Study Of PVA Magnetic Microspheres With Magnetic Ablation For The Treatment Of VX2 Liver Tumors

Objective:To prepare uniformly sized polyvinyl alcohol(PVA)magnetic microspheres and verify their feasibility for magnetic hyperthermia ablation in treating liver tumors.Methods:1.Preparation of PVA Magnetic Microspheres Containing Nano-Fe3O4 using the SPG membrane emulsification method.The morphology and particle size of the microspheres were observed using an inverted microscope and a scanning electron microscope.The PVA magnetic microspheres’ cross-linking reaction and elemental composition were analyzed using Fourier transform infrared spectroscopy(FTIR)and energy dispersive X-ray spectroscopy(EDS).2.The biocompatibility of the PVA magnetic microspheres was verified using the CCK-8 assay.3.Test the heating effect of PVA magnetic microspheres with different magnetic field strengths and verify the feasibility of in vitro treatment using Hep G2 cells through fluorescent staining.4.The feasibility of in vivo treatment using polyvinyl alcohol(PVA)magnetic microspheres was assessed in a rabbit ⅤⅫ liver tumor model.Therapeutic efficacy was evaluated two weeks post-treatment by comparing tumor size,weight,and pathological sections among the control group,embolization group,magnetothermal group,and microwave group.Results:1.The PVA magnetic microspheres prepared by the SPG membrane emulsification method exhibited uniform spherical shapes and regular morphology(49.15μm±1.42 μm).The FTIR spectrum showed that PVA was cross-linked with glutaraldehyde,forming a three-dimensional network structure with Fe3O4 nanoparticles encapsulated.The vibration peaks of the ether bond(-C-O-C)were observed at 1142 cm-1,1088 cm-1,and 844 cm-1.The EDS spectrum showed that the PVA magnetic microspheres contained C,O,and Fe,with Fe accounting for 26.5 wt%.2.The biocompatibility of the PVA magnetic microspheres was demonstrated by their non-toxic effect on L929 and Hep G2 cells after incubation with their extracts.3.Regarding magnetic heating performance,the average temperature of the PVA magnetic microspheres increased by 2.87℃.17.97℃.and 73.47℃ with the increase of magnetic field intensity at 0.6 kA/m.2.4 kA/m.and 4.8 kA/m.respectively.Magnetothermal therapy,investigated at the cellular level,demonstrated that a temperature of 54℃ can effectively induce apoptosis in tumor cells.4.In vivo magnetothermal ablation therapy experiments demonstrated that rabbit ⅤⅫ liver tumors,following embolization with polyvinyl alcohol(PVA)magnetic microspheres and exposure to an alternating magnetic field,could be heated to 62.9℃.Subsequently,the tumors turned grayish-white after being heated for 30 minutes.The long diameter and weight of the tumors in the control group and the embolization group were significantly larger than those in the magnetothermal group and the microwave group(p<0.05).However,no significant difference was observed between the magnetothermal group and the microwave group.Moreover,both the magnetothermal and microwave groups exhibited more thorough coagulative necrosis in pathological sections,suggesting that the therapeutic efficacy of magnetothermal ablation is comparable to that of microwave ablation.Conclusion:The SPG membrane emulsification method can successfully prepare PVA magnetic microspheres with uniform particle size,good biocompatibility,and effective heating properties.PVA magnetic microspheres have shown promising therapeutic efficacy in the magnetic hyperthermia treatment of rabbit ⅤⅩ2 liver tumors.providing an experimental and theoretical basis for magnetic hyperthermia treatment of liver cancer.