Enhanced Biocompatibility and Antibacterial Efficacy of Chitosan/Neem/ZnFe2O4 Composite Coatings on Biodegradable Magnesium AZ31B Wire for Intestinal Anastomosis: In Vitro and in Vivo Studies

Abstract

The fast degradation rate, hydrogen evolution, and low corrosion rate are some of the major challenges faced when using Magnesium AZ31B wire of 0.3 mm diameter. This study aims to develop and characterize a novel coating for AZ31B wires to augment their antibacterial activity, wound healing properties, and corrosion resistance. Herein, a novel composite coating, composed of ZnFe2O4 nanoparticles and Neem extract integrated with Chitosan as matrix was deposited on Mg wire via electrodeposition. Composite coated wire was later dip coated by PLA to prevent the coating surface from any damage. Scanning electron microscopy (SEM) shows that the electrodeposited coating has a compact and uniform structure. Mechanical testing revealed an enhancement in the breaking force of the coated sutures, increasing from 250N for uncoated Mg AZ31B to 330N for the coated ones. Electrochemical test, and hydrogen evolution measurement indicate that the coating effectively reduces the degradation rate of Mg substrates. The degradation studies were performed in Simulated Gastric Fluid (SGF) to determine the durability of the wire. Drug release tests showed a burst release in the first 24 hours, followed by sustained release over time up to 96 hours. The antimicrobial activity of the coated wire was evaluated against E. coli(26mm), S. aureus(30mm), K. pneumoniae(24mm) and E. faecalis(30mm) 20% composite exhibited superior zones of inhibition. Hemolysis testing indicated that 20% composite exhibited the hemolysis percentage at 0.3%, within the acceptable range for biomedical applications. Analysis of DPPH(1,1-diphenyl -2-picrylhydrazyl) assay results revealed escalated antioxidant activity with increasing concentration of ZnFe2O4 as 84% for 20% Chi/Neem/ ZnFe2O4 composite. Furthermore, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was done to determine cell viability percentage for the cell lines of intestinal epithelial cells (IEC-6). The result indicates that this coating shows a great potential application for intestinal anastomosis.