Liver tissue engineering via hyperbranched polypyrrole scaffolds

Synthesis of novel hyperbranched aliphatic polyester/polypyrrole (HAP-PPy) is reported to incorporate electroactive PPy units and biodegradable ester units into one macromolecular configuration. Electroactive nanofibers were prepared from HAP-PPy blended with polycaprolactone. HAP-PPy exhibited redox activity as detected by cyclic voltammetry, and thereby pyrrole units maintained their electroactivity even after incorporation into copolymer framework. Resulting scaffolds possessed porous structure (60–90 nm) with large surface area, electrical conductivity (0.003–0.008 S cm−1). These imitated natural microenvironment of extracellular matrix (ECM) to regulate cell attachment, proliferation, and differentiation. In vitro cytocompatibility studies indicated that nanofibers were nontoxic to human HEP G2 cells.