Improvement Of Biodegradable Biomaterials For Use In Orthopedic Fixation Devices

Abstract

Current orthopedic internal fixation devices, such as pins and screws, are typically made from metals and have a long list of complications associated with them. Most notably, complications such as infection or decreased wound healing arise from revisional surgeries needed to remove the used hardware. A new class of fixation devices is being produced from biodegradable biomaterials to eliminate the need for revisional surgery by being naturally broken down in the body. While currently available polymers lack the necessary mechanical properties to match bone strength, the incorporation of small amounts of hydroxylated nanodiamonds has been proven to increase the mechanical properties of the native polymer to better resemble native bone. Additionally, modern polymers used in biodegradable fixation devices have degradation rates that are too slow to match the growth of new bone. Poly-(D, L)-lactic-co-glycolic acid (PDLG) incorporated with hydroxylated nanodiamonds has not only been proven to start out stronger, but then also helps the polymer degrade faster when compared to the pure polymer in vivo and prevents effusion of the polymer into the surrounding environment. Nanodiamond incorporation is accomplished via solid state polycondensation of PDLG to create a uniform material with increased mechanical properties, faster degradation rates, and enhanced calcification when tested in simulated body fluid.