Biocatalysis for Material Science and Drug Discoveries

ABSTRACTA novel biomimetic route for the synthesis of conducting homopolymers and copolymers from aniline, phenol, pyrrole and 3,4-ethylenedioxy-thiophene in the presence of a polyelectrolyte, such as polystyrene sulfonate (SPS) is presented. A poly(ethylene glycol) modified hematin (PEG-Hematin) and the enzyme horseradish peroxidase (HRP) were used to catalyze the copolymerization of different monomers. UV-vis, FTIR, XPS, TGA and electrical conductivity studies for all complexes indicated the presence of a stable and electrically conductive form of these polymers. Furthermore, the presence of a polyelectrolyte, such as SPS, in this complex provides a unique combination of properties such as processability and water-solubility. Additionally catechins, the active compounds found in green tea, were polymerized and found to exhibit very interesting anti-carcinogenic properties. Here we report a unique enzymatic approach for the synthesis of water-soluble poly(catechins) with enhanced stability and potent anti-proliferative effects on human cancer cells in vitro. Various stereoisomers of catechin [(+), (-), (±)] and (-)-epicatechin have been biocatalytically polymerized using HRP in ethanol/buffer mixtures. This one-pot biocatalytic polymerization is carried out in ambient conditions yielding water-soluble poly(catechins). These synthesized poly(catechins) were tested for their growth inhibitory properties using a variety of normal and cancerous human epithelial cell lines. The poly(catechins) exhibit statistically significant greater growth inhibitory effects when compared to the monomers and exhibited specificity, inhibiting the growth of breast, colorectal and esophageal cancer cells while having little effect on normal epithelial cell growththus achieving a high therapeutic ratio. The synthesis, characterization and the growth inhibitory effects of these novel water-soluble poly(catechins) will also be presented.