Date of Award
Doctor of Philosophy (PhD)
Anti-biofouling chemistry, Surface engineering, Molecular inhibition, Protein adsorption, Mammalian cell adhesion, Biofilm formation
The common theme that binds together all the chapters in this dissertation is anti-biofouling chemistry. By utilizing tools of surface engineering and molecular inhibition, a hypothesis driven, systematic approach of controlling the different forms of biofoulings such as protein adsorption, mammalian cell adhesion and biofilm formation is presented. Chapter 1 provides a brief introduction about topics relevant for understanding the studies presented in subsequent chapters. Chapter 2 reports the synthesis of enantiomerically pure alkanethiols that terminate with different stereoisomer's of sugar alcohols, and the effect of chirality of these polyol-terminated self-assembled monolayers (SAMs) on resisting protein adsorption.
Chapter 3 and 4 presents the results on confining adhered mammalian cell (Swiss 3T3 albino fibroblasts) and bacterial (Escherichia coli) biofilm respectively, within micrometer sized cell adhesive patterns of methyl-terminated SAMs, surrounded by bioinert chiral polyol-terminated SAMs. Interestingly, SAMs presenting racemic mixture of enantiomeric alkanethiols were found to confine the adhered mammalian cells or biofilm within the micrometer-sized patterns longer than the SAMs presenting either enantiomer. Chapter 5 presents the synthesis of chiral polyol-terminated alkanephosphonic acids to form SAMs on surface of native metal oxides, particularly TiO2 and Fe3O4, for evaluating the ability of these alkanephosphonate SAMs on TiO2 to resist the adhesion of mammalian cells (Swiss 3T3 albino fibroblasts) and on Fe3O4 to solubilize Fe3O4 (magnetite) nanoparticles in aqueous media. Another approach of controlling biofouling due to biofilm formation is to develop inhibitors for a class of organic molecules called autoinducers secreted by bacteria, which are responsible for regulating bacterial group behavior such as biofilm formation. Chapter 6 reports the synthesis of derivatives of a class of molecules called brominated furanones, which are known to inhibit biofilm formation in E. coli. Chapter 7 reports the synthesis of novel squarate based molecules named squarylated homoserine lactones (SHLs), which are structural mimics of the bacterial autoinducer molecules called acylated homoserine lactones (AHLs). The synthesized brominated furanone derivatives and SHLs were found to be non-toxic to E. coli and were able to inhibit the biofilm formation by the bacterium.
Bandyopadhyay, Debjyoti, "Controlling Biofouling by Surface Engineering and Molecular Inhibition" (2011). Chemistry - Dissertations. Paper 180.