POLY 252 |
| Biomimetic hydrogels based on a 2-hydroxyethyl methacrylate (HEMA) crosslinked with tetraethylene glycol diacrylate (TEGDA) were molecularly engineered using two methacrylate-based monomers, poly (ethylene glycol) (200) monomethacrylate (PEGMA) and 2-methacryloyloxyethyl phosphorylcholine (MPC), and investigated for their in vitro biocompatibility. PEGMA and MPC were incorporated at varying mole fractions of 0.0 - 0.5 mol % and 0 – 10 mol %, respectively. The in vitro biocompatibility was studied using fibroblast proliferation and viability assays, human aortic muscle endothelial cytotoxicity assays, protein (fibronectin, collagen and laminin) adsorption, as well as the effect of extended hydration on the emergent hydrophilicity as measured by dynamic contact angle. Properties were investigated as a function of engineered molecular composition. Hydrogels exhibited an increase in the percent hydration (93.8 %) with an increase in the MPC content (up to 10 mol %) in a 3 mol % cross-linked p(HEMA) formulation. PEG had a smaller influence on hydration than MPC. Fluorescence intensity of FITC-dye tagged fibronectin (0.0 through 1.0 ng/ml ) adsorbed at 25 °C onto the various hydrogel substrates conformed to the Langmuir adsorption isotherm. The Langmuir parameters, Kd and Qm, quantitatively confirmed the reduction in protein adsorption with hydrogel hydration levels in D.I. water over periods of up to 5 days and also paralleled the increase in the MPC content. Cytotoxicity studies produced greater than 80% viability for all the hydrogel formulations and fibroblasts retention assays revealed that the higher the MPC content the greater the cell retention capacity of the hydrogel (R2 = 89%). |
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Polymers in Biosensors and Biochips
8:30 AM-11:50 AM, Monday, 11 September 2006 San Francisco Marriott -- Salon 12/13, Oral
Division of Polymer Chemistry |