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 vitrocytocompatibility studies indicated that nanofibers were nontoxic to human HEP G2 cells.