Nano-Bio interactions of clay nanotubes with colon cancer cells

Abstract Natural halloysite clay nanotubes (halloysite nanotubes, HNTs) are potentially used in colon cancer therapy owing to their excellent physicochemical properties. However, the size-dependent interaction between HNTs and colon cancer cells is still an unresolved challenge. Herein, we analyzed the interfacial interactions between HNTs and colon cancer cells, and evaluated the size-dependent biological effects of HNTs250, HNTs400, and HNTs650 (250, 400 and 650 nm in length, respectively). The effects of size on the mechanism of cellular internalisation were investigated. The results showed that smaller HNTs exhibited increased cellular internalisation. Moreover, the cellular internalisation efficiency strongly depended on adsorptive endocytosis because smaller HNTs tended to accumulate near the cell membrane, facilitating internalisation, due to variations in surface charge. These findings indicated that cellular internalisation could be regulated by size and surface charge, providing the experimental evidence and rational design to enhance the efficacy for cancer therapy.