Polydopamine coating of uncrosslinked chitosan as an acellular scaffold for full thickness skin grafts

•Development of uncrosslinked chitosan membranes coated with polydopamine.•Toxic crosslinking agents are avoided while mechanical properties are preserved.•Bioactivity is enhanced while bacterial contamination is reduced.•Rapid healing of full thickness wounds is achieved in vivo (5 days).•A novel, yet simple, method and biomaterial for the treatment of large area wounds. There is an unmet need for skin grafting materials that are readily available for large area wounds, due to complex, lengthy and costly manufacturing processes that are not compatible with this type of wounds. Here we developed an acellular skin graft material based on surface coating of uncrosslinked porous (UCLP) chitosan. UCLP chitosan membranes had mechanical properties in ranges suitable for skin grafting. Polydopamine (PDA) coating improved hydrophilicity and resulted in a significant increase in attachment and metabolic activity of mammalian cells in vitro. PDA coating also decreased the attachment of pseudomonas aeruginosa - a common bacteria infecting skin wounds. Finally, the PDA-coated membranes were implanted in full thickness surgical wounds in a rodent model and resulted in complete would closure in 5 days. The current study suggests that PDA-coated UCLP chitosan membranes could be a simple and effective strategy for the development of grafting materials for large area wounds.