Study On Photodynamic Therapy Of Oral Squamous Cell Carcinoma Based On An Aggregation-induced Emission Photosensitizer

Objective: Oral squamous cell carcinoma(OSCC)is the most common malignant disease in oral cavity.Currently,the treatment for OSCC mainly consists of surgical treatment alone or radiotherapy,and when it reaches advanced stage,surgery and/or radiotherapy combined with chemotherapy are required as adjuvant therapy.However,surgical treatment will cause facial structural and morphological defects and functional disorders,chemotherapy will cause systemic toxic side effects and drug resistance,so even if there is a good therapeutic effect,patients can still be very dissatisfied with the aesthetic and functional exercise after treatment.In order to overcome the limitations of traditional therapy,photodynamic therapy(PDT)has gradually entered the field of cancer treatment.This project aims at: 1.A photosensitizer(PS)with aggregation-induced luminescence stimulated by near infrared light was used to verify the binding ability of PS to OSCC cell lines and the ability to detect the production of Reactive oxygen species(ROS)in vitro cell experiments.2.Verify the biosafety of PS and the effect of photodynamic therapy on OSCC in mice,so as to provide a theoretical basis for promoting PDT as an adjunct therapy for OSCC.Methods: 1.In vitro experiments(1)Cell lines of experimental group and control group were cultured In vitro cell experiments,SCC cell lines were selected in the experimental group,and human oral keratinocyte epithelial(HOK)cell lines were selected in the control group.(2)The binding ability of PS to cell lines was detected PS was co-incubated with the two cell lines,and the binding ability of PS to the cell lines was observed under near-infrared microscope.(3)Compare the effects of PS on cell lines in light and dark environments.(1)MTT method was used to detect the cell survival rate at different time points after coincubation of PS with SCC and HOK at different concentrations in light and dark environments.(2)In the light and dark environments,the ROS generation ability of PS was detected by using ROS probe 2,7-dichlorofluorescein diacetate(DCFH-DA),and the killing ability of PS to the two kinds of cells was detected by using propidium iodide(PI).2.In vivo experiments(1)Verify the biosafety of PS Twenty mice were divided into the experimental group and the control group.PS was injected into the experimental group and PBS into the control group.Body weight changes of mice in the two groups were observed within 7 days.(2)To verify the therapeutic effect of PS in vivo Subcutaneous OSCC tumor model was established on the back of 20 mice and divided into 4 groups.Group A intratumoral injection of PBS without illumination;Group B was injected with PBS and illumination.Group C was injected with PS without illumination.Group D was injected with PS and light.The tumor size of the mice was recorded every other day,and the tumor site was dissected 15 days later.The treatment results of the 4 groups of tumors were compared,and the liver,kidney and tumor of two mouses in each group were taken for HE section.Results: 1.In vitro experiments After co-incubation of PS and SCC,bright fluorophore under n IR microscope showed that PS could effectively bind SCC cells.Dark toxicity and phototoxicity of PS to SCC and HOK cells were detected by MTT assay.The results showed that the survival rate of PS at 2.5,5,10,20 and 40μM co-incubated with the two kinds of cells for 20 min in dark environment was higher.After incubation for 4h,PS at 40μM showed mild toxicity.In the light environment,the cell survival rate of HOK combined with PS at different concentrations was still high,while the cell survival rate of SCC combined with PS decreased with the increase of PS concentration.When d CFH-DA and PI reagent were applied under two conditions,the bright green fluorescence and red fluorescence under fluorescence microscope showed the ROS generation ability and cell killing effect of PS,respectively.When no light was applied,there was no fluorescence imaging under the fluorescence microscope,which proved that PS did not generate ROS and cancer cells were not killed.2.In vivo experiments In toxicity test,body weight change,HE section and blood biochemical results of experimental and control mice showed no significant difference between the two groups,indicating a good biosafety of PS.Mouse tumor model is set up,in photodynamic therapy in mice,according to the results of internal PS injection combined with light group of mice with tumor relative to the size of the other three groups decreased greatly,and tumor tissues HE sliced results show that compared with the other three groups,the experimental group to surrounding cells,cancer cells with obvious necrosis foci nest also has decreased significantly.Conclusion: Through in vitro and in vivo experiments,we preliminarily verified that PS can produce ROS under specific light conditions,thus achieving the anticancer effect on OSCC.It showed good biocompatibility,excellent photostability and negligible dark toxicity in vivo.The preliminary exploration of PS in this study not only provides a theoretical basis for the development of more effective and mature PS,but also provides a new treatment plan for clinical application in collaboration with traditional treatment.