Bandage modified with antibacterial films of quaternized chitosan & sodium carboxymethyl cellulose microgels/baicalein nanoparticles for accelerating infected wound healing.

Wound dressings capable of sterilizing pathogenic bacteria and scavenging free radicals are important to inhibit bacterial invasion and accelerate wound healing. The target of this work is to develop an antibacterial dressing by modifying bandages with films composed of biological macromolecule microgels and baicalein@tannic acid (Bai@TA) nanoparticles (NPs). Firstly, hydrophobic Bai was made into water soluble Bai@TA NPs using a solvent exchange method with TA as stabilizer. Polymeric microgels of sodium carboxymethyl cellulose (CMC)&hydroxypropyltrimethyl ammonium chloride chitosan (HACC) were then prepared by a simple blending method. Further, CMC&HACC/Bai@TA multilayer films were deposited on medical bandages by using a layer-by-layer assembly technique to obtain an antibacterial dressing. The as-prepared dressings showed great antibacterial ability against E. coli, S. aureus and methicillin resistant Staphylococcus aureus (MRSA), excellent antioxidant activity and good biological safety. In addition, compared to conventional medical bandages, the dressings could efficaciously diminish inflammation in the wound, accelerate skin regeneration and functional restoration, and promote the in vivo healing speed of full-thickness skin wounds infected by MRSA. We believe that as a low-cost but effective wound dressing, the antibacterial bandage modified with CMC&HACC/Bai@TA films has potentials to replace traditional dressings in the clinical management of infected wounds.