Huang Yi, He Jing, Gan Lu, Liu Xiaoguang, Wu Yao, Wu Fang, Gu Zhong-wei
National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, People's Republic of China. State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010, People's Republic of China.
Biomed Mater. 2014 Nov 10;9(6):065007. doi: 10.1088/1748-6041/9/6/065007.
The beneficial effect of a porous structure on the biological functions of calcium phosphate bulk ceramic or scaffold has been well documented. Nevertheless, the effect of a porous structure on the in vivo performance of hydroxyapatite (HA) coatings has been rarely reported, partly due to the difficulty in synthesizing porous HA coatings suitable for commercial applications. In this study, we have carried out a systematic in vivo study of porous HA-coated Ti implants (with and without surface modification) prepared by the liquid precursor plasma spraying process, in terms of its osteoconductivity and osteoinductivity. The results suggest the clear advantage of the porous structure over the dense structure, despite the pore structure (about 48% porosity and less than 100 μm average pore size) being far from the ideal pore structure reported for bulk ceramic. The porous HA-coated implant significantly promotes early bone ingrowth at the pre-generated defective region, and early fixation at the bone-implant interface, especially at early implantation time (one month), showing about 120% and 40% increases respectively over those of the dense HA-coated implants prepared by the conventional atmospheric plasma spraying process. Moreover, the porous structure can be readily used to incorporate collagen/rh-BMP2, which demonstrates clear ectopic bone formation. Overall, the results suggest the augmentation of bone ingrowth is significant for HA coatings with a porous structure, which is critical for the early fixation and long-term stability of medical implants.
多孔结构对磷酸钙块状陶瓷或支架生物功能的有益影响已有充分记载。然而，多孔结构对羟基磷灰石（HA）涂层体内性能的影响鲜有报道，部分原因是难以合成适用于商业应用的多孔HA涂层。在本研究中，我们对通过液体前驱体等离子喷涂工艺制备的多孔HA涂层钛植入物（有和没有表面改性）的骨传导性和骨诱导性进行了系统的体内研究。结果表明，尽管孔隙结构（孔隙率约为48%，平均孔径小于100μm）远非块状陶瓷报道的理想孔隙结构，但多孔结构相对于致密结构具有明显优势。多孔HA涂层植入物显著促进了预先形成的缺损区域的早期骨长入以及骨 - 植入物界面的早期固定，特别是在植入早期（一个月），分别比通过传统大气等离子喷涂工艺制备的致密HA涂层植入物增加了约120%和40%。此外，多孔结构可轻松用于掺入胶原蛋白/rh - BMP2，这显示出明显的异位骨形成。总体而言，结果表明具有多孔结构的HA涂层对骨长入的增强作用显著，这对医疗植入物的早期固定和长期稳定性至关重要。
