Acute toxicity analysis of polyelectrolyte microcapsules with zinc oxide nanoparticles and microcapsule shell components using the aquatic organisms

Nanocomposite microcapsules with zinc oxide nanoparticles in their shells were fabricated using layer-by-layer assembly. An investigation of the toxic effect of microcapsules and their constituent components was performed for four types of test objects (ceriodaphnids (Ceriodaphnia affinis Lilljeborg), the Ekolyum biosensor (a culture of fluorescent genetically engineered Escherichia coli M-17 bacteria), midge larvae (Chironomus riparius Meigen), and aquarium fish (Brachydanio rerio)). It was established that, for each test object, the poly(allylamine hydrochloride) solution (PAH) used as a constituent component for the microcapsule shell formation has the maximal toxicity. The poly(sodium styrene sulfonate) solution (PSS) and a sample of microcapsules with a shell structure of (PAH/PSS)2(ZnO/PSS)3(PAH/PSS) have the least toxicity among the tested samples. At the same time, a significant decrease in the acute toxicity effect for the suspension of the microcapsules in comparison with their constituent components was detected. In the future, our results can be used in the development of a complex methodology for determining the toxicity parameters of a microcapsule, as well as the polyelectrolytes and inorganic nanoparticle colloids used as the initial material for the fabrication of nanocomposite microcontainers.