Synthesis and mechanical properties of conductive composite polylactic acid/polyaniline scaffold for potential tissue engineering

Abstract

This thesis reports a new composite scaffold material that is conductive and porous made from degradable polylactic acid (PLA) and conducting polyaniline (PANI) which has the potential for use in promoting tissue regeneration. The conductive scaffold was successfully prepared using a simple yet effective method known as freeze extraction method. The doped PANI was synthesised using conventional method of oxidative chemical polymerization. The electrical percolation state was successfully obtained at 3 wt% of PANI inclusion and reached at useable conductivity level for tissue engineering application at 4 wt% PANI, 2.91 x 10-3 Scm-1. 4 wt% inclusion of PANI was justified as the best PLA/PANI composite scaffold because it met the criterion as an electro-responsive material where the conductivity achieved was higher than 10-3 Scm-1. It is also much suitable material in the regeneration of skin tissue (fibroblast) because the mean pore size achieved was at 35.82 µm and optimum tensile strength at 3.08 MPa. The UV-spectrum of the conductive scaffold displayed transition peaks of PANI indicating the PANI was still in its conducting doped state inside the scaffold. Incubation for 24 weeks for in-vitro degradation revealed that the PANI component delayed the degradation of PLA. Preliminary bioactivity test results indicated that the doping agent able to form chelate at the scaffold surface and this could assist in the formation of in-vitro apatite during the biomimetic immersion.