Development of nanocomposites for bone grafting

This article reviews nanocomposites focusing on their impact and recent trends in the field of bone grafting. Although autogenous- and allogeneic-bone grafts have been used for a long time in bone therapies, there is still a donor shortage and infection risk. As an alternative, synthetic biomaterials have been developed and clinically used as bone grafts, but most of them differ substantially from natural bone either compositionally or structurally. It remains a great challenge to design an ideal bone graft that emulates nature's own structure. Owing to the composition and structural similarity to natural bone, most of the current investigations involve the use of nanocomposites, particularly hydroxyapatite/collagen system, as promising bone grafts, but it is surprising that none of the reports review the rationale and design strategy of such nanocomposites in detail for the benefit of researchers. Accordingly, this article addresses the state-of-the-art of those nanocomposites and provides suggestions for future research and development. This review provides an overview of the nanocomposite strategy of bone, bone grafting, synthetic approaches to bone structure, development of nanocomposites from the conventional monolithic biomaterials, and recently developed processing conditions for making nanocomposites. The review is expected to be useful for readers to gain an in-sight on the state-of-the-art of nanocomposites as a new class of synthetic bone grafts. (c) 2005 Elsevier Ltd. All rights reserved.