Projection-based 3D printing of multichannel poly(caprolactone) methacrylate nerve guidance conduit for peripheral nerve regeneration

Abstract

The repair of peripheral nerves and the restoration of the innervated function are significantly challenging for clinicians and researchers because of their limited self-regenerative capacity. Although nerve guidance conduits (NGCs) are a promising alternative, several challenges such as material selection, structural design, and fabrication methods remain to be addressed. At present, commercially available NGCs have a simple hollow structure, constrained by the use of regulatory-approved materials and conventional fabrication methods. This study used an advanced method for manufacturing NGCs by employing projection-based 3D printing to fabricate a series of 1-, 4-, and 7-channel conduits from poly(caprolactone) methacrylate (PCLMA). These were evaluated on the basis of morphologic and mechanical characteristics, through the in vitro culture of rat Schwann cells 96 and in vivo by using a 10-mm-gap repair model in Sprague-Dawley rats. The 4- and 7-channel NGCs exhibited considerably better nerve repair efficiency than the 1-channel NGCs. This observation suggests that NGCs with multiple channels have greater superiority in guiding nerve regeneration. The study offers a technological paradigm for precisely manufacturing biocompatible materials and serves as a valued reference for future advancements in more intricate NGC designs, larger scaffold dimensions with biodegradability, and more extended implantation research.