Desorption behavior of antibiotics by microplastics (tire wear particles) in simulated gastrointestinal fluids

Microplastics (MPs) are widely distributed throughout the environment. Upon ingesting MPs, the pollutants that they carry are then desorbed into organisms. This results in the accumulation of various chemicals within the organism. This study systematically examined the mechanism of antibiotic desorption using tire wear particles (TWP) as a carrier of antibiotics in simulated human gastrointestinal fluid and fish intestinal fluid. The findings of this study revealed the formation of cracks, pores, and depressions on the surface of photoaged TWP in an aquatic environment, as well as additional adsorption sites that are more favorable for the attachment of pollutants. Furthermore, the simulated human gastric fluid had a higher desorption rate than that of the fish intestinal fluid. The competition for TWP adsorption sites in the gastrointestinal fluid and the potential dissolution of antibiotics were the primary drivers of the increase in the desorption rate. The desorption rate in the simulated human gastrointestinal fluid was greater than that in the simulated fish intestinal fluid due to the composition of the gastrointestinal fluid. However, the carrying of pollutants by MPs poses a potential threat to human health. This study improves our understanding of TWP toxicity and has significant implications for the development of risk assessments.

Automated summary

Microplastics (MPs) are widely distributed and can carry pollutants into organisms, resulting in chemical accumulation. This study investigated the desorption mechanism of antibiotics carried by tire wear particles (TWP) in simulated human gastrointestinal fluid and fish intestinal fluid. The study found that photoaged TWP in an aquatic environment had cracks, pores, depressions, and additional adsorption sites for pollutants. The desorption rate was higher in simulated human gastric fluid than fish intestinal fluid due to competition for adsorption sites and potential dissolution of antibiotics. This study enhances our understanding of TWP toxicity and has implications for risk assessments.