Experimental and theoretical investigation of the role of nanofibrous topography feature size on adhesion of Candida albicans

Abstract

Biofilm formation on medical devices is responsible for a substantial portion of healthcare associated infections with approximately 99,000 deaths and estimated financial burden of $28-$45 billion annually. Given the long-standing challenges of biofilm eradication, physical and chemical surface modifications to prevent biofilm formation from the early adhesion stage, continue to gain momentum. Nanoscale structural features, ubiquitous in both natural and synthetic surfaces, are increasingly recognized to have wide-ranging effects on microorganism adhesion and biofilm development. In this thesis, bio-inspired nanofiber-coated polystyrene surfaces were developed to systematically investigate how highly ordered surface nanostructures (200nm-2000nm in size) impact adhesion and proliferation of model fungal pathogen, Candida albicans. A theoretical model for cell-textured surface interaction was also developed using thermodynamic principles to demonstrate that single cell adhesion to surface can be used to describe the population behavior. The trend for adhesion density of C. albicans on nanofiber-textured surfaces of varying diameters correlates with our theoretical finding of adherent single-cell energetic state. Findings from this thesis can be used for enhanced ab initio design of antifouling surfaces for medical applications and beyond. We demonstrate a successful prototypical example of reduction in biofilm formation by optimally designed nanofiber coating of urinary catheters.