Zinc-Chitosan Composite Coating on 316LSS for Bone Tissue Engineering by Electrochemical Method

Abstract

316LSS and the alloys of 316LSS are generally used for the fabrication of osteo-synthetic and orthopedic implants. In this project chitosan was chosen as the polymer to be coated on the 316LSS sample as an effort to induce surface modification of the sample. Because of its biodegradable nature, unique and multidimensional structural properties, chitosan has been extensively investigated and explored in the field of regenerative medicine and bone tissue engineering. Chitosan also exhibits the properties of low immunogenicity that makes it suitable to get accommodated in the body fluids. The bone implants used to treat bone disorders or to carry out tissue repair are susceptible to infections caused by staphylococci, specifically Staphylococcus aureus. Hence, the development of better biological materials that provide antimicrobial activity in bone tissue engineering is required. In this project fabrication of Zinc-Chitosan coating on 316LSS by electrochemical method was done for bone tissue engineering. A layer of Zinc was electroplated first on 316LSS at different supply voltages and at different deposition times. Then the as prepared Zn coated samples were characterized for their surface morphology and the samples on which Zinc was deposited in a particulate form in selected area over the substrate surface in minute amounts were further chosen for Chitosan coating. Deposition of chitosan on Zn-coated 316LSS was carried out by EPD method. Thereafter, the as prepared implant surfaces were characterized for their surface morphology through FESEM, elemental composition through EDS and phase purity through XRD. The coated samples were further placed in a petri plate with agar medium and their surfaces were exposed to E.coli culture. The petri plate was then kept in an incubator for nearly 36 hours and the samples were then tested for their antibacterial properties.