Studies On The In Vitro Photodynamic Therapy And Magnetic Resonance Imaging Of Polyethylene Glycol And Ferroferric Oxide-Two Chlorines Nanocomposites

Objective This paper is a synthesis of water-soluble ferroferric oxide nano cube（Fe₃O₄）,And Ce6was loaded onto Fe₃O₄， forming a Fe₃O₄-PEG-Ce6complex, which isused for photodynamic therapy and magnetic resonance imaging （MRI）.Methods①Synthesize a multi-functional ferriferrous oxide（Fe₃O₄）, which is thenfunctionalized by a biocompatible polyethylene glycol （PEG） polymer to acquire highstability in physiological solutions and TEM, series of characterization of the Fe₃O₄-PEGcomplex.②Study the application of water soluble Fe₃O₄-PEG nanoparticle in magneticresonance imaging. Study on the magnetic properties、cytotoxicity and MRI imaging ofnano cube,.③Fe₃O₄-PEG nanocubes was injected through the tail vein of mouseimplantation of murine breast cancer cell line4T1, scanning in3T MRI, observingcomplex in the tumor region enrichment effect, observing the effect of imaging at differenttime points.④Chlorin（Ce6）was loaded onto Fe₃O₄-PEG, forming a Fe₃O₄-PEG-Ce6complex。and the NV-Vis was used to determine of drug loading rate is3.38%.⑤SOSGwas introduced to measure the generation of singlet oxygen under light irradiation of704nm at a power density of5mW/cm2.⑥The Fe₃O₄-PEG-Ce6, Fe₃O₄-PEG, Ce6and4T1cells were incubated with24h and irradiated by light of704nm at a power density of5mW/cm2for30min and in vitro cytotoxicity and cell toxicity were tested after tumorcells incubation detection of nanometer anticancer therapeutic effect..Results①The synthesized PEG-Fe₃O₄showed uniform size,narrow particle sizediatribution, good dispersion. The size of nanocube, size is30⁴0nm. complex in the cellculture fluid, serum solution showed better stability.②The water soluble Fe₃O₄-PEG nanocubes has magnetic properties and goodbiocomparability, which can reduce the T₂signal in MRI. As T₂contrast agent in magnetic resonance imaging, the synthesized nanocube may provide magnetic for human clinicalexperiment.③18hours after intravenous injection of Fe₃O₄-PEG nanocubes, tumorsshowed obvious darjen effect in MRI.④Different concentrations of Fe₃O₄-PEG-Ce6UV-vis spectra analysis showed that Ce6was successfully loaded up and drug loadingexperiments showed that the maximum load of Ce6for3.38%.⑤Fe₃O₄-PEG-Ce6andSOSG mixed liquid produced Singlet oxygen is lower than that of Ce6, higher than SOSG,indicating that Fe₃O₄-PEG-Ce6can produce Singlet oxygen, but lower than that ofCe6.⑥In Ce6loaded, in dark conditions, Fe₃O₄-PEG-Ce6, Fe₃O₄-PEG, Ce6in highconcentration was not observed obvious toxicity However, after culturing with4T1cellsfor24h and laser irradiation in the UV （704nm,5mW/cm2）, Fe₃O₄-PEG-Ce6can killcancer cells effectively while Fe₃O₄-PEG showed no obvious cytotoxicity to4T1cellswith/without laser irradiation..Conclusion The Fe₃O₄-PEG-Ce6was stable in physiological environments、cube shapedand exhibited no obvious in vitro toxicity to cells at the tested concentrations.Fe₃O₄-PEG complexes can be used as T₂contrast agent MRI, Fe₃O₄-PEG-Ce6complex toproduce singlet oxygen formation in the loading of Ce6, and complex relatively non-toxic.In the in vitro photodynamic therapy,compared with common free photosensitizer Ce6,Fe₃O₄-PEG-Ce6on tumor cell killing effect was significant.