> Micro- and Nanoplastics Breach the Blood–Brain Barrier (BBB): Biomolecular Corona’s Role Revealed
> The blood–brain barrier (BBB) is an important biological barrier that protects the brain from harmful substances. In our study we performed short term uptake studies in mice with orally administered polystyrene micro-/nanoparticles (9.55 µm, 1.14 µm, 0.293 µm). We show that nanometer sized particles—but not bigger particles—reach the brain within only 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 coronae. 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 membrane of the BBB, whereas the protein model inhibited it.
So, in theory, a diet higher in protein and lower in cholesterol ought to be somewhat protective against nanoplastics crossing the blood brain barrier.
They found some brains have 1% of plastic in them by weight. 1% of the human brain by weight is 14g. A solid 14g plastic ball is 1.2 inches in diameter which is about the size of a golf ball.
You'd only be off by a factor of 3 instead of 4, then.
In any case, comparing it to a solid ball isn't so useful. Even the idea of "density" for something that is dispersed as small particles isn't too useful; proportion of mass is really the only useful metric.
This is not correct. A golf ball is closer to 1.7 inches in diameter, which is nearly three times the size of a 1.2 inch diameter ball in terms of volume.
How is it even getting to the brain- isn’t there a blood brain barrier that even pathogens have a hard time getting through?