Abstract: To explore the effect of cadmium telluride quantum dots (CdTe QDs) on the proliferation and osteogenesis differentiation of rat bone marrow mesenchymal stem cells (BMSCs),and to illustrate the toxicity of CdTe QDs in vitro,and to provide experimental evidence for application of CdTe QDs for living cell labeling marker.Methods Photoluminescence detector was used to detect photoluminescence emission spectra of the CdTe QDs in order to determine the dispersion of CdTe QDs in DMEM/F-12 medium.The rat BMSCs were cultured,and MTT assay was performed to examine the effects of different concerntrations (0,0.195 3,0.390 6,0.781 3,1.562 5,3.125 0,6.250 0,12.500 0,25.000 0,and 50.000 0 nmol·L^-1) of CdTe QDs on the proliferation of BMSCs;in vitro hexadecadrol,sodium glycerophosphate and vitamin C were used to induce osteogenesis differentiation. Alizarin red staining was used to display calcium nodus.The concentration inducing 50% of inhibition of proliferation (IP50) and the concentration inducing 50% of inhibition of differentiation (ID50) were calculated.Results Photoluminescence emission spectra showed that CdTe QDs were well dispersed in DMED-F/12 medium without segregation.The longer the exposure time went,the less the cell viability remained.The regression coefficients of 24,48 and 72　h exposure were separately －23.96,－29.61 and －24.30  (P<0.05);and the IP50 of each time was separately 7.25,1.63， and 0.67 nmol·L^-1.And the higher the exposure dose was,the lower the osteogenesis differentiation rate was.The regression coefficient of 48　h exposure was －56.15 (P<0.05),and the ID50 was 0.041 2 nmol·L^-1,and the ratio of IP50/ ID50 was 39.56.Conclusion At a certain concentration range (0.012 2－50.000　0 nmol·L^-1),CdTe QDs could inhibit the proliferation and osteogenesis differentiation of BMSCs.When CdTe QDs are used as living cell labeling marker,their influence in cell proliferation and differentiation should be considered.

Key words: cadmium telluride quantumdots, bone marrow mesenchymal stem cells, cell proliferation, cell differentiation