316L-Cu抗菌不锈钢种植体中Cu离子的抗菌活性

摘要

BACKGROUND:316L-Cu antibacterial stainless steel is made by adding a certain amount of copper into the stainless steel fol owed by a special heat treatment to uniformly disperse copper-rich precipitates in stainless steel substrate, thereby harvesting the antibacterial properties. OBJECTIVE:To evaluate the antibacterial activity of the Cu ions released from 316L type Cu-bearing antibacterial stainless steels against Porphyromonas gingivalis, thereby providing biomedical evidence for its clinical application. METHODS:The medical 316L stainless steel samples at a surface area to volume ratio of 0.1 cm2/L were soaked in simulated body fluids at 37 ℃ for 1-10 days. A graphite furnace atomic absorption spectrophotometer was employed to detect the amount of Cu release in the simulated body fluids each day and then the rate of Cu release per day could be determined. The antibacterial activities of the steel samples were evaluated by a standard film-covered method under a scanning electron microscope. RESULTS AND CONCLUSION:The daily Cu releasing amount from the 316L-Cu stainless steel within 10 days was significantly higher than that of 316L stainless steel, and al the values remained nearly constant. With time, the sterilizing rate of 316L-Cu stainless steel was gradual y increased, and reached 100%until the 10th hour. Porphyromonas gingivalis showed some morphological changes at 3 hours after treated with 316L-Cu stainless steel, appeared with cleavage at 6 hours, and mostly disintegrated into pieces at 9 hours. The results indicated that the 316L-Cu antibacterial stainless steel showed excel ent antibacterial property against Porphyromonas gingivalis, slowly release Cu irons, and alter the surrounding microenvironment, which is a highly promising biomaterial and has good clinical value.%背景：316L-Cu 抗菌不锈钢是通过在不锈钢中添加一定量的铜元素，并采取特殊的热处理使不锈钢基体中均匀弥散分布富铜析出相，从而赋予抗菌不锈钢优异的抗菌性能。目的：评价新型316L-Cu 抗菌不锈钢种植体对牙龈卟啉单胞菌的抗菌性能，并检测316L-Cu 抗菌不锈钢的Cu离子溶出行为，为其进一步临床应用提供生物医学证据。方法：以医用316L 不锈钢为成分基础，添加3.5%-4.0%的 Cu 元素制成316L-Cu 抗菌不锈钢。将其按0.1 cm2/L表面积对容量比置于模拟体液中，在37℃震荡水浴中浸泡1-10 d。采用石墨炉原子吸光光度计每天测定浸提液中的铜离子含量。通过覆膜法抗菌实验及扫描电镜形态学观察评价316L-Cu抗菌不锈钢的杀菌性能。结果与结论：316L-Cu抗菌不锈钢在模拟体液中浸泡1-10 d后的Cu离子溶出量远高于普通医用316 L不锈钢。随着作用时间的延长，316L-Cu抗菌不锈钢的杀菌率逐步提高，10 h时杀菌率已达100%。316L-Cu抗菌不锈钢作用3 h后牙龈卟啉单胞菌的菌体形态即出现明显的变化，6 h后菌体出现明显的裂解，9 h后材料表面绝大多数细菌即崩解为碎片。说明316L-Cu抗菌不锈钢能够有效地杀灭种植体周围炎的主要致病菌，同时能够缓慢释放Cu离子，改变种植体周围微环境，说明其为一种极具潜力的生物材料，具有良好的临床应用价值。