Summary: Two hours after ingestion, tiny particles of polystyrene, a plastic commonly used for food packaging, can be detected in the brain. These plastic particles can increase the risk of neuroinflammation and neurodegeneration.
Source: University of Vienna
The study was carried out on an animal model with oral administration of MNP, in this case polystyrene, a widely used plastic that is also found in food packaging.
Led by Lukas Kenner (Department of Pathology at MedUni Vienna and Department of Laboratory Animal Pathology at Vetmeduni) and Oldamur Hollóczki (Department of Physical Chemistry, University of Debrecen, Hungary), the research team was able to determine that tiny particles of polystyrene could be detected in the brain only two hours after ingestion.
The mechanism that allowed them to cross the blood-brain barrier was previously unknown to medical science.
“With the help of computer models, we discovered that a certain surface structure (biomolecular crown) was crucial for allowing plastic particles to pass through the brain,” explained Oldamur Hollóczki.
Health Impact Research
The blood-brain barrier is an important cellular barrier that prevents pathogens or toxins from reaching the brain. The intestine has a similar protective wall (intestinal barrier), which can also be penetrated by MNPs, as various scientific studies have demonstrated.
Intensive research is being conducted on the health effects of plastic particles in the body. MNPs in the gastrointestinal tract have previously been associated with local inflammatory and immune responses and the development of cancers.
“In the brain, plastic particles could increase the risk of inflammation, neurological disorders or even neurodegenerative diseases like Alzheimer’s or Parkinson’s,” said Lukas Kenner, stressing that more research is needed in this area.
Restrict the use of MNPs
Nanoplastics are defined as being less than 0.001 millimeters in size, while between 0.001 and 5 millimeters some microplastics are still visible to the naked eye. MNPs enter the food chain through various sources, including packaging waste.
But it’s not just solid foods that play a role, but also liquids: according to one study, anyone who drinks the recommended 1.5 to 2 liters of water per day from plastic bottles will end up ingesting around 90 000 plastic particles per year. .
However, drinking tap water instead can – depending on location – help bring that figure down to 40,000.
“To minimize the potential harm of micro- and nanoplastic particles to humans and the environment, it is crucial to limit exposure and restrict their use while further research is conducted into the effects of MNPs,” Lukas explained. Kenner.
The recently discovered mechanism by which MNPs cross protective barriers in the body has the potential to advance research in this area decisively.
About this neuroscience research news
Author: Karin Kirschbichler
Source: University of Vienna
Contact: Karin Kirschbichler – University of Vienna
Picture: Image is in public domain
Original research: Free access.
“Micro- and nanoplastics cross the blood-brain barrier (BBB): the role of the biomolecular corona revealed” by Lukas Kenner et al. Nanomaterials
Abstract
Micro- and nanoplastics cross the blood-brain barrier (BBB): the role of the biomolecular crown revealed
Humans are continually exposed to polymeric materials such as textiles, car tires, and packaging. Unfortunately, their breakdown products pollute our environment, leading to widespread contamination with micro- and nanoplastics (MNPs).
The blood-brain barrier (BBB) is an important biological barrier that protects the brain from harmful substances. In our study, we performed short-term absorption studies in mice with orally administered polystyrene micro-/nanoparticles (9.55 µm, 1.14 µm, 0.293 µm).
We show that nano-sized particles, but not larger particles, reach the brain within just 2 h after gavage. To understand the transport mechanism, we performed coarse-grained molecular dynamics simulations on the interaction of DOPC bilayers with a polystyrene nanoparticle in the presence and absence of various crowns.
We found that the composition of the biomolecular corona surrounding the plastic particles was critical for passage through the BBB.
Cholesterol molecules enhanced the uptake of these contaminants into the BBB membrane, whereas the protein template inhibited it. These opposite effects could explain the passive transport of particles in the brain.