用于骨科和牙科应用的等离子喷涂羟基磷灰石涂层的相稳定性和生物学性能评估
Phase stability and biological property evaluation of plasma sprayed hydroxyapatite coatings for orthopedic and dental applications.
作者信息
Vahabzadeh Sahar, Roy Mangal, Bandyopadhyay Amit, Bose Susmita
机构信息
W.M. Keck Biomedical Materials Research Laboratory, School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164, USA.
W.M. Keck Biomedical Materials Research Laboratory, School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164, USA.
出版信息
Acta Biomater. 2015 Apr;17:47-55. doi: 10.1016/j.actbio.2015.01.022. Epub 2015 Jan 28.
In this work we have investigated the effects of strontium (Sr) dopant on in vitro protein release kinetics and in vivo osteogenic properties of plasma sprayed hydroxyapatite (HA) coatings, along with their dissolution behavior. Plasma sprayed HA coatings are widely used in load-bearing implants. Apart from osseointegration, the new generation of HA coating is expected to deliver biomolecules and/or drugs that can induce osteoinduction. This paper reports the preparation of crystalline and amorphous HA coatings on commercially pure titanium (Cp-Ti) using inductively coupled radio frequency (RF) plasma spray, and their stability at different solution pH. Coatings prepared at 110 mm working distance from the nozzle showed an average Ca ion release of 18 and 90 ppm in neutral and acidic environments, respectively. Decreasing the working distance to 90 mm resulted in the formation of a coating with less crystalline HA and phases with higher solubility products, and consequently higher dissolution over 32 days. A 92% release of a model protein bovine serum albumin (BSA) in phosphate buffer with pH of 7.4 was measured for Sr-doped HA (Sr-HA) coating, while only a 72% release could be measured for pure HA coating. Distortion of BSA during adsorption on coatings revealed a strong interaction between the protein and the coating, with an increase in α-helix content. Osteoid formation was found on Sr-HA implants as early as 7 weeks post implantation compared to HA coated and uncoated Ti implants. After 12 weeks post implantation, osteoid new bone was formed on HA implants; whereas, bone mineralization started on Sr-HA samples. While no osteoid was formed on bare Ti surfaces, bone was completely mineralized on HA and Sr-HA coatings after 16 weeks post implantation. Our results show that both phase stability and chemistry can have a significant influence toward in vitro and in vivo response of HA coatings on Ti implants.
在本研究中，我们研究了锶（Sr）掺杂剂对等离子喷涂羟基磷灰石（HA）涂层的体外蛋白质释放动力学、体内成骨特性及其溶解行为的影响。等离子喷涂HA涂层广泛应用于承重植入物。除骨整合外，新一代HA涂层有望递送可诱导骨诱导的生物分子和/或药物。本文报道了使用电感耦合射频（RF）等离子喷涂在商业纯钛（Cp-Ti）上制备结晶和非晶HA涂层，以及它们在不同溶液pH值下的稳定性。在距喷嘴110 mm工作距离处制备的涂层在中性和酸性环境中的平均钙离子释放量分别为18 ppm和90 ppm。将工作距离减小到90 mm导致形成结晶度较低的HA涂层和具有较高溶度积的相，因此在32天内溶解度更高。对于掺锶HA（Sr-HA）涂层，在pH为7.4的磷酸盐缓冲液中测得模型蛋白牛血清白蛋白（BSA）的释放率为92%，而纯HA涂层仅测得72%的释放率。BSA在涂层上吸附过程中的变形表明蛋白质与涂层之间存在强烈相互作用，α-螺旋含量增加。与HA涂层和未涂层的钛植入物相比，在植入后7周时，在Sr-HA植入物上就发现了类骨质形成。植入后12周，HA植入物上形成了类骨质新骨；而在Sr-HA样品上开始出现骨矿化。虽然在裸露的钛表面没有形成类骨质，但在植入后16周，HA和Sr-HA涂层上的骨完全矿化。我们的结果表明，相稳定性和化学性质都可对钛植入物上HA涂层的体外和体内反应产生重大影响。
Zotero 插件