Effect of bimodal pore structure on the bioactivity of poly(lactic-co-glycolic acid)/poly(γ-glutamic acid)/Pluronic 17R4 nerve conduits

Nerve conduits have been paid attention to as a useful technique for bridging the gap between damaged peripheral nerve stumps. In particular, the development of nerve conduits with a higher porosity and surface area is necessary for providing the conditions needed for nerve tissue regeneration. Here we fabricated poly(lactic-co-glycolic acid)/poly(γ-glutamic acid)/Pluronic 17R4 nerve conduits containing three-dimensional bimodal pore structures using the thermally induced phase separation technique. The dope composition of polymers and separation temperature were found to significantly affect the fabrication of the nerve conduits; the optimum dope composition was found to be 58:19:23 at a concentration of 26 w/v%, and the optimum separation temperature was 40 °C. The results of bioactivity tests demonstrated that PP40 fabricated under the optimum conditions promoted more rapid Schwann cell proliferation than other nerve conduits because of their three-dimensionally interconnected bimodal pore structures, large surface area, and hydrophilicity. Our results suggest that neve conduits with bimodal open pore structures could be used as nerve graft substitutes for nerve regeneration.