Takeda S, Kosugi H, Takimoto T, Tsutsumi N, Nakamura M
Department of Biomaterials, Osaka Dental University.
Shika Zairyo Kikai. 1990 Nov;9(6):825-30.
Ag-Pd binary alloys with various palladium contents were extracted in Eagle's minimum essential medium by dynamic extraction at 200 rpm at 37 degrees C. The extracts were filtered through a 0.22 microns cellulose acetate filter, and the silver and palladium amount of the extracts and filtrates as dissolved metallic elements was measured with atomic absorption spectroscopy. Extracts and filtrates were also used in cultivation of L-929 cells to study in vitro cytotoxicity. An increase in the palladium content of the alloy resulted in decreased silver dissolution and increased palladium dissolution. The amount of palladium in the filtrates increased as the extraction period was extended, but the amount of silver was negligible in all filtrates. Extracts which had been extracted for 1 day showed strong cytotoxicity in pure Ag. However, the addition of palladium at a weight percent of more than 40% decreased cytotoxicity almost to the control level. Filtrate which had been extracted for 1 or 3 days was noncytotoxic in all alloys. However, the filtrate which had been extracted for 5 or 7 days showed cytotoxicity, which was especially strong in high-palladium alloys. These results demonstrate that extraction using a dynamic method appears to be useful in the investigation of their corrosion and biocompatibility.
将不同钯含量的银钯二元合金在37℃、200转/分钟的条件下于伊格尔氏最低必需培养基中进行动态萃取。萃取液通过0.22微米的醋酸纤维素滤膜过滤，然后用原子吸收光谱法测定萃取液和滤液中作为溶解金属元素的银和钯的含量。萃取液和滤液还用于培养L-929细胞以研究体外细胞毒性。合金中钯含量的增加导致银溶解减少，钯溶解增加。随着萃取时间延长，滤液中钯的含量增加，但所有滤液中银的含量均可忽略不计。萃取1天的萃取液在纯银中表现出很强的细胞毒性。然而，钯的重量百分比超过40%时，细胞毒性几乎降至对照水平。萃取1天或3天的滤液在所有合金中均无细胞毒性。然而，萃取5天或7天的滤液表现出细胞毒性，在高钯合金中尤为强烈。这些结果表明，采用动态方法进行萃取似乎有助于研究它们的腐蚀性和生物相容性。
