New research reveals that nominally identical microplastic model particles from different manufacturers differ in their properties. These particles interact differently with cells. This finding adds new insight to microplastic research since many studies rely on these model particles.
This research was carried out by team at the Collaborative Research Centre 1357 – Microplastics at the University of Bayreuth. The results were published in the journal Nature Communications.
Identical Particles Show Different Physicochemical Properties
Microplastics are everywhere in our environment. The oceans, rivers, soil, air – wherever researchers look for these, they usually find them. Due to their ubiquity, microplastics have been described as contaminants of emerging concern. They pose a risk to organisms, ecosystems, and to human health.
Numerous studies on the potential effects of microplastics for cells, organisms, and ecosystems have been published. Often, these studies use commercial spherical microparticles made from polystyrene as models. However, these studies often show contradictory results. Some of them showing adverse effects whereas others do not. This discrepancy makes it hard to assess the risks associated with microplastic particles.
Researchers discovered that identical polystyrene microplastic particles from different manufacturers differ in their physicochemical properties. These differences are an important factor for the interactions of the microplastic particles with cells.
One key factor identified was the particles’ zeta potential, related to their charge in a solution. Particles with a higher zeta potential interacted more strongly with cells. These particles were internalized more efficiently into the cells.
Explains Contradictory Results of Previous Studies
“The interactions of microplastic particles with cells are a basis for potentially hazardous effects on organisms,” stresses prof. Dr. Holger Kress, one of the initiators of the study. He continues, “These interactions may also determine how microplastic particles can cross biological barriers, infiltrate tissues, and distribute in the organism.”
The results of this study provide a possible explanation for the contradictory results of previous studies. They highlighted the strong differences between identical polystyrene particles from different manufacturers. With this the researchers show the necessity to thoroughly characterize the physicochemical properties of the microplastic model particles in effect studies.
Prof. Dr. Christian Laforsch, spokesperson of the CRC 1357 – “Microplastics” and one of the initiators of the study emphasizes, “Microplastics are not just microplastics. Our study underlines this complexity of the microplastic problem and highlights that physicochemical properties of microplastic particles are important to understand their interactions in the environment.”
The researchers want to raise awareness about this problem in the scientific community with this study. They emphasize the need for study comparability to ensure reliable assessments of microplastic risks and the development of eco-friendly plastics.