SURFACE MODIFICATION STRATEGIES FOR INHIBITING BACTERIAL COLONIZATION AND ENCRUSTATION IN URINARY CATHETER APPLICATIONS

Abstract

This thesis aims to develop antibacterial coatings for urinary catheters to inhibit bacterial colonization and encrustation, in order to reduce urinary tract infections and catheter blockage. The first antibacterial coating developed was based on surface immobilized carboxymethyl chitosan. The second coating was based on the integration of an antifouling zwitterionic polymer and bactericidal chitosan derivative with quaternary ammonium group. These coatings effectively reduced bacterial colonization on the surface, but in order to kill the planktonic urease-producing bacteria which cause encrustation, release of an antimicrobial agent at an adequate concentration is required. Thus, two bifunctional coatings which are antifouling and capable of releasing an antimicrobial agent in a sustained manner were also developed. The first is a bilayered coating comprising an antimicrobial agent (4-amide-piperidine-C12)-loaded hydrogel layer and an outer Pluronic-zwitterionic copolymer layer. The second is a multilayered coating with silver loaded in alternate layers and an outermost zwitterionic polymer layer.