Experimental Study Of Photodynamic Combined With Chemodynamic Therapy For Lung Cancer

Photodynamic therapy（PDT）is a new therapy with the advantages of minimally invasive,high selectivity and low systemic toxicity,which has been widely used in the treatment of solid tumors in recent years.However,the triggering conditions of photodynamic therapy and the characteristics of tumor microenvironment limit its clinical therapeutic effect.Among them,the hypoxic tumor microenvironment is one of the most important factors limiting the photodynamic effect.At present,the solutions to oxygen deficiency include the delivery of exogenous oxygen,internal oxygen production and the suppression of tumor respiration,among which the internal oxygen production method has the advantages of less side effects,not easy to leak in the middle,and so on,has become a research hotspot in recent years.The program of using manganese dioxide to promote hydrogen peroxide to produce oxygen in tumor can not only relieve tumor hypoxia,but also carry out chemodynamic therapy,realizing the combination of photodynamic and chemodynamic therapy.Based on the principle of photodynamic combined chemodynamic therapy,the effect of the proportion of each component on the therapeutic effect was studied quantitatively.The main research contents of this paper are as follows:1.Porphin E6（CE6）wrapped in liposome and PEG manganese dioxide nanoparticles were synthesized.The drug was characterized in terms of particle size,potential,ultraviolet absorption spectrum,etc.The results showed that CE6 was successfully coated in liposome and PEG manganese dioxide was successfully synthesized.2.The mouse model was constructed by injecting Lewis cells into the right back of the mice on the hind leg.After successful construction,the mice were divided into blank control group,model group,PDT group,and PDT+CDT group,where the concentration of photosensitizer in the PDT group was 2.5 mg/kg.PDT+CDT group was divided into 4groups according to the concentration of manganese dioxide without changing the concentration of photosensitizer 2.5 mg/kg:2.5 mg/kg,5 mg/kg,10 mg/kg,20 mg/kg.All the drugs were injected through the tail vein.The weight and tumor size of the mice were recorded before treatment,and the changes in tumor volume during treatment were analyzed.After treatment,pathological analysis was performed on the mice.In this study,five groups of different doses of Mn O₂ were observed.The results showed that when the concentration of manganese dioxide increased from 0 mg/kg to 20 mg/kg,the inhibitory effect of Mn O₂ on mice was increased,but when the concentration increased from 10mg/kg to 20 mg/kg,the inhibitory effect was not obvious.These results provide a theoretical basis for future clinical studies to master the optimal therapeutic dose of Mn O₂and Ce6 to reduce the toxic and side effects caused by overuse.