherein the first and second polymer materials are bonded by cross-linking.
8. 8. The tissue scaffold according to claim 1 , wherein the at least one polymer material comprises or consists of a first polymer material.
9. 9. The tissue scaffold according to claim 8, wherein the first polymer material is selected from synthetic polymers, and natural polymers such as organic polymers.
10. 10. The tissue scaffold according to any one of the preceding claims, wherein the coating agent is not optional, and wherein the coating agent is a biopolymer material, such as polydopamine (PDA).
11. 11. The tissue scaffold according to any one of the preceding claims, wherein the antimicrobial agent is silver or copper nanoparticles, preferably silver nanoparticles.
12. 12. The tissue scaffold according to any one of the preceding claims, incorporating pores arranged to absorb wound exudate, wherein the pores are on a surface of the tissue scaffold and at least partly traverse into the tissue scaffold.
13. 13. The tissue scaffold according to any one of claims 8 to 12, wherein the tissue scaffold is a 2D scaffold comprising the at least one polymer material comprising or consisting of the first polymer material.
14. 14. The tissue scaffold according to any one of claims 2 to 7 and 10 to 12, wherein the tissue scaffold is a 2D scaffold comprising the at least one polymer material comprising the first polymer material and second polymer material.
15. 15. The tissue scaffold according to any one of claims 2 to 7 and 10 to 12, wherein the tissue scaffold is a 3D scaffold comprising the first polymer material and second polymer material.
16. 16. A method of making a tissue scaffold, the method including: contacting at least one polymer with a coating agent and an effective amount of an antimicrobial agent, thus obtaining a mixture containing the at least one polymer, coating agent and antimicrobial agent; and drying the mixture containing the at least one polymer, coating agent and antimicrobial agent, thus obtaining the tissue scaffold.
17. 17. The method according to claim 16, wherein the at least one polymer is comprised in a solution comprising a first polymer and a second polymer.
18. 18. The method according to claim 17, wherein prior to forming the solution comprising the first and second polymers, the method includes: contacting a first solution comprising the first polymer with a second solution comprising the second polymer, and contacting a bonding agent with one of the first and second solutions, preferably the first solution, prior to contacting the first solution with the second solution.
19. 19. The method according to claim 18, wherein the bonding agent is a crosslinking agent that is arranged to facilitate the crosslinking of the first polymer with the second polymer.
20. 20. The method according to claim 18 or claim 19, wherein the bonding agent is a natural crosslinking agent such as genipin.

Description

WOUND DRESSINGS FIELD OF INVENTION THIS INVENTION is in the field of wound dressings, in particular scaffolds, more in particular permanent tissue scaffolds for use in skin and tissue regeneration. The invention extends to a method of making the wound dressing, in particular the scaffold. The invention further extends to the use of the wound dressing in healing a wound. The invention further extends to the wound dressing for use in a method of treating a wound. BACKGROUND TO THE INVENTION Recent developments in advanced technology and nanotechnology have proven to be promising solutions in therapeutics, including wound care management. Advanced wound dressings in the form of hydrocolloids, films, foams, hydrogels and scaffolds have been designed and used to solve health problems underlying wound care treatments. These wound dressings are designed to meet ideal requirements which include the ability to maintain a balanced moist environment, adherence to the wound, allow the exchange of oxygen and prevent bacterial infection. The requirements ensure the acceleration of wound healing and reduce the complications that are associated with the process. Wound dressings are designed as either temporary or permanent dressings. Temporary wound dressings provide, and control wound exudate absorption and protect them until closure. They also prevent or protect wounds from bacterial infection provided they contain an antimicrobial agent. These dressings are most suitable for superficial wounds, and they require to be changed to avoid bacterial contamination. Permanent dressings on the other hand tend to integrate with the skin and accelerate the tissue regeneration process. These dressings are designed in the form of tissue scaffolds that influence cell migration, adhesion, and proliferation to promote epidermal regeneration and reduce scarring. Tissue scaffolds are suitable for deep chronic wounds that are too complicated to heal through conventional treatments. They are usually designed from natural and/or synthetic polymers. Only biocompatible and biodegradable polymers are used for the fabrication of tissue scaffolds. This is because the scaffolds are embedded in the wound and integrate with the skin tissue, therefore their toxicity must be thoroughly controlled. Synthetic polymers that have proven to be the best candidates for skin tissue scaffolds include poly(glycolic acid) (PGA), polyethylene glycol (PEG), poly(caprolactone) (PCL), poly(lactic-co-glycolic) acid (PLGA), polyvinylpyrrolidone (PVP) and polyurethane (Pll). These polymers are biocompatible, nontoxic, structurally stable, and biodegradable which makes them suitable to be applied in skin tissue regeneration. Natural polymers are derived from natural sources like plants and animals. By nature, they are biocompatible and biodegradable which makes them even more suitable for designing skin tissue scaffolds. The most used natural polymers in skin tissue scaffolds include alginate, dextran, chitosan, collagen, and gelatine. One of the main requirements for skin tissue scaffolds is the ability to prevent bacterial infection. However, some natural and synthetic polymers are not antimicrobial active which is one of the drawbacks when it comes to wound healing. Bacterial infection is still a formidable issue in the wound healing process. Various approaches to dealing with bacterial infection in the wound-healing process have been reported. These include incorporating antibiotics and plant extracts, or antimicrobial active metal nanoparticles (NPs) on the scaffolds. It is the object of the present invention to develop active tissue scaffolds that can be applied in the treatment of deep chronic wounds. It is particularly an object of the present invention to prepare a permanent nanocomposite scaffold for use in wound healing. SUMMARY OF THE INVENTION IN ACCORDANCE WITH A FIRST ASPECT OF THE INVENTION, THERE IS PROVIDED a wound dressing, in particular a tissue scaffold, the wound dressing comprising at least one polymer material and a coating agent coating the at least one polymer material, wherein the wound dressing is incorporated with an effective amount of an antimicrobial agent. The at least one polymer material may be selected from synthetic polymers, natural polymers such as organic polymers, and combinations thereof. The at least one polymer material may comprise a first polymer material and/or a second polymer material. The first polymer material may be bonded, in particular crosslinked, with the second polymer material. The first polymer material may be a polysaccharide, such as, chitosan. The second polymer material may be a protein-based polymer material, such as, gelatin. The first and second polymer materials may be bonded by cross-linking. The coating agent may be a biopolymer material, such as, polydopamine (PDA). The antimicrobial agent may be silver or copper nanoparticles. The wound dressing may incorporate pores designed to absorb wound e