| AVS 54th International Symposium | |
| Biomaterial Interfaces | Tuesday Sessions |
| Session BI-TuP |
| Session: | Biomaterials Interfaces Poster Session |
| Presenter: | M.A. Cole, University of South Australia |
| Authors: | M.A. Cole, University of South Australia H. Thissen, CSIRO Molecular and Health Technologies, Australia N.H. Voelcker, Flinders University, Australia H.J. Griesser, University of South Australia |
| Correspondent: | Click to Email |
Surface modification of biomedical and biotechnological devices using thin polymeric coatings is a popular method employed to alter the interactions of synthetic materials with biomolecules and cells from surrounding biological media and environments. Advancements in this field have been made largely from an interdisciplinary approach combining surface modification and polymer science with biomaterials science and biological studies. Recent research into stimuli-responsive or switchable materials has focused on means to control protein-material and cell-material interactions with respect to directing the spatial location, temporal location and biological function of biomolecules. Controlling the interfacial interactions of biological components is of interest for a wide range of biomedical/biotechnological applications including microarrays, biosensors, drug delivery, cell sheet engineering and ‘lab on a chip’ devices. As part of ongoing research we report our findings on the grafting and properties of stimuli-responsive coatings incorporating poly(N-isopropylacrylamide) (pNIPAM). Thin films of pNIPAM were prepared via ‘grafting to’ and ‘grafting from’ techniques and investigated at temperatures above and below the lower critical solution temperature (LCST) of approximately 32 °C. Switching of coatings between hydrated and collapsed states below and above the LCST was investigated with respect to the degree of change in phase transition and the ability to induce protein adsorption. Surface analysis was carried out using X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and time of flight secondary ion mass spectrometry (ToF SIMS). Adsorption of model proteins, lysozyme and bovine serum albumin were investigated using a quartz crystal microbalance (QCM), optical waveguide lightmode spectroscopy (OWLS), TOF SIMS, and AFM. Results from switching and protein adsorption experiments show the transformation of pNIPAM coatings between low fouling (protein resistant) and fouling (protein adsorbent) states. Colloid probe force analysis of pNIPAM coatings reveal considerable changes in protein-pNIPAM interactions at different temperatures. The present study is expected to assist the development of switchable coatings for biomedical and biotechnological applications.