Bio-Active Antimicrobial Silver-Chitosan Composite Coating on 316L Stainless Steel by Electrophoretic Deposition Method

Abstract

316L Stainless steel is used extensively as medical implants which also includes pins, screws and orthopedic implants like total hip and knee replacements. So it would be beneficial to apply antimicrobial coating on 316L Stainless steel to minimize the risk of infection from open wounds and surgical conditions. In this research Silver-Chitosan composite was coated on 316L Stainless steel sample to make it an antimicrobial surface. Silver has been used as an antibacterial agent due to its strong inhibiting effect on bacteria. Silver has the properties like to obtain desired shape and size , easy handling for surface modification and ability of silver ions torelease themselves efficiently. Silver also has the added benefit of being less toxic to human tissues than harmful microorganisms. Chitosan is used along with silver to induce more antibacterial property of the biomaterial. Application of chitosan is due to its biodegradability, biocompatibility and non-toxic to human tissues. Also Chitosan exhibits an antibacterial activity to both Gram-positive and Gram-negative bacterial strains. Due to these unique properties, Chitosan and its derivatives are used as biomaterials in medicine, pharmaceuticals and food industries. In this project Silver-Chitosan coating on 316L Stainless steel by electrophoretic deposition was done to study the antibacterial property of Silver-Chitosan coating. First Silver was deposited on 316L Stainless steel at different supply voltages and at different deposition time. Then the prepared Silver coated samples were characterized according to their surface morphology and the samples on which silver was deposited in particulate form were chosen for chitosan coating. Then Chitosan was deposited on the chosen samples by electrophoretic deposition method. The prepared samples were then characterized for their surface morphology by FESEM technique and optical microscopy. The crystallinity of the samples were determined by XRD spectroscopy. The samples were then kept in a petri plate containing agar medium and the samples were exposed to E.Coli bacteria. The petri plate was then kept in an incubator overnight and the antibacterial property of the samples were studied.