Recently, QDs have attracted enormous attention for their potential applications ranging from physics to medicine.
However, the toxicity of QDs impends its development in clinics experiment. In this work, we investigated the
reproduction toxicity of QDs for in vitro oocytes matureation. The immatured oocytes of 28 day Kunming mice were
harvested and cultured in vitro. And the biocompatible lysine-coated CdSe/CdS/ZnS QDs were incubated with oocytes
for a certain periods. Then, each single oocyte-cumulus-complex was visualized under Leica scanning confocal
microscope and rendered the 3-dimensional image. After 24 hrs, the maturation rate of oocytes decreased obviously
(from 62% to 21.8%) with the concentration of QDs increasing. The 3D rendered images of oocyte-cumulus-complex
showed that the most QDs distributed inside the cumulus, but no QDs entered oocytes. In summary, the results suggeste
that the oocytes maturation process has high susceptibility for disturbances of QDs. The more QDs were uptaken by
cumulus cells, the lower maturation rate of in vitro oocytes. We presume the QD interfere the process of oocytes
maturation by dysfunctioning the cumulus cells or disturb the signal-interaction between germ cell and somatic cell. To
our best knowledge, this is the first time that 3D visulization methods are used to analysize the reproduction toxicity of
in vitro oocytes. The further toxicity mechanism of QDs for oocytes in vitro is undergoing investigation.