Antibacterial and antioxidant wound dressings with pH responsive release properties accelerate chronic wound healing

Accelerating chronic wound healing is of great clinical significance. In this study, a bilayer pad (PCL-TH/PVAAlg@CUR) with tetracycline hydrochloride (TH) loaded polycaprolactone (PCL) nanofiber as the outer layer (PCL-TH), and poly (vinyl alcohol) (PVA) hydrogel loaded with sodium alginate microspheres (Alg) encapsulating of curcumin (CUR) as the inner layer (PVA-Alg@CUR) was prepared to accelerate the chronic wound healing. The prepared bilayer pad shows a porous structure and can release CUR specifically according to the pH of chronic wounds. Moreover, it has good water vapor transmittance and water absorption ability, and its mechanical properties can meet the daily expansion and contraction of the skin. The antimicrobial and antioxidant properties of the bilayer pads were verified by the inhibition zone, co-culture method and in vitro free radical scavenging experiments. In addition, in vivo experiments have shown that the bilayer pad can inhibit the bacteria at the wound site and accelerate the healing of the chronic diabetic wound infected by bacteria. This study indicates the prepared antibacterial and antioxidant bilayer dressing with pH responsive release property have potential clinical applications.