Mechanochemical Processing of Thermoplastic Nanocomposites for Regenerative Orthopedic Surgery

J. Connell
OrthoMend Research Inc, Pennsylvania, United States

Keywords: Regenerative medicine, trauma, bone fixation, Fracture,orthopedic

Current degradable orthopedic fixation devices, such as screws or pins, fail to facilitate tissue integration during healing. We propose a novel combination of processing methods to enhance the tissue integration capability of degradable orthopedic fixation devices. The provision of open pores in devices used to affix reconstructed hard tissues would allow for local cells to infiltrate during the healing process. Any porous structure is inherently weakened in comparison to its monolithic peer; thus, the matrix materials must be made more resilient to keep the device from becoming friable. Our processing methods aim to improve degradable surgical fixation devices both through the inclusion of a porous morphology as well as processing changes and additives to regain mechanical integrity. While biomimetic pores facilitate cellular infiltration, the addition of open pores significantly reduces the bulk stiffness. Carbon nanomaterials have been used to improve on the mechanics and surface chemistry of the polymer matrix material, The addition of minute amounts of functionalized nanodiamond by cryogenic milling and solid state polycondensation of poly((D,L)lactide-coglycolide) and hydroxyl-functionalized detonation nanodiamonds remedied the brittle failure of the material. This composite has demonstrated increased cytocompatibility, as analyzed by enhanced adhesion and proliferation of 7F2 osteoblasts cultured on our biomaterial.