Development of new fluoropolymer surface chemistries for biomaterial applications: Peptide attachment, cell adhesion, and biomineralization studies

The research described in this dissertation focuses on the continued development of novel, modified fluoropolymer surfaces with an emphasis on applications to biomaterials and tissue engineering. In this work, a radio frequency glow discharge (RFGD) plasma is used as the primary basis to functionalize fluoropolymer surfaces, continuing on the foundation developed in previous work from this research group. This modification provides reactive sites on the fluoropolymer surface for the covalent attachment of additional chemical species. X-ray Photoelectron Spectroscopy (XPS), Attenuated Total Reflectance-Fourier Transform Spectroscopy (ATR-FTIR), fluorescence spectroscopy, and contact angle are used to characterize the surface modifications.; Fluoropolymers possess characteristics such as low surface energy, good thermal and chemical resistance, hydrolytic stability, and electrical properties, making them an attractive class of polymers for biomaterial applications. Cellular attachment to a surface can be induced by chemically modifying the surface to control adsorption of proteins or by covalently binding minimal peptide sequences that are recognized by cell surface receptors, thus control of polymer surface properties represents a reasonable approach to achieve the desired biological response.; The first area of investigation discusses the silanization of hydroxylated fluorinated ethylene propylene (FEP) and subsequent chemical modification to produce surfaces with amine (-NH₂) and carboxyl (-COOH) functional groups available for peptide attachment by either the C- or N-termini, respectively. The goal here was to both increase surface wettability and surface peptide coverage with respect to previous methods developed by this research group.; The second area of investigation compares the cellular adhesion characteristics of primary respiratory epithelial cells and A549 lung carcinoma cell line on surfaces incorporating simple functional groups (-OH, -NH₂, -COOH) and minimal cell recognition sequences (CDPGYIGSR and DGEA) in serum free media. Model systems utilizing primary cells represents an increased level of complexity necessary for investigating cellular responses to synthetic surfaces.; The final area of investigation utilizes modified fluoroploymer substrates to examine the role of simple functional groups (-NH₂, -COOH) in surface induced biomineralization. This study showed that the induction period, growth kinetics, and crystal surface morphology were affected by the surface functional group for both octacalcium phosphate (OCP) and hydroxyapatite (HAP).