Guo Juanli, Padilla Ricardo J, Ambrose Wallace, De Kok Ingeborg J, Cooper Lyndon F
Dental Research Center, School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Biomaterials. 2007 Dec;28(36):5418-25. doi: 10.1016/j.biomaterials.2007.08.032. Epub 2007 Sep 14.
It is widely accepted that implant surface factors affect the quality of the bone-to-implant interface. Recent additional treatments superimposed on moderately rough cpTitanium surface provide further enhancement of bone-to-implant contact. The aim of this study was to compare osteoinductive and bone-specific gene expression in cells adherent to titanium dioxide-grit blasted (TiO2) versus TiO2 grit blasted and HF treated (TiO2/HF) cpTitanium implant surfaces. MC3T3-E1 cells were grown in osteogenic supplements on the titanium disk surfaces for 1-14 days. Real-time PCR was used to measure RUNX-2, Osterix, and bone sialoprotein (BSP) mRNA levels. Implants were placed in rat tibia and, following harvesting at 1-7 days after placement, real-time PCR was used to measure RUNX-2, alkaline phosphatase (ALP), and BSP mRNA levels in implant adherent cells. In cell culture, RUNX-2 and Osterix levels were significantly increased (p<0.05) on the TiO2/HF surfaces as compared to the TiO2 and smooth surfaces through the cultural period, while BSP expression was elevated on both TiO2 and TiO2/HF surfaces when compared to a machined surface control. In cells adherent to implants retrieved from rat tibia, RUNX-2 mRNA levels were 2-fold and 8-fold greater on the TiO2/HF surfaces at 1-3 and 7 days following implantation. This was paralleled by significantly greater levels of ALP at 3 and 7 days and BSP mRNA at 7 days following implantation. As a marker of osteoinduction, the increased levels of RUNX-2 in cells adherent to the TiO2/HF surfaces suggest that the additional HF treatment of the TiO2 grit blasted surface results in surface properties that support adherent cell osteoinduction. In vivo assessments of implant adherent cell phenotypes provide further insight into the mechanisms affecting alloplast-tissue interactions.
植入物表面因素会影响骨与植入物界面的质量，这一点已被广泛接受。近期在中等粗糙度的商业纯钛表面进行的额外处理进一步增强了骨与植入物的接触。本研究的目的是比较附着于二氧化钛喷砂处理（TiO2）与二氧化钛喷砂和氢氟酸处理（TiO2/HF）的商业纯钛植入物表面的细胞中骨诱导和骨特异性基因的表达。MC3T3-E1细胞在成骨补充剂中于钛盘表面生长1至14天。采用实时聚合酶链反应（PCR）测量RUNX-2、osterix和骨涎蛋白（BSP）的信使核糖核酸（mRNA）水平。将植入物植入大鼠胫骨，在植入后1至7天取出，采用实时PCR测量植入物附着细胞中RUNX-2、碱性磷酸酶（ALP）和BSP的mRNA水平。在细胞培养中，与TiO2和光滑表面相比，TiO2/HF表面的RUNX-2和osterix水平在整个培养期均显著升高（p<0.05），而与机械加工表面对照相比，TiO2和TiO2/HF表面的BSP表达均升高。在从大鼠胫骨取出的植入物附着细胞中，植入后1至3天和7天，TiO2/HF表面的RUNX-2 mRNA水平分别高出2倍和8倍。植入后3天和7天ALP水平显著升高，7天BSP mRNA水平显著升高，情况与之相似。作为骨诱导的标志物，附着于TiO2/HF表面的细胞中RUNX-2水平升高表明，对TiO2喷砂表面进行额外的氢氟酸处理可产生支持附着细胞骨诱导的表面特性。对植入物附着细胞表型的体内评估为影响异体材料与组织相互作用的机制提供了进一步的见解。
