Generation of Eroded Nanoplastics from Domestic Wastes and Their Impact on Macrophage Cell Viability and Gene Expression

This study reports an innovative approach for producing nanoplastics (NP) from various types of domestic waste plastics without the use of chemicals. The plastic materials used included water bottles, styrofoam plates, milk bottles, centrifuge tubes, to-go food boxes, and plastic bags, comprising polyethylene terephthalate (PET), polystyrene (PS), polypropylene (PP), high-density polyethylene (HDPE), and Poly (Ethylene-co-Methacrylic Acid) (PEMA). The chemical composition of these plastics was confirmed using Raman and FTIR spectroscopy, and they were found to have irregular shapes. The resulting NP particles ranged from 50 to 400 nm in size and demonstrated relative stability when suspended in water. To assess their impact, the study investigated the effects of these NP particulates on cell viability and the expression of genes involved in inflammation and oxidative stress using a macrophage cell line. The findings revealed that all types of NP reduced cell viability in a concentration-dependent manner. Notably, PS, HDPE, and PP induced significant reductions in cell viability at lower concentrations, compared to PEMA and PET. Moreover, exposure to NP led to differential alterations in the expression of inflammatory genes in the macrophage cell line. Overall, this study presents a viable method for producing NP from waste materials that closely resemble real-world NP. Furthermore, the toxicity studies demonstrated distinct cellular responses based on the composition of the NP, shedding light on the potential environmental and health impacts of these particles.