Preparation And Research Of Hollow Mesoporous Silica Drug Carrier Based On CpG Functionalized Quantum Dots

The new tumor treatment model of chemotherapy combined with immunotherapy has become a research hotspot in the field of tumor treatment.In this paper,a multi-modal hollow mesoporous silica drug carrier was constructed based on quantum dots.It successfully loaded quantum dots,chemotherapeutic drugs and immune adjuvants,realized the monitoring and biological imaging of drug delivery.It effectively enhanced the anti-tumor effect through chemotherapy and immunotherapy.(1)CpG functionalized CdTe quantum dots were prepared by one-step synthesis method,and characterized by TEM,ultraviolet absorption spectroscopy and fluorescence spectroscopy,the results showed that the prepared quantum dots had good dispersion and excellent fluorescence performance;Hollow mesoporous silica(HMSS)nanoparticles were prepared by the self-template method,and the formation mechanism of the hollow mesoporous structure was studied through a series of characterization methods.The results showed that the prepared HMSS nanoparticles have good specific surface area and pore volume.The internal structure of the nanoparticles was complete and the dispersion was good;By using the amino groups on the surface of the HMSS nanoparticles and the carboxyl functional groups on the ss DNA chain,the CpG ODN immunoadjuvant was successfully loaded through the amide reaction;Using DNA hybrid strands as a blocking agent,the DNA-gated molecular structure was formed through the principle of base complementary pairing,and the mesoporous channels of DOX-loaded HMSS nanoparticles were blocked,and a multi-modal hollow mesoporous silica drug carrier was constructed.(2)By simulating the normal tissue environment of the human body and the external and internal environment of tumor cells,the drug release of nano-medicine carriers in the tumor microenvironment was analyzed.The results showed that under the condition of excessive mi RNA,with the decrease of p H,the drug release rate of the nano-drug carrier was continuously increasing;Under the condition of p H=5.0,with the increasing amount of mi RNA added,the drug release rate of the nano-drug carrier was increasing.Under the condition of p H=5.0,when excessive mi RNA was added at a certain moment,it was found that the drug release rate after adding mi RNA was significantly faster than that before adding mi RNA.The final result showed that the prepared nano-medicine carrier has a p H/mi RNA dual response drug release function.(3)Different concentrations of drug-loaded nanoparticles were prepared for in vitro cell experiments.The drug-loaded nanoparticles have almost no toxicity to normal human tissue cells,indicating that they have a certain degree of biocompatibility;It had strong cytotoxicity to He La cells,indicating that it has a good anti-tumor effect;The immunostimulatory activity experiment verified that the prepared drug-loaded nanoparticles have good immunostimulatory activity.The above in vitro cell experiment proved that the drug-loaded nanoparticles have better anti-tumor effects through chemotherapy combined with immunotherapy,which provided a new direction for chemotherapy and immunotherapy.