The Study
Cellular internalization and release of polystyrene microplastics and nanoplastics.
This study watched tiny plastic beads in a dish with rat cells to see how they get inside and come out. It tells us what might happen at a cellular level, but it doesn't prove anything happens in people or animals eating plastic.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
Scientists tested tiny plastic balls (50 nm and 500 nm) to see how they get into and out of rat cells — like a door that only lets small things through.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 510 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1This means tiny plastic bits in the environment can sneak into your body’s cells more easily than bigger ones — and may be harder to get rid of.
- 250 nm particles entered and left cells more than 500 nm particles; 5 μm particles couldn't get in at all.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
The Science of the total environment
Year
2021
Authors
Ling Liu, Kexin Xu, Bowen Zhang, Yiyuan Ye, Qiu Zhang, Wei Jiang
Related Content
Claims (6)
Larger plastics break down into smaller particles called microplastics and nanoplastics through chemical reactions with oxygen, and these smaller particles can pass more easily through biological barriers like cell membranes.
Polystyrene particles of 50 nanometers and 500 nanometers enter rat basophilic leukemia cells through physical and cellular mechanisms, but 5-micrometer particles do not enter due to their larger size and reduced movement in solution.
When cells take in polystyrene particles of 50 nm or 500 nm in size, the particles end up mostly inside lysosomes, whether they enter through active uptake or passive entry.
When polystyrene nanoparticles enter rat cells, those that are 50 nanometers in size are released more efficiently than those that are 500 nanometers, through two known cellular mechanisms: passive movement across the cell membrane and active transport via lysosomes.
In rat cells, 50-nanometer polystyrene particles enter through clathrin-mediated and caveolin-mediated pathways, while 500-nanometer particles enter through macropinocytosis; the size of the particle determines which cellular uptake mechanism is used.
Polystyrene particles of 50 nm and 500 nm stick to artificial cell membranes due to physical forces, but they cannot enter the membranes unless cellular machinery is present to facilitate entry.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.