Study On The Preparation Of GO And Fe₃O₄ Nano-composite Carriers And The Performance Of Controllable Drug Release Under Microwave Irradiation

The stimuli-responsive drug delivery systems(DDSs)have emerged as a highly functional therapeutic system for targeting tumors and are continuously improving.Because of its non-toxic and harmlessness,microwaves can be used to overcome drug resistance and attract people's attention.Graphene oxide(GO)exhibits strong absorbing properties mainly due to interfacial scattering,dielectric relaxation,multiple reflections,and resistive losses.Moreover,since there are a large number of delocalized electrons in GO,its dielectric relaxation process is also obvious.The modification of GO to the magnetic material can combine the dielectric loss and the electrical loss of GO with the magnetic loss of Fe3O4,so that the composite material has a better impedance matching,and then improves its microwave absorption performance.At the same time,the composite graphene quantum dots(GQDs)have unique fluorescence properties that can be used to monitor the drug delivery process.In addition,due to the rich oxygen-containing functional groups on the graphene surface,it is beneficial to increase the drug loading.Based on the above analysis,in this paper,the composites formed of multi-functional GO and Fe3O4 nanoparticles can improve the microwave thermal response,drug loading and fluorescence detection performance of GQDs.Three different structures of Fe3O4@GO,Fe3O4/nGO and(Fe3O4/nGO)@mSiO2/GQDs nanoparticles were prepared by GO,GQDs and Fe3O4,and the microwave thermal response performance and drug delivery and microwave drug release performance were studied.Firstly,Fe3O4@GO nanoparticles were synthesized by electrostatic interaction.The experimental results shown that the nanoparticles have obvious"core-shell" structure,good monodispersity,strong saturation magnetization(61.7emu/g)and microwave thermal conversion performance.DOX as the model drug,this nanocarrier has a loading rate of 98.2%and a microwave release rate of 71%.Then,Fe3O4/nGO multifunctional composite nanoparticles with hollow-mesoporous structure were prepared by one-step CTAB-assisted solvothermal method.The nanoparticles have a high saturation magnetization(76.02 emu/g)and a large surface area(57.35 m2/g),which is much larger than the surface area of Fe3O4 nanoparlicles(26.04 m2/g).It was found that the microwave thermal conversion performance of HMFG2-5 is the best;the drug loading of HMFG2-5 reaches 100%in only 40 minutes;and the microwave-controlled drug release rate is as high as 86.7%.Finally,the graphene quantum dots with fluorescence were further introduced to prepare(Fe3O4/nGO)mSiO2/GQDs nanoparticles.Its surface area increased to 359.8m2/g,the magnetic targeting was still good and the saturation magnetization value was 36.00 emu/g.Its drug loading rate for VP 16 was 68%and the drug release rate reaches 87%under microwave irradiation.It can be seen that a variety of applications of a material can be achieved by increasing the microwave thermal conversion performance and drug loading of the composite by graphene oxide and increasing the fluorescence detection performance of the drug carrier by the graphene quantum dots.