pH响应性羧甲基化纤维素微球原位生长UiO-66及用于双氯芬酸钠的控释OA

Carboxymethylated cellulose microspheres(CMC-M)were first synthesized via etherification of cellulose microspheres(CM)with sodium chloroacetate.Subsequently,zirconium-based metal-organic framework UiO-66 was grown in situ onto the CMC-M biopolymer backbone to successfully fabricate UiO-66@CMC-M composite microspheres.The drug loading and controlled release performance of the composite were then evaluated using diclofenac sodium(DCF)as a model drug.Characterization results from scanning electron microscopy,energy-dispersive X-ray spectroscopy,Fourier-transform infrared spectroscopy,X-ray diffraction,and thermogravimetric analysis confirmed the successful integration of UiO-66 crystals on the CMC-M framework,suggesting potential coordination bonding between the carboxyl groups on CMC-M and the Zr4+nodes of UiO-66.Drug loading experiments indicated that DCF loading was governed by a combination of physical and chemical interactions,leading to monolayer adsorption.In vitro release studies demonstrated pH-responsive controlled release behavior of DCF@UiO-66@CMC-M.Under simulated gastric fluid(pH=1.2),the cumulative release of DCF was approximately 24%over 70 h,whereas it reached approximately 80%under simulated intestinal fluid(pH=7.4).Kinetic fitting revealed that the drug release profile followed the Korsmeyer-Peppas model,with the mechanism consistent with Fickian diffusion.Cytotoxicity assays further confirmed that UiO-66@CMC-M possesses excellent biocompatibility and negligible cytotoxicity.This study provides a theoretical foundation for the design of novel controlled-release carriers for DCF.