Bioactivating electrically conducting polypyrrole with fibronectin and bovine serum albumin

Electrically conducting polypyrrole (PPy) and its composite materials are useful in interfacing electrical components and cells or living tissue. In recent years, significant efforts have been made to bioactivate PPy by incorporating biomolecules. The main objective of this work was to chemically bioactivate PPy particules by incorporating fibronectin (IN) and bovine serum albumin (BSA). Modified PPy particles were synthesized through a water-in-oil emulsion polymerization. XPS and FTIR confirmed the presence of biomolecules on the PPy particles, and the surface morphology was observed by SEM. A four-point probe was used to measure the conductivity of the newly synthesized PPy particles, which was in the range of 10(-1) S cm(-1). Conductive biodegradable membranes were prepared with 5 and 10% (wt/wt) PPy to poly(L,L-lactide) (PPy/PLLA). The contact angles of each synthesized membrane were similar to 75 degrees, Supporting their usefulness for cell culture. The cultured human skin fibroblasts demonstrated normal morphology and significantly higher adhesion and spreading on the PPy/PLLA similar to FN membrane than on the unmodified PPy/PLLA membrane. On the other hand, the PPy/PLLA similar to BSA membranes showed decreased cell adhesion. Bioactivated PPy may be useful in tissue engineering to fabricate conducting biodegradable scaffolds with either improved or reduced cell adhesion properties for various cell culture and hi vivo applications. (C) 2009 Wiley Periodicals, Inc. J Biomed Mater Res 92A: 221-231, 2010