Cationic Metallocene-Containing Biomaterials For Antimicrobial Applications

Metal-containing polymers or metallopolymers, are one of the major classes of polymers which stand out independently because of a unique combination of organic and inorganic components in one macromolecular system. Among the variety of metallopolymers, metallocene-containing polymers have been widely utilized for applications ranging from electrochemical sensors to templates for advanced inorganic catalysts to battery materials, due to their unique physicochemical properties. This dissertation is focused on the synthesis, characterization, and application of cationic metallocene-containing polymeric materials. Cationic-cobaltocenium was grafted in various inorganic nanoparticles using polymerization techniques such as reversible addition-fragmentation chain transfer polymerization. In Chapter 1, the overall background of metallopolymers, antimicrobial polymers and modification of nanoparticle polymerization methods is included. Chapter 2 focuses on the study of electrostatic charge on the relative affinity and comparison of the relative binding strength of a cobaltocenium-containing polyelectrolyte. The nature and relative strength of intermolecular interaction between cationic polyelectrolytes and anionic probes were investigated. Chapter 3-4 reports the preparation of inorganic silica and iron oxide nanoparticles grafted with charged cobaltocenium-containing metallopolymers by surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization. In Chapter 5, cobaltocenium-containing polymers were coated on gold nanoparticles by a grafting-to mechanism. β-lactam antibiotic like penicillin-G were then conjugated with all the nanoparticles by ion-pairing between the cationic cobaltocenium moiety in the nanoparticles and carboxylate anions of antibiotics. Such bio-conjugated nanoparticles not only reduced the activity of β-lactamase but effectively lysed both Gram-positive and Gram-negative bacterial cells. All these nanoparticles were characterized and subjected for antimicrobial evaluation against a range of bacteria and biocompatibility with mammalian cells