Laboratory for Bone and Implant Sciences, Division of Advanced Prosthodontics, Biomaterials, and Hospital Dentistry, The Jane and Jerry Weintraub Center for Reconstructive Biotechnology, UCLA School of Dentistry, Los Angeles, California 90095-1668, USA.
Tissue Eng Part A. 2009 Dec;15(12):3679-88. doi: 10.1089/ten.TEA.2008.0568.
The shelf life of titanium implant products, that is, a possible time-related change of their bioactivity, has rarely been addressed. The objective of this study was to examine the bioactivity of newly processed and aged titanium surfaces and determine whether ultraviolet (UV) light treatment of the titanium surface restores the possible adverse effects of titanium aging. Titanium disks, either acid-etched or sandblasted, were used immediately after processing (fresh surface) or after storing in dark for 4 weeks (aged surface). Some disks were treated with UV light for 48 h after 4 weeks of storage. Albumin adsorbed to the aged surfaces was only 15% of that adsorbed to the fresh surfaces during 2-h incubation, whereas UV-treated aged surfaces adsorbed equivalent amount of albumin to that for the fresh surfaces. During 24-h incubation, the number of human mesenchymal stem cells attached to the aged surfaces was less than half of that for the fresh surfaces, whereas UV treatment of the aged surfaces increased the number three times. Proliferation, alkaline phosphatase activity, and calcium deposition of the cells were substantially lower on the aged surfaces than on the fresh surfaces, while those on the UV-treated aged surfaces were higher than on the fresh surfaces. The strength of bone-implant integration evaluated at week 2 of healing in a rat femur model was reduced to half after 4 weeks of titanium aging, whereas UV treatment of the aged implants increased the strength to the level equivalent to or even higher than the freshly prepared implants. Fresh and UV-treated aged surfaces were superhydrophilic, while the aged surface was hydrophobic. The data suggest that bioactivity of titanium surfaces degrades with time and that UV treatment of the aged surface increases the bioactivity over the level of the freshly prepared surface.
钛植入产品的保质期，即其生物活性可能随时间变化的时间，很少被提及。本研究的目的是检验新处理和老化钛表面的生物活性，并确定钛表面的紫外线（UV）光处理是否能恢复钛老化的可能不良影响。酸蚀或喷砂处理后的钛盘在处理后立即使用（新鲜表面）或在黑暗中储存 4 周后使用（老化表面）。一些磁盘在储存 4 周后用 UV 光处理 48 小时。在 2 小时孵育期间，吸附在老化表面上的白蛋白仅为新鲜表面上的 15%，而经 UV 处理的老化表面吸附的白蛋白量与新鲜表面相同。在 24 小时孵育期间，附着在老化表面上的人间充质干细胞数量不到新鲜表面的一半，而 UV 处理的老化表面将数量增加了三倍。细胞的增殖、碱性磷酸酶活性和钙沉积在老化表面上明显低于新鲜表面，而在经 UV 处理的老化表面上则高于新鲜表面。在大鼠股骨模型中，愈合第 2 周评估的骨-植入物整合强度在钛老化 4 周后降至一半，而对老化植入物进行 UV 处理可将强度提高至与新制备植入物相当甚至更高的水平。新鲜和经 UV 处理的老化表面具有超亲水性，而老化表面具有疏水性。数据表明，钛表面的生物活性随时间降低，而老化表面的 UV 处理可提高生物活性，使其超过新制备表面的水平。
