The Research In Molecular Mechanism Of The Apoptosis In Hela Cells Induced By Quantum Dots

Objective:1. Characterize the physical and optical properties of CdSe/ZnS QDs.2.To demonstrate the cytotoxic effects of CdSe/ZnS QDs by comparing theapoptosis ratios of CdSe/ZnS QDs and CdCl2treated Hela cells.3.Compare the amount of ROS in control group, CdSe/ZnS QDs groups andCdCl2groups, and analysis the apoptosis mechanism of Hela cells induced byCdSe/ZnS QDs.4. Find out the apoptosis mechanism of CdSe/ZnS QDs by detecting apoptosisrelated proteins in control group, CdSe/ZnS QDs groups and CdCl2groups.Methods:Firstly, characterize the physical features of CdSe/ZnS QDs by TEM, UVspectrophotometer and fluorescence spectrometer. TEM was utilized to detect the size,shape and the uniformity of apperance of CdSe/ZnS QDs, UV spectrophotometer wasutilized to measure the absorption wavelength range, and fluorescence spectrometerwas utilized to measure the emission wavelength range. Secondly, subculture Helacells and incubate Hela cells with different concentrations of CdSe/ZnS QDs andCdCl2for24h and48h, then test cell viability by MTT kit. Thirdly, test the apoptosisratio of Hela cells incubated with different concentrations of CdSe/ZnS QDs andCdCl2for24h by flow cytometry. Fourthly, detect the amounts of ROS generated inHela cells which were incubated with different concentrations of CdSe/ZnS QDs andCdCl2for24h by CDFH-DA kit. At the last, compare the expression of Bcl-2andBax in Hela cells incubated with different concentrations of CdSe/ZnS QDs andCdCl2for24h through western blot.Results:1. The optical properties of CdSe/ZnS QDs we used are excellent.2. CdSe/ZnS QDs are more cytotoxic than CdCl2and the cytotoxicity effects ofCdSe/ZnS QDs are depend on the concentration and the length of reaction time.3. CdSe/ZnS QDs treated Hela cells could induce more ROS than CdCl2, and the amount of ROS isdepend on the ceoncentration of CdSe/ZnS QDs.4. The apoptosis ratios of CdSe/ZnS QDs treated Hela are higher than CdCl2treated Hela cells, and the apoptosis ratio relates to the concentration of CdSe/ZnSQDs in cell medium.5. The expression of Bcl-2in CdSe/ZnS QDs treated Hela are less than CdCl2treated Hela cells, and the expression of Bax is in contrast.Conclusion:1. CdSe/ZnS QDs are small in diameter and good in optical tests.2.CdSe/ZnS QDs are cytotoxic and the cytotoxicity of CdSe/ZnS QDs arestronger than CdCl2, and the cytotoxic effects of CdSe/ZnS QDs are depend on theconcentration.3. The apoptosis pathway induced by CdSe/ZnS QD relates to the generation ofROS, the over expression of Bax, and the less expression of Bcl-2.