Reproductive Toxicity And Mechanism Of Female Mice Exposure To Quantum Dots In Pregnancy

Objective:To observe the reproductive toxicity and mechanism of female mice exposure to Quantum Dots in pregnancy.Methods:Different treatment materials were administered by tail vein injection once a day for three consecutive days in early gestation?GD 2-GD 4?,middle gestation?GD7-GD 9?and late gestation?GD 15-GD 17?,respectively.Mice were sacrificed on the18th day of pregnancy and the methods of weighing measuring,pathological technology were used to assess the reproductive toxicity of CdSe/ZnS QDs.Compare the reproductive toxicity of"CdSe/ZnS QDs"and"CdCl2"on the uterus,placenta and fetal,to understand the mechanisms of CdSe/ZnS QDs toxicity?whether nanoparticles or metal ions?.The concentrations of cadmium in placenta and embryonic tissues were determined by inductively coupled plasma–mass spectrometry?ICP-MS?to understand the efficiency and mechanism of CdSe/ZnS QDs through placental barrier in vivo.Analyze of the body weight,blood routine,blood biochemical and histopathological changes of the offspring at PND 21?out of milk?and PND 60?sexual maturity?to assess the toxicity of CdSe/ZnS QDs on offspring.Assess the effects on gene specific expressions for apoptosis,oxidative stress,inflammatory reaction and nutrients'transportation to understand the mechanism of CdSe/ZnS QDs reproductive toxicityResults:1.The CdSe/ZnS QDs intravenously injected into pregnant mice could results in the damage of liver,uterus,placenta and embryo tissues but showed no sign of embryonic malformation.2.The CdSe/ZnS QDs intravenously injected into pregnant mice were accumulated in the maternal liver,uterus,and placenta tissues.The CdSe/ZnS QDs could not cross the placental barrier to embryonic tissues and exerted no obvious toxicity on the offspring after birth.3.The mRNA transcript levels of IFN-?were up-regulated at 2.23 fold at the placenta during the early gestation period that was exposed to the CdSe/ZnS QDs in the placenta.The GSH-Px,SOD,eNOS,GluT₁,IGF-2 and IL-10 were respectively down-regulated for 1.73,1.79,1.39 3.02,1.37 and 7.42 fold respectively compared with the control.Similarly,in the middle or late stages,there was significant up-regulation of IFN-?,down-regulation observed in the transcript levels of GSH-Px,SOD,eNOS,GluT₁,IGF-2 and IL-10 in the placenta compared with the control.A significant up-regulation of genes related to apoptosis?Bax,Caspase-3 and Caspase-9?in the placenta were also found in the early and middle gestation.Conclusion:1.CdSe/ZnS QDs have reproductive toxicity on pregnancy female mice and embryos.2.Reproductive toxicity of CdSe/ZnS QDs relates with the nanometer characteristics and metal particles.3.After pregnant mice exposed to CdSe/ZnS QDs,the CdSe/ZnS QDs are accumulated in the placenta and may be responsible for the observed placenta necrosis,vascular anomalies,increase the adverse effects on the embryo development without indications of transport into the embryonic tissues as well as the absence of toxicity in the offspring.