Acute toxicity of zinc carbonate nanocrystals on white mice model

Zinc-based nanoparticles (NPs) are successfully used to meet the mineral needs of animals and poultry, capable of increasing the growth rate and the efficiency of their use of feed. Nanoparticles of zinc oxide are widely used, which are superior to conventional sources of zinc in terms of pharmacological activity and bioavailability, have a positive effect on productivity and antioxidant protection, and increase reproductive potential. However, a detailed investigation of their toxicological parameters showed the risks of their introduction into the body, as a result of which a large number of zinc oxide NPs were synthesized by the methods of “green chemistry”, the main drawback of which is a complex methodology and a high level of costs. We investigated the acute toxicity of a colloidal solution of zinc carbonate nanocrystals in a model of white mice. The experiment was conducted on 42 female non-linear white mice, 3–4 months old, with a live weight of 21–23 g, kept under optimal vivarium conditions. According to the principle of analogues, 6 experimental groups were formed: mice were injected with a colloidal solution of zinc carbonate nanoparticles in doses (by absolute weight of the drug) of 15,000.0; 20000.0; 25000.0; 30000; 35000.0 and 40000.0 mg/kg of body weight based on the absolute weight of the drug, which according to the active substance (zinc carbonate nanoparticles) was (37.5; 50.0; 62.5; 75.0; 87.5 and 100, 0 mg/kg of body weight), orally using an esophageal-gastric tube. Mice of the control group were injected with distilled water in a volume of 0.2 cm3 according to the same protocol. The clinical condition of the experimental animals was observed for 14 days, noting the appearance and development of clinical signs of poisoning, the time of death or recovery to the physiological norm. After the death (diagnostic slaughter) of the animals, a pathological autopsy was performed. Clinical observations showed that a single intragastric administration of the drug to mice of experimental groups 1-6 did not cause acute poisoning. The deaths of mice in all experimental groups were not observed during the 14-day observation period, as a result of which the LD50 indicator could not be calculated. At the same time, the maximum possible injected dose of the colloidal solution of zinc carbonate nanoparticles (by absolute weight) was 40,000.0 mg/kg of body weight (100.0 mg/kg by active substance), which allows the drug to be assigned to the VI class of toxicity – substances are relatively harmless (LD50 > 15000.0 mg/kg of body weight), and according to the degree of danger up to IV class – low-hazardous substances (LD50 > 5000.0 mg/kg of body weight).