The study was to prepare composite calcium phosphate cement with improved repair and anti-tumor injectable sustained-release selenium nanoparticle. Na2SeO3/CS sustained release selenium nanospheres were prepared by emulsification and crosslinking method. The microspheres were combined with calcium phosphate cement (CPC) to prepare the Na2SeO3/CS/ CPC bone repair system. The curing time, mechanical strength, sustained release selenium and degradation properties, morphology and phase composition of the system were measured and characterized, and the activity of the cells in vitro was studied. The result showed that compared with pure CPC, when the amount of Na2SeO3/CS nano microspheres was 4 %,the injection of composite CPC was good, the curing time was 5.75 -11.5 minutes and the curing strength was improved. The microstructure showed that CPC was evenly wrapped on the surface of chitosan microspheres and formed a needle like HA crystal. The addition of the microspheres to the crystalline phase of the composite CPC material had no significant effect in the components. The sustained release selenium effect was good, the effective release was 22 d, and the degradation was better than the pure CPC. The honeycomb like three-dimensional porous structure of the network was formed, which was beneficial to the adhesion of tissue cells and blood vessels and nerves. In vitro cell test showed that the inhibitory effect of compound CPC on the proliferations of MCF-7 and MG-63 human osteosarcoma cells in human breast cancer cells was significant, and the inhibitory difference between the two cell proliferations was not significant. This study provided a new idea for non-bone bearing minimally invasive, defect repair and postoperative recovery of bone tumors, prevention and treatment of recurrence and metastasis, and provided an experimental basis for the rational application of functional element selenium.
