首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Nanoscale Confinement Controls the Crystallization of Calcium Phosphate: Relevance to Bone Formation
Authors:Bram Cantaert  Dr Elia Beniash  Prof Fiona C Meldrum
Institution:1. School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT (UK), Fax: (+44)?113‐343‐6565;2. Department of Oral Biology, School of Dental Medicine, McGowan Institute for Regenerative Medicine, University of Pittsburgh, 3501 Terrace Street, 15261 PA (USA)
Abstract:A key feature of biomineralization processes is that they take place within confined volumes, in which the local environment can have significant effects on mineral formation. Herein, we investigate the influence of confinement on the formation mechanism and structure of calcium phosphate (CaP). This is of particular relevance to the formation of dentine and bone, structures of which are based on highly mineralized collagen fibrils. CaP was precipitated within 25–300 nm diameter, cylindrical pores of track etched and anodised alumina membranes under physiological conditions, in which this system enables systematic study of the effects of the pore size in the absence of a structural match between the matrix and the growing crystals. Our results show that the main products were polycrystalline hydroxapatite (HAP) rods, together with some single crystal octacalcium phosphate (OCP) rods. Notably, we demonstrate that these were generated though an intermediate amorphous calcium phosphate (ACP) phase, and that ACP is significantly stabilised in confinement. This effect may have significance to the mineralization of bone, which can occur through a transient ACP phase. We also show that orientation of the HAP comparable, or even superior to that seen in bone can be achieved through confinement effects alone. Although this simple experimental system cannot be considered, a direct mimic of the in vivo formation of ultrathin HAP platelets within collagen fibrils, our results show that the effects of physical confinement should not be neglected when considering the mechanisms of formation of structures, such as bones and teeth.
Keywords:amorphous calcium phosphate  biomimetic synthesis  biomineralization  collagen  hydroxapatite
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号