A different protein corona cloaks "true-to-life" nanoplastics with respect to synthetic polystyrene nanobeads

Understanding the impact of nanoplastics on the environment and living organisms is becoming increasingly urgent. Given the complexity of separating nanoplastics from environmental samples, to date fundamental studies are mostly conducted by using model synthetic nanobeads. Here we propose nanoparticles obtained by mechanical fragmentation under cryogenic conditions of daily-life polystyrene plastic items, "true-to-life" nanoplastics (T2LNPs), as a closer model to the real world. T2LNP samples are composed by populations of spheroidal nanoparticles with a broad multimodal size distribution, ranging from a few to hundreds of nanometers, in contrast with their synthetic counterpart, made of monomodal polystyrene spherical nanoparticles (165 nm). In addition, we show that upon incubation with human plasma a different protein corona forms on the T2LNPs with respect to the synthetic nanobeads. Since the protein corona is what the "cell first sees" when interacting with a nanoobject, this suggests that T2LNPs could be a more representative sample for studying the interaction of nanoplastics with biological systems and in turn for evaluating their effect on human health and the environment.