(Dr. Robert Guldberg, advisor)
"Biodegradable Implants Produced Using Fiber Coating Technologies"
Methods involving fiber reinforcement were investigated in order to produce biodegradable implants. One goal was to develop biodegradable fixation pins with higher mechanical properties than those currently in existence. Another primary goal was to develop and characterize porous biodegradable polymer scaffolds with novel microarchitecture using microcomputed tomography (micro-CT) and mechanical testing. Pins produced using bicomponent PLA/PLDL fibers as well as glass-reinforced PLDL pins were tested to determine bending properties. The bicomponent pultruded pins had inferior initial properties than SR-PLLA Bionx SmartPins. The glass-reinforced pins had comparable initial properties, but after exposure to an aqueous environment over time, properties decreased. Improvement of interfacial strength may provide enhanced properties. Porous 3D PLDL scaffolds with novel microarchitecture were produced and characterized microarchitecturally and mechanically. The microarchitecture was designed with two components: axially oriented channels as well as surrounding microporosity. These scaffolds possessed initial compressive mechanical properties comparable to trabecular bone. In addition, scaffolds retained about 90% of initial strength and 80% of initial modulus after 16 weeks in aqueous environmental conditions. Further testing, especially more extensive fatigue testing, is necessary to fully assess the ability of these scaffolds to serve as bone replacement materials.