Zinc oxide spiky nanoparticles: A promising nanomaterial for killing tumor cells.

Zinc oxide (ZnO) nanostructures have been widely studied in biomedical fields due to their special properties. In recent years, ZnO spherical nanoparticles (SNPs) with nano-size as an anti-tumor agent have been widely concerned. While the effects of the non-spherical shaped ZnO nanoparticles on tumor cell death have been rarely reported. Here, we prepared ZnO spiky nanoparticles (SPNPs) as the research subject. We found that the SPNPs showed superiority in killing tumor cells. To be specific, SPNPs presented a long-term cytotoxicity effect on killing tumor cells, as plenty of SPNPs retained on the cell plasma membrane's exterior and still showed toxicity effect on tumor cells after co-incubation multiple times. Moreover, compared to SNPs, it was encouraging that SPNPs still showed stronger cytotoxicity in both simulated circulatory systems of tumor cells and 3D tumor cell spheroids. The stronger toxicity against tumor cells suggested that ZnO SPNPs have more advantages on killing tumor cells as a promising nanomedicine.