Studies on Fabrication of Bilayer Scaffolds Incorporating Antibacterial and Antioxidant Agents for Wound Healing Applications

Abstract

Chitosan (CS) incorporated silver (Ag) scaffolds were synthesized with varying newlineconcentrations of Ag (1, 2, and 3 % w/w) by using a novel melt-down neutralization newlinetechnique followed by solvent curing and freeze drying. The slow and steady melting of newlinethe frozen chitosan solution allows uniform neutralization of the scaffold, resulting in newlineeven distribution of Ag throughout the CS matrix. The synthesized scaffolds (CS-Ag) newlinewere characterized by X-ray diffraction, Fourier transform infrared spectroscopy, newlinethermogravimetric analysis, and scanning electron microscopy. The in vitro degradation newlineof the scaffold was studied using the enzyme, lysozyme for 28 days. The in vitro release newlinekinetics of Ag shows an initial high release followed by slow and sustained release. The newlineCS Ag scaffolds exhibit excellent antibacterial properties against representative Grampositive newline(Staphylococcus aureus) and Gram-negative (Escherichia coli) bacterial cultures. newlineThe antibacterial activity of scaffolds increases with the concentration of Ag. The in vitro newlinebiocompatibility of the CS Ag scaffolds was studied using HaCaT cells (keratinocytes) newlineby the MTT assay. The scaffolds are biocompatible and support cell adhesion and newlineproliferation without exhibiting any toxicity. The CS Ag scaffolds are proposed as newlinepromising candidates for treating bacterial infections in tissue engineering applications. newlineScaffolds with different concentrations (0.5, 1 and 2% w/w) of antioxidants (SM/ CM/ newlineEA) incorporated within the collagen (CO) and CS matrix were synthesized with an aim newlineto incorporate antioxidant properties within the supporting matrix. The structural newlinecharacterization of the scaffolds was carried out by XRD and FTIR, which confirmed the newlinepresence of antioxidants (SM/ CM/ EA) within the CS-CO matrix. The synthesized newlinescaffolds exhibited sustained release of antioxidants in phosphate buffered saline for 120 newlineh. The scaffolds were biocompatible and supported the growth of COS7 (fibroblast) cells. newlineThe CS-CO scaffolds incorporated with antioxidants and seeded with cell