Paclitaxel-loaded And 2-D G-labeled Iron Oxide Nanoparticles For Imaging And Therapy In Triple-negative Breast Cancer By Magnetic Resonance In Vivo

PurposeTo prepare monodisperse and long circulation Fe₃O₄@OA NPs modified with PLA-PEG,which can target high glucose metabolism tumor after2-deoxy-D-glucose（2-DG）linked to PLA-PEG.The nanoparticle was furtherfunctionalized when liposoluble chemotherapy drug paclitaxel（PTX）was loaded into OA layer to increase its anti-tumor effect.To investigate the feasibility of Fe₃O₄@OA-PTX@PLA-PEG-DG NPs in imaging and therapy in triple-negative breast cancer（TNBC）by MR,and to preliminarily evaluate its safety in vivo.Method（1）OA-coated Fe₃O₄ NPs were synthesized by thermal decompoadded.D-glucosamine is linked to PLA-PEG via amidationreaction.Fe₃O₄@OA-PTX@PLA-PEG-DG NPs were prepared after oleic acid layer loaded with PTX and wrapped with PLA-PEG-DG.These nanoparticles’characterizations were tested by transmission electron microscope,fourier transform infrared spectroscopy and thermogravimetric analysis.（2）Triple-negative breast cancer 4T1 bearing nude mice wereprepared.Tumor-bearing nude mice were injected with Fe₃O₄@OA@PLA-PEG NPs、Fe₃O₄@OA@PLA-PEG-DG NPs、Fe₃O₄@OA-PTX@PLA-PEG-DG NPs separately in 500μl sterile water suspension（0.5 mg Fe/ml,1.25 mg PTX/kg）,once every three days,three times altogether.Turbo-spin-echo weighted image（TSE-T2WI）、 multiecho spin echo pulse sequence and susceptibility weighted image（SWI）dynamic imaging of 4T1 breast cancer xenografts were taked preinjection and 1d、3d、6d、9d、12d,15d postinjection.T2 signal intensity（SI）and T2 value of 4T1 breast cancer Xenografts’tumor、liver and muscle were collected befor and after injection of these nanoparticles.Relative Enhancement Signal Intensity（rESI）of Xenografts’tumor between MRI T2WI and SWI after injection of Fe₃O₄@OA@PLA-PEG NPs、 Fe₃O₄@OA@PLA-PEG-DG NPs、Fe₃O₄@OA-PTX@PLA-PEG-DG NPs were compared.（3）Relative tumor volume and body weight of 4T1 breast cancer Xenografts were collected befor and after injection of Fe₃O₄@OA@PLA-PEG NPs、Fe₃O₄@OA@PLA-PEG-DG NPs、Fe₃O₄@OA-PTX@PLA-PEG-DG NPs,plot the RTV and weight curve.Prussian blue staining of 4T1 Xenografts tumor、liver、spleen、lung、heart and brain tissue sections after injection of these nanoparticles.Results（1）The Fe₃O₄@OA NPs were characterized with uniform size and good dispersion.After modified with PLA-PEG-DG on the surface,it has good water solubility,biocompatibility and superparamagnetization.The FT-IR spectrumwas indicate the successful linkage of D-glu-cosamine to the surface.The hydrodynamic diameter of of Fe₃O₄@OA@PLA-PEG-DG NPs is 62.7±2.3 nm,The hydrodynamic diameter of of Fe₃O₄@OA-PTX@PLA-PEG-DG NPs is 65.3±2.3 nm.The entrapment efficiency（EE%）of PTX was（82.6±2.3）%,And the loading rate of PTX was（0.4±0.2）%（2）The T2 signal intensity and T2 value of tumor decreased distinctly 1d、3d、6d after injection of Fe₃O₄@OA@PLA-PEG NPs and 1d、3d、6d、9d、12d,15d after injection of Fe₃O₄@OA@PLA-PEG-DG NPs、Fe₃O₄@OA-PTX@PLA-PEG-DG NPs.The T2 signal intensity in tumor 9 d after injection of Fe₃O₄@OA-PTX@PLA-PEG-DG NPs was significantly lower than the control group at the same time.The T2 signal intensity in tumor 12d、15d and the T2 value in tumor 9d、12d、15d of the two experimental groups were significantly lower than the control group.The SWI rESI was significantly lower than T2WI rESI 1、3、6d、9d、15d after injection of Fe₃O₄@OA@PLA-PEG NPs and 1d、3d、6d、9d、12d,15d after Injection of Fe₃O₄@OA@PLA-PEG-DG NPs、Fe₃O₄@OA-PTX@PLA-PEG-DG NPs.（3）The Fe₃O₄@OA-PTX@PLA-PEG-DG NPs had the strong inhibitory effect on tumor growth,and the RTV in this group was much smaller than the other two groups.The Fe₃O₄@OA@PLA-PEG-DG NPs showed no inhibitory effect on tumor growth.The body weight of mice in the three groups did not significantly change during the experimental time.（4）There were no blue granules in prussian-blue-stained tumor slices after injection of Fe₃O₄@OA@PLA-PEG NPs.More blue granules in prussian-blue-stained tumor slices were found after injection of Fe₃O₄@OA@PLA-PEG-DG NPs and Fe₃O₄@OA-PTX@PLA-PEG-DG NPs..Liver,spleen,myocardium,brain,lung and kidney slices all showed no obvious pathological damage.Conclusion（1）Fe₃O₄@OA@PLA-PEG-DG NPs and Fe₃O₄@OA-PTX@PLA-PEG-DG NPs showed active-targeting ability to TNBC in vivo.Both MRI T2WI and SWI could monitor the drug delivery process in vivo.Compared with T2WI,SWI were moresensitive to detect signal changes caused by iron oxide nanoparticles.（2）TNBC can be significantly repressed by Fe₃O₄@OA-PTX@PLA-PEG-DG,which works as a new treatment strategy.