Kitsugi T, Nakamura T, Oka M, Yan W Q, Goto T, Shibuya T, Kokubo T, Miyaji S
Department of Orthopaedic Surgery, Faculty of Medicine, Kyoto University, Japan.
J Biomed Mater Res. 1996 Oct;32(2):149-56. doi: 10.1002/(SICI)1097-4636(199610)32:2<149::AID-JBM1>3.0.CO;2-T.
It has been proposed that the essential requirement for artificial materials to bond to living bone is the formation of bonelike apatite on their surfaces in the body. Recent studies have shown that titanium hydrogel and silica gel induce apatite formation on their surface in a simulated body fluid. In this study, the influence of titanium oxide and titanium silicate on the bonding of titanium alloys to bone was studied. Rectangular implants (15 x 10 x 2.2 mm) of titanium, Ti-6Al-4V, Ti-6Al-2Nb-Ta, Ti-6Al-4V coated with TiO2, and Ti-6Al-4V coated with Ti5Si3 were implanted into the tibial metaphyses of mature rabbits. At 8 and 24 weeks after implantation, the tibiae containing the implants were dissected out and subjected to a detaching testing. The failure load for titanium, Ti-6Al-4V, Ti-6Al-2Nb-Ta, Ti-6Al-4V coated with TiO2, and Ti-6Al-4V coated with Ti5Si3 were, respectively, 0.68 +/- 0.48, 0.22 +/- 0.46, 0.67 +/- 0.59, 2.18 +/- 0.71 and 2.03 +/- 0.41 kgf at 8 weeks, and 2.7 +/- 0.91, 2.58 +/- 1.29, 2.38 +/- 0.41, 3.79 +/- 1.7, and 2.79 +/- 0.87 kgf at 24 weeks after implantation. Histological examination by Giemsa surface staining, CMR, and SEM-EPMA revealed the coated titanium alloy implants directly bonded to bone tissue during early implantation. A Ca-P layer was observed at the interface of the coated implants and the bone. The results of this study indicated that TiO2 and Ti5Si3 can enhance the early bonding of titanium alloys to bone by inducing a Ca-P layer (chemical apatite) on the surface of titanium alloys. It also is suggested that the direct bone contact occurs in relation to the calcium and phosphorus adsorption onto the surface of the titanium passive layer formed during long-term implantation.
有人提出，人工材料与活骨结合的基本要求是在其体内表面形成类骨磷灰石。最近的研究表明，钛水凝胶和硅胶在模拟体液中可诱导其表面形成磷灰石。在本研究中，研究了氧化钛和硅酸钛对钛合金与骨结合的影响。将钛、Ti-6Al-4V、Ti-6Al-2Nb-Ta、涂有TiO2的Ti-6Al-4V以及涂有Ti5Si3的Ti-6Al-4V的矩形植入物（15×10×2.2mm）植入成年兔的胫骨干骺端。植入后8周和24周，取出含有植入物的胫骨并进行分离测试。钛、Ti-6Al-4V、Ti-6Al-2Nb-Ta、涂有TiO2的Ti-6Al-4V以及涂有Ti5Si3的Ti-6Al-4V在植入后8周时的失效载荷分别为0.68±0.48、0.22±0.46、0.67±0.59、2.18±0.71和2.03±0.41kgf，在植入后24周时分别为2.7±0.91、2.58±1.29、2.38±0.41、3.79±1.7和2.79±0.87kgf。通过吉姆萨表面染色、CMR和SEM-EPMA进行的组织学检查显示，涂层钛合金植入物在植入早期直接与骨组织结合。在涂层植入物与骨的界面处观察到一个Ca-P层。本研究结果表明，TiO2和Ti5Si3可通过在钛合金表面诱导形成Ca-P层（化学磷灰石）来增强钛合金与骨的早期结合。还表明，直接的骨接触与长期植入过程中形成的钛钝化层表面的钙和磷吸附有关。
