Targeted sonocatalytic cancer cell injury using avidin-conjugated titanium dioxide nanoparticles

在本研究中，我们将基于亲和素蛋白修饰的二氧化钛纳米颗粒(NPs)的声动力学疗法应用于癌细胞，这种纳米颗粒可以优先区分癌细胞和健康细胞。随后，在体外超声辐照(二氧化钛/超声处理)下活化后的二氧化钛纳米颗粒产生羟基自由基。虽然30%的正常乳腺细胞(人乳腺上皮细胞)显示出亲和素修饰的二氧化钛纳米颗粒的摄取，但超过80%的乳腺癌细胞(MCF-7)表现出亲和素修饰的二氧化钛纳米颗粒的摄取。然后，在1 MHz超声波(0.1W/cm~2，30 S)作用于含有纳米二氧化钛的细胞96h后，检测了二氧化钛/超声处理对MCF-7细胞生长的影响。至处理后24 h，未见明显的细胞损伤，但96 h时活细胞浓度下降至对照组的68%。

In this study, we applied sonodynamic therapy to cancer cells based on the delivery of titanium dioxide (TiO2) nanoparticles (NPs) modified with avidin protein, which preferentially discriminated cancerous cells from healthy cells. Subsequently, hydroxyl radicals were generated from the TiO2 NPs after activation by external ultrasound irradiation (TiO2/US treatment). Although 30% of the normal breast cells (human mammary epithelial cells) exhibited the uptake of avidin-modified TiO2 NPs, over 80% of the breast cancer cells (MCF-7) exhibited the uptake of avidin-TiO2 NPs. Next the effect of the TiO2/US treatment on MCF-7 cell growth was examined for up to 96 h after 1-MHz ultrasound was applied (0.1 W/cm2, 30 s) to cells that incorporated the TiO2 NPs. No apparent cell injury was observed until 24 h after the treatment, but the viable cell concentration declined to 68% compared with the control at 96 h.