We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
The enhancement in toxic potency of oxidized functionalized polyethylene-microplastics in mice gut and Caco-2 cells
Summary
Researchers found that when polyethylene microplastics undergo oxidation in the environment, they become significantly more toxic to the gut than their unoxidized counterparts. In experiments with mice and human intestinal cells, oxidized microplastics caused more severe intestinal inflammation and disrupted the gut barrier. The study suggests that the environmental weathering of plastic waste may increase its biological harm, which is an important factor often overlooked in toxicity assessments.
Microplastics (MPs) are inevitably oxidized in the environment, however, to date, no studies have discussed the biological toxicity of oxidized polyethylene (Ox-PE) MPs. In this study, oxidized low-density polyethylene (Ox-LDPE), a representative Ox-PE, was prepared using a selective oxidation method. The difference in toxicity between LDPE-MPs and Ox-LDPE-MPs were evaluated in C57BL/6 mice and Caco-2 cells. The proton nuclear magnetic resonance (H NMR) and Fourier transform infrared (FTIR) spectroscopy analyses revealed that some hydrocarbon-containing groups were transformed into carboxyl and ketone groups during selective oxidation. In vivo experiment results showed that LDPE-MPs and Ox-LDPE-MPs exists in the intestinal (duodenum and colon) of mice, and Ox-LDPE-MPs caused more severe intestinal histological changes, oxidative stress, and inflammatory response. The gut microbiota data showed that the relative abundance of Lactobacillus decreased significantly in the LDPE-MP- and Ox-LDPE-MP-exposed groups (P < 0.05). The predicted Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathway suggested that exposure to LDPE-MPs or Ox-LDPE-MPs inhibited glycan biosynthesis and metabolism in the flora (P < 0.05). In vitro experiment results showed that selective oxidation to LDPE promoted its uptake by cells and aggravated adverse effects on cells, including reduced cell viability, damaged cell membrane, oxidative stress, and mitochondrial depolarization. The major mechanism of the increased toxicity of Ox-LDPE-MPs may be its easier accumulation and the ionic effect of oxygen-containing functional groups. Overall, these findings provide insights on the differences in toxicity between LDPE-MPs and Ox-LDPE-MPs. They also provide new perspectives for understanding the biohazards of MPs, which are necessary to accurately assess the potential environmental and health risks of these plastic pollutants.
Sign in to start a discussion.
More Papers Like This
Exacerbation of polyethylene microplastics in animal models of DSS-induced colitis through damage to intestinal epithelial cell conjunctions
Researchers tested the effects of UV-aged polyethylene microplastics on mice with chemically induced colitis, a model for inflammatory bowel disease. They found that the microplastics worsened intestinal inflammation by damaging the junctions between intestinal lining cells, weakening the gut barrier. The study suggests that microplastic exposure could aggravate existing gut conditions by compromising the protective intestinal wall.
Photo-transformation of microplastics and its toxicity to Caco-2 cells
Researchers studied how ultraviolet light transforms polystyrene microplastics and how these changes affect toxicity to human intestinal cells. They found that UV exposure roughened the particle surfaces and introduced oxygen-containing functional groups, and that these photo-transformed microplastics were significantly more toxic to Caco-2 cells than pristine particles. The study suggests that environmentally weathered microplastics may pose greater risks to the human digestive system than freshly produced ones.
Impact of Degradation of Polyethylene Particles on Their Cytotoxicity
Researchers found that degradation of polyethylene particles altered their cytotoxicity, with weathered and fragmented PE showing different toxic effects on cells compared to pristine particles, suggesting environmental aging changes microplastic health risks.
Comparative Analysis of Metabolic Dysfunctions Associated with Pristine and Aged Polyethylene Microplastic Exposure via the Liver-Gut Axis in Mice
Mice fed both new and weathered polyethylene microplastics developed disrupted fat metabolism, liver oxidative stress, and shifts in gut bacteria, with weathered (aged) particles causing more severe effects. This study suggests that the microplastics people encounter in the real world, which have been degraded by sunlight and time, may be more harmful than the pristine particles typically used in lab studies.
Polyethylene, whose surface has been modified by UV irradiation, induces cytotoxicity: A comparison with microplastics found in beaches
Researchers showed that polyethylene microplastics degraded by UV light, mimicking what happens to plastics in the environment, were toxic to immune and skin cells in lab tests. Fresh, undegraded plastic particles did not cause the same harm, meaning weathered microplastics found in nature are likely more dangerous than the pristine plastics typically used in lab studies. This suggests that real-world human exposure to environmentally aged microplastics may carry greater health risks than current research indicates.