Miao Peng, a doctoral researcher collaborating with the UGent Imptox team, explores the bioenergetic effects of simulated weathered nanoplastics on human intestinal cells.

Miao Peng, in collaboration with the Imptox team at Ghent University, delivered an intriguing talk at this year’s SETAC conference, exploring the potential health risks associated with nanoplastics in our environment. Their study focused on investigating how these tiny particles affect human intestinal cells, providing valuable insights into their potential impact on our well-being.

SETAC Conference: Addressing Environmental Challenges

The Society of Environmental Toxicology and Chemistry (SETAC) is a prestigious, not-for-profit organization comprising over 5,000 individuals and institutions across 90 countries. The annual SETAC conference is a global platform for professionals dedicated to studying, analyzing, and finding solutions to environmental problems, resource management, research and development, and environmental education. Under the motto "Data-Driven Environmental Decision-Making", this year's conference took place in Dublin from April 30th to May 4th. Given the increasing presence of micro- and nanoplastics (MNPs) in our environment, talks enquiring about the environmental and health impacts of MNPs have been ubiquitious on the agenda of this year’s conference.

The Prevalence of Nanoplastics in Our Lives

We know today that we are continuously exposed to microplastics (MP) and nanoplastics (NP) in our daily lives, raising concerns about their potential effects on our health. However, understanding the true impact of these particles is challenging. Many previous studies have examined the effects of high concentrations of pure nanopolymer particles on human cells, which may not accurately reflect the real-life exposure we experience as these particles undergo weathering in our environment.

Exploring the Impact on Cellular Energy

The Imptox team at Ghent University, led by Prof. Andreja Rajkovic, tackled this challenge by investigating the effects of simulated environmental NP samples on human intestinal cells. To mimic real-life conditions, they used a special approach. They transformed larger plastic pieces of PET (polyethylene terephthalate) into smaller ones of different shapes. These particles were then exposed to ultraviolet light for 1273 h, corresponding to 15 months of central European solar irradiance exposure, simulating the weathering process that NPs undergo in our environment. After this process, the researchers obtained tiny plastic particles called nano-PET. They exposed human intestinal cells to these nano-PET particles, along with nano-PS (polystyrene) particles, at levels similar to real-life exposure for 48 hours.

Key Findings on Health Impacts

The study's results provided important insights into the effects of simulated environmental NP on human health. They found that nano-PET particles had a stronger impact on cellular energy compared to nano-PS particles. Exposure to nano-PET stimulated various cellular energy processes in the intestinal cells, while nano-PS had different effects. The researchers also observed that the impact of UV weathering on nano-PET particles differed from that of the original particles. These findings highlight the need to consider the effects of both virgin and weathered NP on human health.

Full abstract of Miao Peng's presentation from the SETAC Abstract Book:

1.09.P-Mo056 Bioenergetic Status of Human Intestinal Caco-2 Cells After Exposure to Simulated Environmental Nanoplastic

Miao Peng1 , Maaike Vercauteren2 , Charlotte Grootaert3 , Ana I Catarino4 , Gert Everaert5 , Andreja Rajkovic3 , Colin Janssen6 and Jana Asselman7 , (1)Department of Animal Sciences and Aquatic Ecology, Ghent University (UGent), Ghent, Belgium, (2)GhEnToxLab, Ghent University (UGent), Ghent, Belgium, (3)Ghent University (UGent), Ghent, Belgium, (4)Flanders Marine Institute (VLIZ), Oostende, Belgium, (5)Ocean & Human health, Flanders Marine Institute (VLIZ), Oostende, Belgium, (6)Laboratory for Environmental Toxicology (GhEnToxLab), Ghent University (UGent), Ghent, Belgium, (7)Blue Growth Research Lab, Ghent University (UGent), Ghent, Belgium

The ubiquitous human exposure to nanoplastic (NP) in our daily life increasingly raises concerns regarding our health. Currently, it is difficult to evaluate effects of NP in real-life exposure as substantial studies exposed human cells to pure nanopolymer particles with rather high concentrations, which cannot represent complicated NP samples suffering weathering in our living environment. In this study, the bioenergetic effects of four simulated environmental NP samples on human intestinal Caco-2 cells were investigated. To this aim, big micro-PET (polyethylene terephthalate) particles were mechanically milled into a lower size range sample (M-PET) with multiple shapes. Then the M-PET particles and a polystyrene (PS) mixture (100 nm and 700 nm, mixed) were irradiated by ultraviolet (UV) light for 1273 h, corresponding to 15 months of central European solar irradiance exposure. After weathering procedures, both virgin and UV-weathered M-PET samples were filtered by 0.8-µm filter to obtain nano-PET particles with size less than 800 nm. Subsequently, Caco-2 cells were exposed to nano-PET and nano-PS samples with and without UV weathering at realistic exposure levels (101 -106 particles/mL) for 48 h. The mitochondrial respiration and glycolytic parameters of exposed cells were measured by Seahorse XF96 Analyzer. Based on these results, the harmful impacts of nano-PET on cellular bioenergy were stronger than those of nano-PS. Basal respiration, spare respiratory capacity, proton leak, and basal glycolysis were stimulated by stress from exposure to both virgin and UV-weathered nano-PET samples. Comparing virgin and UV-weathered nano-PET, the negative effects on mitochondrial respiration were alleviated while anaerobic glycolysis was enhanced for UV-weathered PET. Similarly, mitochondrial functions were more sensitive to virgin nano-PS while basal glycolysis was more vulnerable to UV-weathered PS sample. This research is the first to study bioenergetic responses of simulated environment NP samples on human health. It highlights that effects between virgin and weathered NP are different at a bioenergetic level, which has important implications for the risk assessment of NP on human health.