We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Correlation between cellular uptake and cytotoxicity of polystyrene micro/nanoplastics in HeLa cells: A size-dependent matter
Summary
Researchers tested polystyrene particles of various sizes on human cells and found that only the smallest nanoplastics, those under about 25 nanometers in radius, could enter cells and cause toxic effects. Larger microplastic particles did not penetrate the cell membrane and showed no toxicity even at very high concentrations. The study provides a clear explanation for why smaller plastic particles tend to be more harmful, directly linking cell entry to cellular damage.
The cytotoxicity of micro/nanoplastics (MNPs) is known to be strongly influenced by particle size, but the mechanism is not clear so far. We reported the ability of polystyrene MNPs to be internalized by HeLa cells could be a reason for the size dependent cytotoxicity of MNPs. We found that small MNPs (10 nm and 15 nm in radius) could be efficiently internalized by HeLa cells, MNPs of 25 nm in radius could be slightly internalized by the cells, and larger MNPs could not enter the cells at all. We showed that only MNPs, which could be internalized by cells, had a toxic effect on cell activity in a dose-dependent manner. In contrast, MNPs, which could not be internalized by cells, showed no cytotoxicity even if at extremely high concentrations. We attributed the correlation between the size-dependent uptake of MNPs and the size-dependent cytotoxicity of MNPs to the enhanced reactive oxygen species (ROS) level and abnormal gene expression. Our study pointed out that cellular uptake is one of the most fundamental mechanisms for the cytotoxicity of MNPs.