Okazaki Yoshimitsu, Gotoh Emiko
Institute of Mechanical Systems Engineering, National Institute of Advanced Industrial Science and Technology, Ecology-oriented Structural Material Group, 2-1 Namiki 1-chome, Tsukuba, Ibaraki 305-8564, Japan.
Biomaterials. 2005 Jan;26(1):11-21. doi: 10.1016/j.biomaterials.2004.02.005.
To investigate the metal release of each base and alloying elements in vitro, SUS316L stainless steel, Co-Cr-Mo casting alloy, commercially pure Ti grade 2, and Ti-6Al-4V, V-free Ti-6Al-7Nb and Ti-15Zr-4Nb-4Ta alloys were immersed in various solutions, namely, alpha-medium, PBS(-), calf serum, 0.9% NaCl, artificial saliva, 1.2 mass% L-cysteine, 1 mass% lactic acid and 0.01 mass% HCl for 7d. The difference in the quantity of Co released from the Co-Cr-Mo casting alloy was relatively small in all the solutions. The quantities of Ti released into alpha-medium, PBS(-), calf serum, 0.9% NaCl and artificial saliva were much lower than those released into 1.2% L-cysteine, 1% lactic acid and 0.01% HCl. The quantity of Fe released from SUS316L stainless steel decreased linearly with increasing pH. On the other hand, the quantity of Ti released from Ti materials increased with decreasing pH, and it markedly attenuated at pHs of approximately 4 and higher. The quantity of Ni released from stainless steel gradually decreased with increasing pH. The quantities of Al released from the Ti-6Al-4V and Ti-6Al-7Nb alloys gradually decreased with increasing pH. A small V release was observed in calf serum, PBS(-), artificial saliva, 1% lactic acid, 1.2% l-cysteine and 0.01% HCl. The quantity of Ti released from the Ti-15Zr-4Nb-4Ta alloy was smaller than those released from the Ti-6Al-4V and Ti-6Al-7Nb alloys in all the solutions. In particular, it was approximately 30% or smaller in 1% lactic acid, 1.2% L-cysteine and 0.01% HCl. The quantity of (Zr + Nb + Ta) released was also considerably lower than that of (Al + Nb) or (Al + V) released. Therefore, the Ti-15Zr-4Nb-4Ta alloy with its low metal release in vitro is considered advantageous for long-term implants.
为了在体外研究每种基体和合金元素的金属释放情况,将SUS316L不锈钢、钴铬钼铸造合金、商业纯钛2级以及钛6铝4钒、无钒钛6铝7铌和钛15锆4铌4钽合金浸泡在各种溶液中,即α-培养基、无磷酸盐缓冲盐水(PBS(-))、小牛血清、0.9%氯化钠、人工唾液、1.2质量%的L-半胱氨酸、1质量%的乳酸和0.01质量%的盐酸中7天。在所有溶液中,钴铬钼铸造合金释放的钴量差异相对较小。释放到α-培养基、PBS(-)、小牛血清、0.9%氯化钠和人工唾液中的钛量远低于释放到1.2% L-半胱氨酸、1%乳酸和0.01%盐酸中的钛量。SUS316L不锈钢释放的铁量随pH值升高呈线性下降。另一方面,钛材料释放的钛量随pH值降低而增加,并且在pH值约为4及更高时明显减弱。不锈钢释放的镍量随pH值升高逐渐降低。钛6铝4钒和钛6铝7铌合金释放的铝量随pH值升高逐渐降低。在小牛血清、PBS(-)、人工唾液、1%乳酸、1.2% L-半胱氨酸和0.01%盐酸中观察到少量钒释放。在所有溶液中,钛15锆4铌4钽合金释放的钛量均小于钛6铝4钒和钛6铝7铌合金释放的钛量。特别是在1%乳酸、1.2% L-半胱氨酸和0.01%盐酸中,其释放量约低30%或更低。释放的(锆+铌+钽)量也远低于释放的(铝+铌)或(铝+钒)量。因此,体外金属释放量低的钛15锆4铌4钽合金被认为对长期植入物具有优势。