Biomimetic Electroconductive Hydrogels: Biologically Inspired Co-Networks of Polypyrrole and Poly(hydroxyethyl methacrylate) Containing Poly (Ethylene Glycol) and Phosphorylcholine for Implantable Biochips

Prof Anthony Guiseppi-Elie
Dow Chemical Professor of Chemical and Biomolecular Engineering,
Professor of Bioengineering and
Director, Center for Bioelectronics, Biosensors and Biochips
Clemson University, USA

Wednesday, December 12, 2007
10am to 11am

Aspiration Theatrette, Level 2M
The Matrix, 20 Biopolis Street, Biopolis

Abstract
Biologically-inspired, biomimetic hydrogels based on a 2-hydroxyethyl methacrylate (HEMA) cross-linked with tetraethylene glycol diacrylate (TEGDA) were molecularly engineered using two methacrylate-based monomers, poly (ethylene glycol) (200) monomethacrylate (PEGMA) and 2-methacryloyloxyethyl phosphorylcholine (MPC), to confer biocompatibility. PEG chains are known to prevent protein adsorption and PC is the head-group of the outer leaflet of mammalian cell membranes. 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. Biomimetic electroconductive hydrogels were prepared as co-networks by inclusion of bi-functional monomers that contain both a conducting polymer precursor and a photopolymerizable acryloyl functionality. These polymers are stimuli responsive materials that are of interest for the making of electroactuable drug release devices and implantable biosensors. Here we report the use of 2-methacryloyloxyethyl-4-(3-pyrrolyl)butanate to fabricate co-networks of polypyrrole within methacryloyl based hydrogels.

About the Speaker
Anthony Guiseppi-Elie is the Dow Chemical Professor of Chemical and Biomolecular Engineering, Professor of Bioengineering and Director of the Center for Bioelectronics, Biosensors and Biochips at Clemson University. He is also President and Scientific Director of ABTECH Scientific, Inc., a near-patient biomedical diagnostics company located in the Biotechnology Research Park, Richmond, Virginia. He holds the Doctor of Science degree in materials science and engineering from MIT, the Master of Science degree in chemical engineering from the University of Manchester Institute of Science and Technology (UMIST) and the Bachelor of Science degree (First Class Honors) with majors in Analytical Chemistry, Biochemistry and Applied Chemistry from the University of the West Indies (UWI). Prof. Guiseppi has spent 15 years in intrapreneurial and entrepreneurial industrial research and development with such companies as W. R. Grace and Co., Molecular Electronics Corporation, Ohmicron Corporation, and ABTECH Scientific. Prof. Guiseppi was a Visiting Scientist (‘95-‘96) in Biomedical Engineering in the School of Medicine at Johns Hopkins University before becoming a full professor at Virginia Commonwealth University in 1998. Tony is an Adjunct Professor of Chemistry at the University of the West Indies and has been an Adjunct Professor of Bioengineering at Cornell University and of Materials Science at Penn State University. His research interests are in engineered bioanalytical systems in the service of human health and medicine. Amongst his interests are: bioelectrochemistry and bioelectronic devices, implantable bioactive hydrogels, in vivo biosensors for trauma management, DNA biochips for biomedical diagnostics and prognostics. Prof. Guiseppi is a member of the editorial boards of the Journal of Bioactive and Compatible Polymers, NanoBiotechnology and Your World and sits on the recently comprised NIH NIBIB Study Section on Biomaterials and Biointerfaces. Prof. Guiseppi has published ca. 100 technical papers, 31 book or proceedings chapters and holds 8 patents. Prof. Guiseppi was the recipient of the 1999 SEAM Award from the Polymer Research Institute at Polytechnic University for his work on “…bio-technical properties and applications of electroactive polymers”. He is a recipient of the 2003 “Pioneers in Biomedical Engineering” Lecture Award from Purdue University, a lecturer in the MIT Program in Polymer Science and Technology and is a Fellow of the American Institute of Chemists (FAIC) and a Fellow of the American Institute for Medical and Biological Engineering (FAIMBE). At Clemson University, Prof. Guiseppi teaches materials science and engineering, biomolecular engineering, biosensors, and nanobiotechnology.