We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Mechanisms of ingested polystyrene micro-nanoplastics (MNPs) uptake and translocation in an in vitro tri-culture small intestinal epithelium
AI summary Read the abstract
Researchers used a sophisticated laboratory model of the human small intestine to study how micro- and nanoplastics cross the gut barrier after simulated digestion. They found that smaller nanoplastics were absorbed more efficiently than larger microplastics, and the particles used multiple cellular pathways to cross the intestinal lining. The study provides new evidence about the mechanisms by which ingested plastic particles could potentially reach the bloodstream.
Micro and nanoplastics (MNPs) are now ubiquitous contaminants of food and water. Many cellular and animal studies have shown that ingested MNPs can breach the intestinal barrier to reach the circulation. To date however, the cellular mechanisms involved in intestinal absorption of MNPs have not been investigated with physiologically relevant models, and thus remain unknown. We employed in vitro simulated digestion, a tri-culture small intestinal epithelium model, and a panel of inhibitors to assess the contributions of the possible mechanisms to absorption of 26 nm carboxylated polystyrene (PS26C) MNPs. Inhibition of ATP synthesis reduced translocation by only 35 %, suggesting uptake by both active endocytic pathways and passive diffusion. Translocation was also decreased by inhibition of dynamin and clathrin, suggesting involvement of clathrin mediated endocytosis (CME) and fast endophilin-mediated endocytosis (FEME). Inhibition of actin polymerization also significantly reduced translocation, suggesting involvement of macropinocytosis or phagocytosis. However, inhibition of the Na-H exchanger had no effect on translocation, thus ruling out macropinocytosis. Together these results suggest uptake by passive diffusion as well as by active phagocytosis, CME, and FEME pathways. Further studies are needed to assess uptake mechanisms for other environmentally relevant MNPs as a function of polymer, surface chemistry, and size.
More Papers Like This
Uptake and effects of orally ingested polystyrene microplastic particles in vitro and in vivo
AI summary Read the abstract
Researchers studied the uptake and effects of orally ingested polystyrene microplastic particles using human intestinal cell models and rodent experiments. They found that smaller microplastics were taken up by intestinal cells and could cross the gut barrier, though the majority passed through the digestive system. The study suggests that while most ingested microplastics are excreted, a fraction can be absorbed, warranting further investigation into long-term health effects.
Size-Dependent Internalization of Microplastics and Nanoplastics Using In Vitro Model of the Human Intestine—Contribution of Each Cell in the Tri-Culture Models
AI summary Read the abstract
Using a lab model of the human intestine, researchers showed that smaller plastic nanoparticles (50 nm) crossed the gut lining more easily than larger ones, with specialized immune-sensing cells playing a key role in uptake. The particles that got through could potentially enter the bloodstream. This study helps explain how the tiniest plastic particles in food and water might get inside the human body.
Complex intestinal and hepatic in vitro barrier models reveal information on uptake and impact of micro-, submicro- and nanoplastics
AI summary Read the abstract
Using laboratory models of human intestinal and liver barriers, researchers studied how plastic particles of different sizes cross from the gut into the body. Smaller nanoplastics (25 nm) were more readily taken up than larger microplastics, and the intestinal mucus layer provided some protection against particle absorption. The study also found signs of oxidative stress and changes in how liver cells process foreign substances after plastic exposure, providing insight into how ingested microplastics could affect human organs.
Biological effects of polystyrene micro- and nano-plastics on human intestinal organoid-derived epithelial tissue models without and with M cells.
AI summary Read the abstract
Researchers exposed human intestinal organoid-derived epithelial tissue models with and without M cells to polystyrene micro- and nano-plastics, finding that nano-plastics caused greater disruption of barrier integrity and uptake than micro-plastics, and that M cell-containing models showed enhanced particle translocation compared to standard epithelial models.
Exposure of Polystyrene Nano- and Microplastics in Increasingly Complex In Vitro Intestinal Cell Models
AI summary Read the abstract
Researchers tested polystyrene nano- and microplastics across increasingly realistic models of the human intestine and found that only the smallest particles (50 nm) could cross the intestinal barrier. A mucus layer -- like the one in real human guts -- significantly reduced particle crossing, which is reassuring but highlights the need for more research on long-term, real-world exposure levels.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.