Preparation and Evaluation of Nanocomposite Hydrogels Based on Alginate and Chitosan Nanofibers for Wound Healing

Abstract

Most of the traditional wound dressings used to heal full-thickness skin wounds cannot support all the clinical requirements due to their lack of multifunctionality. Bilayer wound dressings, which composed of two layers based on nanofiber and hydrogel with multifunctional properties, can be attractive for effective skin regeneration. Material and method Herein, we designed a multifunctional bilayer scaffold containing of Chitosan-Polycaprolactone nanofiber (PC) and tannic acid (TA) reinforced double network methacrylated gelatin (GM) and alginate (Al) hydrogel (GM/Al/TA). The electrospun PC nanofibers (outer layer) were coated with GM/Al/TA hydrogel (lower layer) to obtain a Bi-TA nanocomposite scaffold for mimicking the skin epidermis and dermis, respectively. Results The GM/Al/TA hydrogel layer of Bi-TA showed antibacterial effect (p < 0.0001), free radical scavenging capacity (p < 0.0001), and biocompatibility properties. The presence of PC nanofiber acted as a barrier for preventing bacterial invasion and moisture loss of the hydrogel layer. The wound healing performance of the Bi-TA scaffold was compared with PC, GM/Al/TA hydrogel, 3M commercial dressing, and the sterile gauze placed on the wound site via a rat full-thickness wound model. Moreover, the tissue samples were assessed by histopathological and immunohistochemical (IHC) stainings of transforming growth factor-β1(TGF-β1) and tumor necrosis factor-α (TNF-α). The results presented an enhanced wound closure rate, effective collagen deposition, quick re-epithelialization, more skin appendages, and replacement of defect area with normal skin tissue by Bi-TA scaffold compared to other groups. Additionally, the regulation of TGF-β1 and TNF-α was observed by Bi-TA dressing. Conclusion Taken together, the Bi-TA with structural and multifunctional appropriate possessions can be an excellent candidate for developing effective dressings for wound healing applications.