Recently, Huang Zhenlie, a professor from the School of Public Health of Southern Medical University, and his team revealed the possible neurotoxicity caused by the incomplete degradation of the most common biodegradable plastic polylactic acid microplastics particles in the intestinal tract of mice. Relevant research was published in Advanced Science on May 15.
"Although biodegradable plastics are considered as environmental alternatives to traditional plastics, their degradation process in the actual environment may pose unknown risks to human health." Huang Zhenlie, the corresponding author of the paper, said that the research results emphasized the importance of ensuring the complete degradation of polylactic acid microplastics particles in the digestive system of the body, To reduce their potential impact on human health.
This study analyzed the biotransformation, biodistribution and toxicity of polylactide polymer and polylactide oligomer microplastics in mice through repeated oral gavage for 28 days. The results showed that during the degradation of polylactide polymer and oligomer microplastics particles in the intestinal tract of mice, the partially degraded polylactide polymer microplastics particles would be transformed into oligomer nano plastic particles, thus increasing their bioavailability and toxicity, and intensifying the overall toxic effect related to polylactide microplastics particles. The polylactic acid oligomer micro plastic particles can be completely degraded in the intestinal tract, reducing their bioavailability, thereby reducing the toxicity.
In addition, this study found that the neurotoxic effect induced by polylactide polymer and polylactide oligomer microplastics has a common target and toxic mechanism, which mainly involves up regulating the expression of mitochondrial calcium uptake family member 3 (MICU3) in the midbrain region, leading to neuronal mitochondrial calcium overload. These findings not only provide new insights into the impact of biodegradable microplastics on human health, but also provide key information for assessing their risks and benefits compared with traditional plastics.
For this reason, Huang Zhenlie's team suggested that when designing biodegradable plastics for direct contact with human body, priority should be given to the use of low molecular weight materials on the premise of ensuring their functionality to ensure human health and safety.
In addition, Huang Zhenlie's team cooperated with Zhang Guoming, a professor of Shenzhen Eye Hospital, and found direct evidence of the existence of micro nano plastics in the closed internal environment of human eyeball vitreous body for the first time, and further analyzed the relationship between the discovered micro plastic spectrum and eye diseases. Relevant research was published in Science of The Total Environment on April 15.
Relevant paper information: https://doi.org/10.1002/advs.202401009
https://doi.org/10.1016/j.scitotenv.2024.171109
