Are Polymeric Microparticles Dangerous for Red Blood Cells?

Polymeric micro- and nanoplastic particles (MPs/NPs) have recently been recognized as potential biomedical pollutants that can enter the human bloodstream. Advances in analytical techniques have detected various polymers in human blood, raising concerns about their possible interactions with circulating cells, especially red blood cells (RBCs). RBCs are abundant, highly flexible, and lack internal repair mechanisms. This review summarizes current knowledge of how MPs and NPs interact with RBCs, emphasizing how physicochemical factors, including particle size, surface chemistry, environmental aging, and protein corona formation, influence hemocompatibility. Studies indicate that MPs can bind to RBC membranes, change the ζ-potential, reduce deformability, induce vesiculation and eryptosis, and, in some cases, cause hemolysis. These sublethal and lethal effects could have clinical significance, as even minor impairments in RBC mechanics may affect microvascular blood flow, oxygen delivery, and splenic clearance. Vulnerable populations—such as neonates and transfusion recipients—may be particularly susceptible to microparticle-induced RBC stress. While experimental data suggest MPs can harm RBCs, significant uncertainties remain regarding actual exposure levels, in vivo toxicity, and long-term health consequences. Addressing these gaps will require a multidisciplinary approach that combines environmental science, membrane biophysics, analytical chemistry, and clinical hematology to evaluate the health risks associated with increased microplastic exposure.