Plastics are synthetic polymers derived from fossil fuels or biomass, which is a renewable organic material that comes from plants and animals of different origins. The use of plastic products has grown exponentially because of their superior qualities, including their high durability, waterproof nature, chemical stability, and low cost and ease of manufacturing. The increase in the production and use of plastic products has resulted in a substantial amount of plastic waste, which is accumulating in every environmental compartment.
In their life cycle, plastics can fragment into micro and nanoplastics (MNPs). In recent years, MNPs have become a growing concern to human health due to our constant contact with polymeric materials, for example, textiles, food packaging, and car tyres. It is presumed that food consumption is the main route of human exposure to MNPs, though inhalation is also a possibility due to the substantial amount of MNPs in the environment and their small size. MNPs have been found in various human organs, including the gastrointestinal tracts, lungs, placenta, and blood, proving their capacity to translocate from their point of entry to other parts of the body. Studies have found that MNPs are even able to penetrate cells that make up crucial biological barriers such as the intestinal mucosal barrier. Animal exposure studies have also found MNPs entering other crucial organs including the brain, suggesting that the blood-brain barrier, which protects the brain from harmful substances, was penetrated. The process whereby MNPs cross these barriers is a complex process that depends on several factors such as particle size, chemical charge, surface chemistry, and the type of cell with which they interact. This study aims to use human cell cultures to study the behaviour and fate of MNPs in contact with and across the blood-brain barrier, to expand our understanding of the health risks of MNPs.
