Institute of Polymer Science and Engineering, National Taiwan University, Taipei 10617, Taiwan.
ACS Appl Mater Interfaces. 2010 Jun;2(6):1608-13. doi: 10.1021/am1001162.
The concern about toxicity for nanosilicate platelets (NSP) derived from natural montmorillonite clay is addressed. The NSP nanoclay was isolated from polyamine-salt exfoliation of the layered silicate clay into randomized individual plates, possessing multiple ionic charges on the surface of silicate plates with an average geometric dimension of ca. 80 x 80 x 1 nm(3). The material had been previously shown to be effective for antimicrobial and tendency for adhering onto the biomaterial surface based on the direct observation by using scanning electron microscope. The material safety on genotoxic effect was investigated by using three different test systems: the Comet assay test on Chinese Hamster Ovary (CHO) cells in vitro, micronucleus (MN) assay in vivo and the Salmonella gene mutation assay on strain TA98, TA100, TA102, TA1535 and TA1537. The Comet assay showed no DNA damage after 24 h of incubation with NSP of 1000 microg/mL. The MN test indicated no significant micronucleus induction in the CHO cells at the concentrations tested. With all five strains of Salmonella typhimurium, none of mutations was found. Furthermore, cytotoxicity of the same material was assayed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) release, showing a low cytotoxicity on CHO cells below 1000 microg/mL after 12 h incubation period and a dose-dependent effect after 24 h incubation. For feeding to rats, the acute oral toxicity was shown a low lethal dose (LD(50)) or greater than 5700 mg/kg body weight for both male and female Sprague-Dawley rats. Overall, the study has demonstrated the safety of the NSP for potential uses in biomedical areas.
对来源于天然蒙脱石粘土的纳米硅酸钠片（NSP）的毒性问题表示关注。NSP 纳米粘土是通过层状硅酸盐粘土的多胺-盐解理作用分离出来的，其层状结构被随机解理为独立的薄片，在硅酸盐薄片的表面带有多个离子电荷，平均几何尺寸约为 80 x 80 x 1nm(3)。根据使用扫描电子显微镜的直接观察，该材料以前被证明在抗菌和倾向于粘附在生物材料表面方面是有效的。使用三种不同的测试系统研究了该材料的遗传毒性效应安全性：体外中国仓鼠卵巢（CHO）细胞彗星试验、体内微核（MN）试验和菌株 TA98、TA100、TA102、TA1535 和 TA1537 的沙门氏菌基因突变试验。彗星试验显示，在孵育 24 小时后，1000μg/mL 的 NSP 没有造成 DNA 损伤。MN 试验表明，在所测试的浓度下，CHO 细胞中没有明显的微核诱导。用 5 种鼠伤寒沙门氏菌菌株进行测试，均未发现突变。此外，还通过 3-（4,5-二甲基噻唑-2-基）-2,5-二苯基四氮唑溴盐（MTT）和乳酸脱氢酶（LDH）释放试验对相同材料的细胞毒性进行了检测，结果表明在 12 小时孵育期内，CHO 细胞的细胞毒性低于 1000μg/mL，24 小时孵育后呈剂量依赖性。在对大鼠进行的急性口服毒性试验中，两种性别的 Sprague-Dawley 大鼠的半数致死剂量（LD(50)）或大于 5700mg/kg 体重，均显示出较低的致死剂量。总的来说，该研究证明了 NSP 在生物医学领域的潜在用途的安全性。
