Nayab Saima N, Jones Frances H, Olsen Irwin
Division of Biomaterials and Tissue Engineering, University College London, Eastman Dental Institute, 256 Gray's Inn Road, London WC1X 8LD, United Kingdom.
J Biomed Mater Res A. 2007 Nov;83(2):296-302. doi: 10.1002/jbm.a.31218.
The modification of titanium (Ti) surfaces by ion-implantation has previously been reported to enhance osseointegration in vivo. However, the mechanisms underlying the apparently improved biocompatibility of these novel implant materials are unknown. The aim of this study is, therefore, to determine the precise effects of calcium ion-implanted Ti on the functional activity of bone cells in vitro. Flow cytometry (FCM) and the reverse transcriptase polymerase chain reaction (RT-PCR) were used to measure the response of bone-derived cells to key bone-associated components, including alkaline phosphatase (ALP), bone morphogenetic protein receptor-1B (BMPR-1B), bone sialoprotein (BSP), osteonectin (ON), and osteopontin (OPN). FCM analysis showed that BMPR-1B, BSP and particularly OPN were significantly up-regulated in MG-63 cells cultured on Ca-implanted Ti compared with control nonimplanted Ti. Moreover, the effects of this novel Ca-Ti surface were found to be mediated, at least partly, via gene activation, since RT-PCR demonstrated the presence of notably elevated levels of OPN mRNA transcripts in the MG-63 cells. These findings thus show that Ti surfaces implanted with Ca ions can enhance the expression of certain bone-associated components in vitro, and suggest that this effect could be the cause of the potential benefit of this material on bone in vivo.
此前有报道称，通过离子注入对钛（Ti）表面进行改性可增强体内骨整合。然而，这些新型植入材料生物相容性明显改善的潜在机制尚不清楚。因此，本研究的目的是确定钙离子注入的钛对体外骨细胞功能活性的精确影响。采用流式细胞术（FCM）和逆转录聚合酶链反应（RT-PCR）来测量骨源细胞对关键骨相关成分的反应，这些成分包括碱性磷酸酶（ALP）、骨形态发生蛋白受体-1B（BMPR-1B）、骨唾液蛋白（BSP）、骨连接蛋白（ON）和骨桥蛋白（OPN）。FCM分析表明，与未植入的对照钛相比，在植入钙的钛上培养的MG-63细胞中，BMPR-1B、BSP尤其是OPN显著上调。此外，发现这种新型钙钛表面的作用至少部分是通过基因激活介导的，因为RT-PCR证明MG-63细胞中OPN mRNA转录物水平明显升高。这些发现表明，注入钙离子的钛表面可在体外增强某些骨相关成分的表达，并表明这种效应可能是该材料对体内骨骼潜在益处的原因。
