Study On Fabrica TiOn And Performance Evalua TiOn Of A Novel Quercetin-Loaded Nano Drug Carrier System Based On Mn-Doped SiO₂

objective: The manganese-containing silica carrier was prepared,loaded with quercetin and blocked with carboxymethyl chitosan,which could solve the drug restric TiOn of low solubility of quercetin,and make quercetin have ideal controlled-release performance.The thermodynamic and kinetic model of quercetin adsorp TiOn by manganese-containing silica nanoparticles was fitted,and the structure and release characteristics of the nano-drug loading system were studied.Methods: Manganese-containing silica carriers were synthesized using surfactant as a template by in situ doping method.By grafting silica was modified into which quercetin was encapsulated as a model drug.Langmuir,Freundlich and Temkin isothermal adsorp TiOn models were used to fit the thermodynamic data of quercetin adsorp TiOn on manganese-containing silica carriers.Quasi-first-order kinetics,quasi-second-order kinetics and intra-particle diffusion model were used to fit the adsorp TiOn kinetic data.Carboxymethyl chitosan was used to block quercetin in the pores to prepare the manganese-containing silica nano-drug carrier system.Powder X-ray diffrac TiOn,X-ray photoelectron spectroscopy,field emission scanning electron microscope,energy dispersive X-ray spectrum and transmission electron microscopy were used to characterize the sample.The in vitro release of nano-drug loading system was evaluated by dialysis bag method.Cytotoxicity and blood compatibility were also studied.Results: The nano-drug loading system of quercetin based on carboxymethyl chitosan was successfully prepared.The thermodynamic and kinetic adsorp TiOn of quercetin on manganese-containing silica carriers decreased in the order of 25 >35 >45.The best thermodynamic fitting model was Freundlich isothermal adsorp TiOn model,and the best kinetic fitting model was quasi-second-order kinetic model.Under the acidic condi TiOn of p H 6.5,Mn-doped silica could significantly improve the biodegradability of silica nano-carrier through the fracture of Mn-o bond,and carboxymethyl chitosan had good swelling performance,which made the nano-carrier system have good p H response release performance.In p H 6.5,the cumulative release of nano-drug loading system reached92.53% within 50 hours,which was higher than that at other p H values(5.5 and 7.4).The effect of this p H value on drug release was beneficial to the treatment of tumors in acidic environment.Nano-drug loading system could significantly improve the therapeutic effect of quercetin on MCF-7 cancer cells,and the hemolysis rate was below 5%.Conclusion: The adsorp TiOn of quercetin on manganese-containing silica carrier corresponded with Freundlich isothermal model and quasi-second-order kinetic model.The temperature had an effect on the adsorp TiOn of quercetin on the carrier,and the environmental p H value affected the release of quercetin in the nano-drug loading system.This made the drug beneficial to the treatment of tumors with acidic environment,which provided a certain theoretical basis and practical experience for the practical applica TiOn of nano-carrier drugs.