Study On The Effect And Mechanism Of Iron Oxide Nanoparticles Loaded With Paclitaxel Inhibits Glioblastoma

Objective: To prepare and identify iron oxide nanoparticles loaded with paclitaxel(IONP@PTX)and to explore the inhibitory effect of on Glioblastoma(GBM)and its potential mechanism.Methods: IONP@PTX was synthesized by high-temperature pyrolysis and phase transfer method,characterized cumulative release rate and drug loading by UV spectrophotometer and high-performance liquid chromatography,and then characterized using particle size analysis,zeta potential and transmission electron microscope(TEM).HMC3 cells and U251 cells were separately incubated with IONP@PTX and PTX,and then cell viability was detected by Cell Counting Kit-8 to determine the toxic of PTX and IONP@PTX.U251 cells were separately incubated with PTX,IONP@PTX,combination of IONP@PTX with 3-MA and combination of IONP@PTX with rapamycin,and then cell viability was detected by Cell Counting Kit-8.Cell migration and invasive capability was assessed by Scratch wound healing and Transwell migration and invasion assays.Intracellular reactive oxygen species(ROS)and lipid peroxidation were determined using 2′-7′-dichlorodihydrofluorescein diacetate and C11-BODIPY staining,respectively.Intracellular concentration of iron ions was quantified spectrophotometrically.Expressions of autophagy and ferroptosis biomarkers were detected by western blot assay.U251 cells were subcutaneously injected into the right forelimb of mice to establish GBM xenografts.When the tumor can be seen by the naked eye,the mice were given intraperitoneally with saline,IONP@PTX,combination of IONP@PTX with3-MA and combination of IONP@PTX with rapamycin,respectively.Then,inhibitory effect of IONP@PTX on GBM was evaluated by measuring tumor growth and body weight,separation of tumor tissue by surgical for assessing the expression level of GPX4 protein.At the same time,mice without tumor were injected intraperitoneally with normal saline,IONP@PTX,IONP@PTX combined with 3-MA or IONP@PTX combined with rapamycin.Moreover,the toxicity of IONP@PTX was evaluated by measuring the weight of liver and spleen in the mice.Results: Ultraviolet and visible absorption spectrometry analysis showed that PTX was successfully loaded onto IONP,and the drug loading calculated by the standard curve was 1mg/ml IONP@PTX solution containing 273.5μg PTX,which is quick release from IONP@PTX within 12 hours.The particle size analysis and TEM analysis showed that the hydrate diameter was around 36 nm and the core diameter was around 10 nm,with a zeta potential of-29 ± 7.65 m V.Using HMC3 and U251 cell models,it was confirmed that IONP@PTX exerted a killing effect on U251 cells,but had little effect on HMC3 cells compared with PTX alone.In addition,compared with PTX,IONP@PTX inhibited the capacity of cell migration and invasion,increased the concentration of iron ions and the levels of ROS and lipid peroxidation,and enhanced the expression levels of autophagy-related protein Beclin1 and suppressed ferroptosis-related protein GPX4 in vitro(P<0.05).Moreover,administration of IONP@PTX suppressed tumor volume of GBM xenografts and decreased the GPX4 protein in tumor tissues in comparison with control group(P<0.05).More importantly,IONP@PTX had little toxic effect on mice bearing the GBM xenograft.Intriguingly,inhibitory effect of IONP@PTX on GBM could be weakened by additional 3-MA or enhanced by additional rapamycin in vitro and in vivo(P<0.05).Conclusions: Iron oxide nanoparticles loaded with paclitaxel inhibit the growth of glioblastoma by ferroptosis pathway and are associated with the autophagy pathway.