Biologic augmentation of polymer scaffolds for bone repair

摘要

The major clinical challenges in bone repair include largesegmental defects, fracture non-unions, spine fusion, andbone-soft tissue integration. Although the use of BMPs isincreasing rapidly, bone grafting remains the current clinicalstandard for osseous reconstruction. Autografts, however,have several disadvantages including limited available tissuefor transplantation, lack of structural integrity to withstandfunctional loads, and significant patient morbidity at the siteof harvest. As a result of these limitations, allogeneic boneand synthetic scaffold materials have increasingly been usedas substitutes for autografts over the past 20 years. Allograftsprovide initial structural integrity but suffer from reducedbioactivity and often fail to fully revascularize and remodel,resulting in a high refracture rate 1-2 years after implanta-tion1,2. Although possible immunogenicity and the lowporosity of structural allografts may contribute to poor clin-ical outcomes, recent evidence suggests that the absence ofviable cells is a critical factor in allograft failure3. Theseproblems have led to the search for improved methods tostimulate bone repair, including tissue engineering strategiesthat augment porous biomaterial