The Synthesis And Application Of Quantum Dots Based DNA Nano-hydrogel

Cancer is the leading cause of death worldwide.High-efficiency diagnosis and precise treatment of cancer have always been the problem that must to be solved by both researchers and medical workers.Nanocarriers which combined anticancer drugs with advanced nanoparticles can overcome the shortcomings of traditional chemotherapy and provide the efficient and precise treatments to cancer.Nano-hydrogels have attracted particular attention due to their excellent biological properties among those nanocarriers.In this paper,a novel nano-hydrogel carrier was constructed based on nucleic acid aptamers and quantum dots,and it was applied to cancer treatment.This research provides a new direction for the diagnosis and treatment of cancer,and the main contents are shown as follows:(1)The synthetic process of DNA functionalized CdTeSe alloy quantum dots with near-infrared emission was studied,including the effects of pH value,ratio of ligands,ratio of precursor,ssDNA and reaction time on its properties.Through the characterization of its fluorescence properties,chemical composition,fine structure and phase composition,the optimal process conditions for the preparation of DNA functionalized CdTeSe quantum dots were obtained.(2)Carboxymethylcellulose was used as the backbones,grafted with ssDNA on the surface of CdTeSe quantum dots,and then combined into nano-hydrogels by cross-linking agents of both miRNA-21 reverse sequence and cystamine through emulsification process.Based on the exploration of the optimal mixing ratio of surfactant,dosage of surfactant and cross-linking agent,a high drug-loaded quantum dot based DNA nano-hydrogel was prepared.The morphology,formation mechanism and drug-loading efficiency of nano-hydrogel were characterized.Moreover,the anti-tumor experiments showed that the nano-hydrogel has high drug-loading efficiency,drug-controlled release and good anti-tumor properties.The quantum dot-based DNA nano-hydrogel carriers prepared in this experiment would set a foundation for the construction of novel drug-loaded nano-hydrogel system.And this research would also provide the direction and power for anti-cancer treatment.