316L型含铜不锈钢与2种临床用输尿管支架表面结石形成对比研究

Comparative study on encrustation formation between 316L Cu-bearing stainless steel and two kinds of clinical ureteral stents

目的:探讨316L型含铜不锈钢与临床用输尿管支架表面结石形成情况以及抑制结石形成作用机制。方法:加工直径1.8 mm,壁厚0.1 mm,长度10 mm的316L型含铜不锈钢薄壁管材,与对照组临床用输尿管支架均浸泡于人工尿液中,每天换液,进行无机盐沉积实验。分别沉积1、2、3个月后,取出样品,采用扫描电镜、X射线光电子能谱对材料表面沉积盐进行分析。同时,采用电感耦合等离子体质谱仪测定316L型含铜不锈钢管材浸泡初期向人工尿液中溶出的铜离子量。此外,将不同样品分别与大肠杆菌和金黄色葡萄球菌悬液共培养,24 h后采用平板法测定材料杀菌率。结果:在不同浸泡时间,316L型含铜不锈钢表面沉积的结石量及结石尺寸均明显低于临床用输尿管支架材料;316L型含铜不锈钢每日铜离子溶出量为8.5μg/L,且其对大肠杆菌和金黄色葡萄球菌的杀菌率分别达到95.5%和91.0%。结论:316L型含铜不锈钢有望成为一种具有一定抑制结石形成功能的输尿管支架材料。

Objective:To investigate the crystal deposition on the surface of Cu-bearing stainless steel(316 L-Cu SS)and ureteral stents in clinic,respectively,and to further infer mechanism of inhibiting encrustation.Method:We prepared 316 L-Cu SS tubes with 1.8 mm in diameter,0.1 mm wall thickness and 10 mm in length.These tubes and ureteral stents,which were common in clinic,were all immersed in the artificial urine and changed daily.Crystal deposition tests were performed and SEM,XPS were used to analyze the composition.ICP-MS was used to measure the content of Cu ions released in initial period.Furthermore,the antibacterial rates against E.coli and S.aureus were examined with plating after being incubated for 24 h.Result:The immersion tests showed that less crystals were deposited on the surface of 316 L-Cu SS tube compared to the ureteral stents in clinic.Furthermore,the average content of copper ions released from 316 L-Cu SS was 8.5μg/L,and the anti-bacterial rates against E.coli and S.aureus were 95.5%and 91.0%,respectively.Conclusion:It was indicated that 316 L-Cu SS would be taken as a novel candidate ureteral stent material with the property of reducing encrustation formation.