Potential threats of nanoplastic accumulation in human induced pluripotent stem cells

[Display omitted] •hiPSCs were utilized to study human developmental toxicity of nanoplastics.•Excessive amounts of nanoplastics were internalized in hiPSCs within 48 h.•Nanoplastics reduced viable cells and their self-renewal capacity in a short time.•No serious toxicity was caused by nanoplastics in long-term differentiation tests. The threat to humans from nanoplastics (NPs) is increasing invisibly. Nowadays, many people are concerned about human safety and health, but few are reported about the effects of NP on humans. To overcome the limitations in human studies, human induced pluripotent stem cells (hiPSCs) were used as an optimal platform to investigate toxicity and subtle changes in differentiation caused by intracellular NPs accumulation for a long-term. Negatively charged polystyrene nanoplastics (PS NPs) were used to exclude acute toxic issues of surface charge and investigate the impact of the NP's size and nature during bioaccumulation. Intracellular observations revealed that excessive amounts of NPs were internalized into single cells and colonies within 48 h. Substantial growth inhibition and a slight reduction in self renewal capacity of hiPSCs occurred with respect to internalized NPs. Unexpectedly, the accumulated NPs in hiPSC did not exhibit chronic toxicity or adversely affect differentiation for 14 days.