Toxicity testing of four silver nanoparticle-coated dental castings in 3-D LO2 cell cultures

Abstract

To address the controversial issue of the toxicity of dental alloys and silver nanoparticles in medical applications, an in vivo-like LO2 3-D model was constructed within polyvinylidene fluoride hollow fiber materials to mimic the microenvironment of liver tissue. The use of microscopy methods and the measurement of liver-specific functions optimized the model for best cell performances and also proved the superiority of the 3-D LO2 model when compared with the traditional monolayer model. Toxicity tests were conducted using the newly constructed model, finding that four dental castings coated with silver nanoparticles were toxic to human hepatocytes after cell viability assays. In general, the toxicity of both the castings and the coated silver nanoparticles aggravated as time increased, yet the nanoparticles attenuated the general toxicity by preventing metal ion release, especially at high concentrations.

概要

目的

应用体外三维模型模拟肝脏组织微环境,更真实地反映和评估纳米银材料和牙科合金对于人体的潜在毒性。

创新点

借助中空纤维管和胶原蛋白首次构建了LO2 细胞三维聚集体,并将该模型应用到医用材料毒性的评价中。

方法

首先,采用扫描电镜观察中空纤维材料的孔径, 确保营养物质的正常交换。然后,将混合有胶原 蛋白的细胞悬液注入到中空纤维管的内胆,通过 尿素氮和白蛋白检测,确定最佳细胞密度进行长 期培养。在显微镜下观察细胞聚集体的形态,确 保模型的成功建立。其次,应用水热法制作纳米 银颗粒并将颗粒包裹到预先购买的合金材料上。 最后,用不同牙科材料的浸提液培养细胞1、3 和5 天,通过MTT 检测细胞死亡率,从而间接 评价材料的毒性。

结论

中空纤维材料的表征结果显示该材料具有较好的耐热性和细胞粘附性,孔径大小适宜营养物质交 换,可以应用到三维模型的构建中。通过白蛋白 和尿素氮两个指标来评价三维模型的活性,发现 每毫升5×104 细胞的浓度最适宜细胞生长(图4)。 进一步模型评价表明,相比于传统单层培养的细胞,三维模型中的细胞能保持长期活力(图6) 且可以在更短时间内对低药物浓度作出反应。