Reactive oxygen species drive aging-associated microplastic release in diverse infusion ingredients

Exposure routes and transport of microplastics (MPs) from the environment into the human bodies deserve considerable attention. Intravenous injection has been reported as a direct MP-intrusion pathway. However, it is unclear whether or how the infusion fluid composition influences polymer degradation and MP release. Here, we determined that the concentrations of MPs shed from infusion bags ranged from 522 to 5455 particles/L. The storage period, mechanical shaking, and storage temperature all contributed to MP release to some extent; however, the infusion fluid composition affected the formation of MPs more than any other factor. Infusion fluids containing moxifloxacin hydrochloride, etimicin sulfate, and sodium bicarbonate ringer's solution generated more reactive oxygen species than those containing sodium chloride, grape sugar, and glucose and sodium chloride. Specifically, the generation of reactive oxygen species (hydroxyl radicals, carbonate radicals, and single oxygen) facilitated oxygen-containing functional group formation and breaking of carbon chains on the surface of the polypropylene plastic, which increased aging and fragmentation. Overall, this study provides knowledge of the mechanisms underlying MP release from infusion bags during storage and transportation. This offers insight for optimizing the use and handling of infusion bags in medical settings to minimize contamination.