Silver Nanocomposite Material as Antibacterial Coating on Indwelling Medical Devices-Based Biomaterials

Abstract

The most common type of adverse events in healthcare in Canada reported by the Canadian Institute for Health Information (CIHI) are nosocomial infections. Amongst nosocomial infections, implant associated infections have been reported to be most common. Despite having the implantation surgeries carefully performed, a small, but still considerable number of devices gets colonized by bacteria resulting in implant associated infections and/or surgical site infections. The patients are then started on high dose antibiotics, which if ineffective, is followed by reimplantation surgeries that leads to long hospital stays and detrimental effects in their lives. Due to this, an alternative to antibiotics is required which could prevent and/or treat bacterial colonization on implants. The main objective of this thesis was to demonstrate the effectiveness of an antimicrobial based CLKRS peptide capped silver nanoparticle coating on a metallic and polymeric based biomaterial used in various implantable medical devices. The CLKRS peptide capped silver nanoparticle formulation was specifically engineered and tested for its antibacterial and antibiofilm properties. Silver nanoparticles were synthesised by photochemical reduction of silver ions upon photocleavage of the photoinitiator I-2959. The metal nanostructure surfaces were protected with the CLKRS peptide and tested on planktonic and biofilms of P. aeruginosa, S. aureus and S. epidermidis. The bacterial quantification was done by survival colony counting. The cytotoxicity of the silver nanoparticle formulation was also tested on human dermal fibroblast, mouse bone marrow derived macrophages, and human epithelial cells by cell proliferation assay. Results show the formation of a nanometric layer of nanosilver on the surface of the material inhibiting the growth of bacteria and eradicating pre-existing biofilms with no significant cell toxicity suggesting the prepared formulation could be a useful tool in preventing and controlling infections on implants during surgery and post implantation. This technology thus could serve as an alternative therapy for surgical site infections and/or implant associated infections.