Nanosilver loaded GelMA hydrogel for antimicrobial coating of biomedical implants

Bacterial adhesion to the surface of implants in surgical procedures represents a major problem in surgeries, as it incurs high medical costs and could lead to postoperative infections. Different strategies have been developed to decrease the incidence of bacterial infections related medical devices failure. One approach is the modification of the surface of the devices using antibacterial coatings designed to be non-fouling, thus minimizing microbial adhesion. The ability of silver nanoparticles to destroy infectious micro-organisms makes them an attractive candidate for use against "super-bugs" resistant to antibiotics. In this work, we develop a silver nanoparticles loaded methacrylated gelatin (GelMA) hydrogel for antimicrobial coating of biomedical implants. Silver nanoparticles of different sizes and concentrations were synthesized using citrate and ascorbic acid reduction in glycerol water mixtures which were incorporated in an Ultraviolet (UV)-photocrosslinkable GelMA hydrogel. Analysis and characterization of the obtained hydrogels were performed through scanning electron microscopy (SEM), and UV-visible spectrophotometry. The release of silver nanoparticles from the crosslinked hydrogel was quantified using UV spectroscopy. The cell viability was investigated on Rat Aortic Smooth Muscle Cells (RASMC) using different concentrations and sizes of silver nanoparticle loaded GelMA hydrogel. The antibacterial activities of the newly developed hydrogel coating was tested on two different types of bacteria, gram positive Staphylococcus aureus and gram negative Escherichia coli by analyzing the growth of the bacterial cells following treatment with different concentration and size of silver nanoparticles. Experimental results revealed that incorporation of silver nanoparticles in GelMA hydrogel was successfully performed and the release of silver nanoparticles over time from the developed hydrogel to the pathogenic environment was successfully achieved which reduced bacterial growth without any negative effect on cells.