Nanoplastics found in the heart of chicken embryo raises health concerns

“We have injected plastic nanoparticles intravenously into the chicken embryo. This is the first time this approach has been used to study the biodistribution of plastic nanoparticles to multiple organs of the embryo,” the scientist said.

Nanoplastic behavior in chicken embryos

The study provides insights into the biodistribution of nanoplastics in embryos after they enter the embryonic bloodstream.

These nanoparticles are very small, even so small that they cannot be seen with a regular microscope. That’s why they are marked with fluorescent markers or europium. This enabled them to follow and further study the nanoparticles.  

They discovered that nanoparticles can cross the walls of blood vessels and accumulate at high levels in both the heart and liver. “Some nanoplastics are excreted through the kidneys,” said Wang.

As they pointed out in the study, nanoplastics were also found in a type of heart tissue that does not have blood vessels, known as avascular heart cushions.

According to Wang, they believe that nanoplastics could enter the heart through an opening. “These are small openings within the developing heart tissue that play a role in the formation and remodeling of the heart’s structure during development,” she added.

Why chicken and not human?

According to the study the chicken shares a high degree of genetic similarity with humans. For example, about 60 % of chicken protein-coding genes have at least one human orthologue. Orthologues are genes that evolved from a common ancestral gene, but they kept a similar function in different species.

This suggests that chicken embryos can imitate human tissues, as mammals cannot be used in such studies.

As scientists explained there are two reasons. First, the embryo is inside the mother’s uterus, surrounded by extraembryonic membranes. Meaning that the access is not possible. And the second is that for example, nanoplastic injected into the mother’s bloodstream could cross the placental barrier.

How they got the idea?

Nanoplastics are everywhere these days: in the ocean, soil, and even the food chain. Wang mentioned that they’ve even discovered nanoplastics in human placentas.

The question that was on her mind was what happens when those nanoplastics end up in the blood of the embryo?

“During an earlier study, we discovered that a high concentration of nanoplastics can cause malformations in the heart, eyes, and nervous systems of chicken embryos. But for a more complete understanding of the toxicity of nanoplastics, we first need more information about how they spread from the blood throughout the rest of the body,” she explained.

The importance of the study

As the scientists pointed out the results can improve the understanding of the interactions of nanoplastics with tissues inside living organism.

For example, those data can be useful in nanomedicine, and understanding the risks in terms of toxicity.  

“Now that we know how these nanoplastics are spreading, we can start looking into the health risks,” Wang concluded, adding, “There’s already research linking nanoparticles to a higher risk of heart attack and stroke. Especially during the development phase, nanoparticles could potentially be very dangerous.”

The study was published in Environment International.