Polymer Strategies in Musculoskeletal Tissue Engineering

Over one million surgical procedures are performed each year to treat bone defects with an associated medical cost over 5 billion dollars. Current procedures are fraught with problems that limit clinical success from fixation challenges in osteoporotic bone to replicating form factor in craniomaxillofacial reconstruction to infection control in traumatic injuries. Each indication requires a tailored strategy to restore function and guide regeneration. Our laboratory specializes in the development of polymeric biomaterials that meet the design criteria of each regeneration strategy. One particular area of interest is the treatment of fractures using an injectable, bone void filler. Current bone cements do not adequately support bone healing and lead to poor clinical outcomes. Our laboratory has developed a novel emulsion templating methodology to generate injectable, high porosity bone void fillers that cure to rigid foams at body temperature with compressive properties in the range of trabecular bone. We have enhanced the regenerative capacity of these synthetic grafts by mixing the emulsion with autograft particles. Recently, we have utilized this biomaterial platform to develop emulsion inks for 3D printing. Emulsions inks are rapidly cured after deposition by constant UV irradiation to form rigid constructs with interconnected porosity in a method we term Cure-on-Dispense printing. 3D printed constructs benefit from the tunable pore structure of emulsion-templated materials and the fine control over complex geometries of 3D printing that is not possible with traditional manufacturing techniques. A cell-releasing hydrogel was then developed to provide osteogenic potential and enhance the regeneration of these 3D printed scaffolds. Finally, we have utilized advanced electrospinning techniques to create bone wraps that eradicate infection and enhance vascularization. Collectively, this work highlights the versatility of polymer engineering to design tissue engineering scaffolds to meet clinical needs.