Eco- and bio-corona-based microplastics and nanoplastics complexes in the environment: Modulations in the toxicological behavior of plastic particles and factors affecting

Microplastics (MPs) and nanoplastics (NPs) have been discovered in diverse environmental milieux, and they have attracted much attention due to their possible toxicological impacts on living organisms. Likewise, salts, organic chemicals, heavy metals, natural organic matter, and other biomolecules are ubiquitously in the ecosystem. In a natural environment, MPs and NPs can interact with natural organic matter and biomolecules because of their exceptional characteristics. They can develop corona-based complexes, including eco-corona (EC) or bio-corona (BC) on the surface of MPs and NPs that not only change physiochemical characteristics but also its fate, distribution, uptake, transportation, biotransformation, and toxicological performance. Unlike orthodox toxins, coronas-based complexes on MPs and NPs rather than pristine MPs/NPs may be more hazardous. Therefore, the current critical review aims to discuss the up-to-date status of the modulations in the toxicological behavior of coronas-based MPs and NPs complexes on different environmental species. Significantly, it also focuses on the factors affecting the modulations of toxicological behavior of eco- and bio-corona-based MPs and NPs complexes for better understanding the role of environmental variables on the toxicity of plastics particles. Furthermore, this review systematically highlighted that the effect of a coronas-based complexes on the toxicological behavior of MPs and NPs is multifarious and variable in terms of plastic particle sizes, biomolecule's types, polymer types, environmental species, and designed experimental conditions. To sum up, the current review addresses existing knowledge gaps and suggests recommendations.