Thanks to its flexibility, durability and affordability, plastic has entered almost every aspect of our lives. When these parts eventually degrade, the resulting micro and nanoplastics (MNPs) can harm wildlife, the environment and ourselves. MNPs have been found in the blood, lungs, and placenta, and we know they can enter our bodies through the food and fluids we consume.
A new study by a team of researchers from Austria, the USA, Hungary and the Netherlands has found that MNPs can reach the brain hours after eating, possibly because of the way other chemicals adhere to their surfaces. Not only is speed worrying, but the possibility of tiny polymers getting into our nervous system is seriously worrying.
“Plastic particles in the brain can increase the risk of inflammation, neurological disorders and even neurodegenerative diseases such as Alzheimer’s or Parkinson’s,” says pathologist Lucas Kenner of the Medical University of Vienna in Austria.
In the study, small pieces of MNPs given orally to mice could be detected in their brains in just two hours. But how do MNPs cross the blood-brain barrier that is supposed to keep the brain safe?
The blood-brain barrier, a system of blood vessels and tightly packed surface tissues, helps protect our brain from potential threats by blocking the passage of toxins and other unwanted substances while allowing more beneficial substances to pass through. It is quite clear that plastic particles are considered a material that reliably protects against delicate brain tissue.
“With the help of computer models, we found that a certain surface structure (biomolecular corona) is crucial for plastic particles to pass into the brain,” explains senior author Oldamur Hollocki, a nanoplastic chemist at the university. Debrecen in Hungary
To confirm that the particles could actually enter the brain, polystyrene MNPs (a common plastic used in food packaging) were labeled with fluorescent markers in three sizes (9.5, 1.14, and 0.293 micrometers) and pretreated with a digestive juice-like mixture. Used. fed mice.
“To our surprise, we detected specific nanometer-sized green fluorescent signals in the brain tissues of mice exposed to MNPs after just two hours,” the researchers wrote in their published paper.
“Particles as small as only 0.293 micrometers were able to absorb the gastrointestinal tract and cross the blood-brain barrier.”
How these tiny plastic shells cross cellular barriers in the body is complex and depends on factors such as particle size, charge, and cell type.
Smaller plastic particles have a higher surface area to volume ratio, making them more reactive and potentially more dangerous than larger microplastics. This reactivity is thought to allow small pieces of plastic to clump around other molecules and wrap them tightly with molecular forces, forming a strong cloak called a corona.
To study how particles can cross the most important neurological barrier, the researchers created a computer model of the blood-brain barrier, a double-lipid membrane made up of phospholipid found in the human body.
Four different plastic models were used to examine the role of the plastic particle crown. Modeling showed that particles with protein coronas could not enter the barrier. However, those with cholesterol corona can pass even if they cannot penetrate deeper into the brain tissue.
The results raise the possibility that plastic can be transported from the membrane to the brain tissue in a molecular cocktail. Knowing the basic mechanisms is an important first step in combating its harmful effects.
It is important to note that the results are based on mice and computer simulations, so it is unclear whether the same behavior has been observed in humans. It’s also unclear how many plastic particles are needed to cause the damage. However, according to the authors, knowing that coated plastic particles can cross the blood-brain barrier in such a short time contributes to the development of research in this area.
“To minimize the potential harm of micro and nanoplastic particles to humans and the environment, it is extremely important to limit exposure and limit their use as further research is conducted on the effects of MNPs,” says Kenner.
Source: Port Altele
