Preparation And Absorption Performance Studies Of Mesoporous Polydopamine Nano Core-shell Particles

Fe₃O₄@MPDA,Fe₃O₄@MPDA composite particles with pH response and HMPDA hollow mesoporous microcapsules were prepared respectively in this paper.In addition,the adsorption properties of these nanoparticles on dyes and drug molecules were also studied.The main research contents are as follows.1.Preparation and properties of Fe₃O₄@MPDA core-shell nanoparticlesSubmicron-sized magnetic Fe₃O₄ nanoparticles were prepared by solvothermal method.Triblock copolymers Pluronic F127 and 1,3,5-trimethylbenzene（TMB）were used as organic templates in the presence of Fe₃O₄ particles,and Tris was used as catalyst of dopamine polymerization.Ethanol and acetone were used as de-templated agents to synthesize magnetic mesoporous polydopamine core-shell nanoparticles.Morphology and chemical environment were characterization by Transmission electron microscope（TEM）,Scanning electron microscope（SEM）,X-ray diffractometer（XRD）,X-ray electron spectroscopy（XPS）,nitrogen adsorption-desorption and VSM.The adsorption properties of dye and drug molecules on carriers were also studied.The biocompatibility of the composites was evaluated by MTT method.The released DOX drug molecules still maintain pharmacological activity and significantly inhibition the growth of tumor cells.Finally,the DOX-Fe₃O₄@MPDA composite particles were surface-modified via electrostatic attraction with the chitosan/dialdehyde starch（CHI/DAS）multilayer polyelectrolyte,which makes the composite has excellent pH responsive property of drug sustained released.In the case of the tumor sites when pH is acidity,the drug is released quickly,which greatly improves the drug utilization rate.2.Preparation and adsorption property study of hollow mesoporous polydopamine（HMPDA）microcapsulesThe submicron SiO₂ particles were prepared by sol-gel method.First,SiO₂ particles were used as templates to obtain the core-shell SiO₂@MPDA nanoparticles.Then hollow mesoporous PDA microcapsules were prepared to remove the template SiO₂.The morphology and composition of the microcapsules were characterized by TEM,SEM,XRD,and XPS.The pore structure of the mesoporous materials was characterized by nitrogen adsorption desorption method and the maximum adsorption capacity of the MB was 1172.8 mg/g.Finally,the higher loaded and excellent sustained released performance of the microcapsules had been determined and the adsorption of DOX was 432.6 mg/g.In this paper,organic mesoporous core-shell composite particles were synthesized by organic-organic self-assembly method.The reaction conditions were mild,the raw materials were non-toxic and easily available,and PDA has high reactivity.It is easier to adsorb organic dyes or drug molecules than inorganic mesoporous materials.It has higher adsorption capacity,good biocompatibility and targeted delivery.The above properties are of great significance for its application in the field of biological medicine,especially the target drug carriers.