Effects of zinc-substituted nano-hydroxyapatite coatings on bone integration with implant surfaces

Objective:The purpose of this study was to investigate the effects of a zinc-substituted nano-hydroxyapatite(Zn-HA) coating,applied by an electrochemical process,on implant osseointegraton in a rabbit model.Methods:A Zn-HA coating or an HA coating was deposited using an electrochemical process.Surface morphology was examined using field-emission scanning electron microscopy.The crystal structure and chemical composition of the coatings were examined using an X-ray diffractometer(XRD) and Fourier transform infrared spectroscopy(FTIR).A total of 78 implants were inserted into femurs and tibias of rabbits.After two,four,and eight weeks,femurs and tibias were retrieved and prepared for histomorphometric evaluation and removal torque(RTQ) tests.Results:Rod-like HA crystals appeared on both implant surfaces.The dimensions of the Zn-HA crystals seemed to be smaller than those of HA.XRD patterns showed that the peaks of both coatings matched well with standard HA patterns.FTIR spectra showed that both coatings consisted of HA crystals.The Zn-HA coating significantly improved the bone area within all threads after four and eight weeks(P<0.05),the bone to implant contact(BIC) at four weeks(P<0.05),and RTQ values after four and eight weeks(P<0.05).Conclusions:The study showed that an electrochemically deposited Zn-HA coating has potential for improving bone integration with an implant surface.

大鼠骨髓间充质干细胞和成骨细胞在钛表面掺锶羟基磷灰石涂层上的成骨研究

目的：本研究旨在比较体外三种类型钛表面对促进成骨的作用：掺锶羟基磷灰石（Sr-HA）涂层表面．纳米HA涂层表面以及无涂层的粗糙表面。材料和方法：通过电化学沉积方法将Sr-HA和HA沉积于粗糙的钛表面上。在Sr-HA涂层、HA涂层和无涂层的粗糙钛表面上进行MC3T3-E1前成骨细胞和小鼠骨髓间充质干细胞培养，在不同时间点测定细胞的黏附、增殖、存活、分化和矿化结节形成。结果：对比于无涂层的粗糙钛表面和纳米HA涂层表面，通过简单的电化学沉积处理，Sr-HA涂层明显提高了小鼠骨髓间充质干细胞和MC3T3-E1细胞黏附、铺展，碱性磷酸酶活性和细胞外基质钙矿化。结论：这项研究表明．通过电化学沉积产生的掺锶纳米羟基磷灰石涂层Sr-HA提高了微粗糙钛表面的骨传导性。

Fluorescence microscopic analysis of bone osseointegration of strontium-substituted hydroxyapatite implants

The purpose of this study was to analyze the effect of strontium-substituted hydroxyapatite (Sr-HA) on bone osseointegration of the implants using fluorescence microscopy. We allocated 20 implants to two groups: Sr-HA group and HA group. Electrochemically deposited HA and Sr-HA coatings were applied onto the implants separately. All the implants were inserted into femur bone of rabbits. Oxytetracycline hydrochloride, alizarin-complexon, and calcein green were respectively administered 7, 28, and 46 d after the implantation. After eight weeks, femurs were retrieved and prepared for the fluorescence microscopy observation. We analyzed the bone mineral apposition rates (MARs), bone area ratios (BARs), and bone to implant contact (BIC) of the two groups. Fluorescence microscopic observation showed that all groups exhibited extensive early peri-implant bone formation. The MAR of the Sr-HA group was greater than that for pure HA from 7 to 28 d after implantation, but no significant difference was found at later stage. And the BIC showed difference at 7 and 28 d compared with pure HA. We concluded that Sr-HA coating can improve the bone osseointegration of the implant in the early stage compared with the HA coating.

Fluorescence microscopic analysis of bone osseointegration of strontium-substituted hydroxyapatite implants

The purpose of this study was to analyze the effect of strontium-substituted hydroxyapatite (Sr-HA) on bone osseointegration of the implants using fluorescence microscopy. We allocated 20 implants to two groups: Sr-HA group and HA group. Electrochemically deposited HA and Sr-HA coatings were applied onto the implants separately. All the implants were inserted into femur bone of rabbits. Oxytetracycline hydrochloride, alizarin-complexon, and calcein green were respectively administered 7, 28, and 46 d after the implantation. After eight weeks, femurs were retrieved and prepared for the fluorescence microscopy observation. We analyzed the bone mineral apposition rates (MARs), bone area ratios (BARs), and bone to implant contact (BIC) of the two groups. Fluorescence microscopic observation showed that all groups exhibited extensive early peri-implant bone formation. The MAR of the Sr-HA group was greater than that for pure HA from 7 to 28 d after implantation, but no significant difference was found at later stage. And the BIC showed difference at 7 and 28 d compared with pure HA. We concluded that Sr-HA coating can improve the bone osseointegration of the implant in the early stage compared with the HA coating.

多孔纯钛表面掺锶羟基磷灰石涂层对骨髓间充质干细胞粘附的影响(英文)

目的:观察电化学沉积的纳米结构掺锶羟基磷灰石涂层表面对大鼠骨髓间充质干细胞早期粘附行为的影响。创新点:首次观察电化学沉积的掺锶羟基磷灰石涂层表面骨髓间充质干细胞的早期粘附行为,并对相关基因进行了检测。方法:纯钛表面经过喷砂和双重酸处理,形成多孔粗糙结构。用电化学方法在其粗糙表面沉积羟基磷灰石涂层(HA)和掺锶羟基磷灰石涂层(Sr-HA)。用贴壁法将4周大鼠股骨骨髓间充质干细胞分离进行原代培养后将细胞接种到多孔纯钛,HA和Sr-HA表面培养1、6和24小时。用场发射扫描电镜(SEM)观察细胞的形貌特点。用异硫氰酸荧光素(FITC)标记的鬼笔环肽进行免疫荧光染色标记细胞骨架,Hoechst 33258进行细胞核染色,激光共聚焦荧光显微镜进行拍照后使用Image J进行细胞的计数和图形分析。用实时荧光定量逆转录聚合酶链式反应(RT-q PCR)测定24、48和72小时不同实验组中骨髓间充质干细胞中FAK、vinculin、integrin β1和integrin β3的基因表达,并进行统计学分析。结论:SEM观察结果显示,骨髓间充质干细胞在三种表面都能正常黏附、生长和增殖。在Sr-HA组表面,细胞粘附、细胞活力和细胞骨架的铺展都较粗糙表面组和HA组有较显著的提高。RT-q PCR结果显示,在各个时间点Sr-HA组表面骨髓间充质干细胞的FAK、vinculin、integrin β1和integrin β3的基因表达与粗糙组有显著性差异,且在24小时后与HA组亦有显著性差异。综上所述,掺锶羟基磷灰石纳米涂层具有较好的生物相容性,可以促进大鼠骨髓间充质干细胞在纯钛表面的早期粘附。