Study On SPIO-Ce6-loaded Liposomes For Magnetic Resonance Imaging And Photodynamic Therapy On Breast Cancer Cell

Objective To synthesize the Lipo(SPIO)formed by liposome and superparamagnetic iron oxide(SPIO),detect the T2 relaxivity of Lipo(SPIO)on magnetic resonance imaging(MRI),synthesize Lipo(SPIO-Ce6)complex developed by liposome,SPIO and chlorin e6(Ce6),and then explore the feasibility of Lipo(SPIO-Ce6)complex on photodynamic therapy(PDT)through vitro cell experimental research.Methods 1.SPIO and Ce6 co-loaded Lipo-based nanoparticle(Lipo(SPIO-Ce6))was prepared.The diameter and morphology of Lipo(SPIO-Ce6)were revealed by transmission electron icroscopy(TEM)and dynamic light scattering(DLS),respectively.The encapsulation efficiency of SPIO and Ce6 was determined by UV-vis spectrum.2.To measure the T2 signal intensity of Lipo(SPIO)on MRI.The EP tubes were divided into targeted experimental group and control group according to a series of concentrations of Lipo(SPIO).T2 relaxivity was measured on 3.0 T MRI.3.The safety of Lipo(SPIO)and Lipo(SPIO-Ce6)in vitro cytotoxicity was evaluated by the CCK-8 method.The human breast cancer cells MCF7 were divided into targeted experimental group and control group according to a series of concentrations of Lipo(SPIO)and Lipo(SPIO-Ce6).The cell viability of experimental hole was calculated according to optical density(OD)value tested by enzyme-labeled instrument.4.The fluorescence intensity of cell which absorbed the Lipo(SPIO-Ce6)was determined by fluorescence microscopy and flow cytometry.5.To study the effect of PDT of Lipo(SPIO-Ce6)for cancer cell in vitro cell experiments.The MCF7 cell were divided into targeted experimental group and control group according to a series of concentrations of Lipo(SPIO-Ce6).The generation of intracellular reactive oxygen species(ROS)of cancer cells after irradiating near infrared light(wave length 640 nm)was detected by using DCFH-DA probe.The cell viability of cancer cells after light irradiation was determined by using Calcein-AM/PI double stain kit.The induction and inhibition of cell proliferation after light irradiation was measured by using CCK-8 according to OD value.Results 1.The average diameter of nanocomposite measured by DLS was 116 nm,particle size distribution was 0.18.Nanocomposites were sphericity on TEM.Encapsulation efficiency of SPIO and Ce6 was 87 % and 60 % respectively.2.MRI result showed that T2 relaxation time of Lipo(SPIO)was related to the concentration of Fe in SPIO and the relaxation time decreased with the increase concentration of Fe.The relaxivity was 266 m M-1s-1.3.CCK-8 showed that the cell survival rate could arrive about 80 % under certain concentration of Lipo(SPIO)and Lipo(SPIO-Ce6)after culturing for 24 hours.4.The fluorescence microscopy and flow cytometry results showed that intracellular fluorescence intensity was proportional to the concentration of Lipo(SPIO-Ce6),which incidated that the fluorescence intensity enhanced with the increase concentration of Ce6.5.ROS assay kit result showed that intracellular fluorescence intensity was proportional to the concentration of Lipo(SPIO-Ce6),which reflected that the generation of intracellular ROS was related to concentration of Lipo(SPIO-Ce6).CCK-8 assay and Calcein-AM/PI double stain kit results showed that the number of death cells were increasing after irradiating near infrared light,while the control group cells remained alive well.Conclusion The Lipo(SPIO)developed in this study possesses excellent physicochemical properties and exhibited low toxicity and good biocompatibility.Additional,Lipo(SPIO)can be use as T2 contrast agent.Lipo(SPIO-Ce6)complex formed by Liposome,SPIO and Ce6 also exhibited low toxicity.Lipo(SPIO-Ce6)can generate ROS in vitro cell after light irradiation and have a strong killing effect for breast cancer MCF7 cells validated by vitro experiments.