| Due to the influence of the living environment and lifestyle,lung cancer has become one of the malignant tumors with the highest morbidity and mortality in the world,seriously threatening human health.The traditional methods of treating lung cancer include surgery,chemotherapy,and radiotherapy,but surgery is an invasive treatment,and there may be metastasis and recurrence after surgery;Chemotherapy and radiotherapy not only affect the tumor,but also affect normal tissues,and have large side effects on the human body.Therefore,it is urgent to seek better treatments.Photodynamic therapy has the characteristics of minimally invasive,small side effects,and local treatment.This kind of treatment that kills tumor cells while not damaging normal tissues and cells has attracted the interest of a large number of researchers.Like other treatments,photodynamic therapy also has limitations.The poor targeting,shallow penetration depth and hypoxic environment of photodynamic therapy have seriously affected the therapeutic effect,resulting in lower-than-expected curative effects.The unique advantages of nanomaterials provide the possibility to solve these problems.The main research contents of this paper are as follows:1.The chlorin e6 liposome particles Lip@Ce6 with uniform size and good dispersibility were prepared by thin film evaporation method,and their structure was characterized.Lip@Ce6 has a particle size of about 196 nm and an encapsulation efficiency of 94.2%.From the UV spectrophotometer detection of Ce6 and Lip@Ce6 absorption peaks,it can be seen that Ce6 is loaded on liposomes.2.Nude mice were subcutaneously inoculated with A549 lung cancer cells under the right forelimb,and after successfully constructing a tumor model,Lip@Ce6 and Ce6 were respectively configured into low,medium and high photosensitizer doses(2.5 mg/kg,5 mg/kg,10 mg/kg),Divided into six groups of photodynamic therapy groups.The model was injected into nude mice through the tail vein,and 1 hour after the injection of the drug,the photodynamic therapy was performed by percutaneously puncturing the fiber into the tumor.The experimental design was treated every three days for a total of five treatments.After completing five treatments,the changes in tumor volume of nude mice in each treatment group were analyzed.Each group of Lip@Ce6-PDT showed a better inhibitory effect on tumors than each group of Ce6-PDT.3.After completing the experiment,the nude mouse tumor tissue was obtained,histopathological section was performed on it,the degree of necrosis of tumor cells was observed by the HE staining result,and the expression of Bcl-2 and Bax was detected by the immunohistochemical result.The experimental results showed that the Lip@Ce6-PDT group had a higher degree of cell necrosis than the Ce6-PDT group,and the degree of necrosis continued to increase with the change of the photosensitizer concentration.Photodynamic therapy down-regulated the expression level of Bcl-2 and up-regulated the expression level of Bax,and the changes in the Lip@Ce6-PDT group were more obvious,which promoted cell apoptosis and achieved the therapeutic effect. |
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