二氢卟吩e6脂质体介导的光动力疗法治疗肺癌的动物实验研究

Photodynamic Therapy of Lung Cancer Mediated by Chlorin e6 Liposome:An Experimental Study

目的研究二氢卟吩e6(chlorin e6,Ce6)及Ce6脂质体(Liposomes)对肺癌的光动力作用效果。方法采用薄膜蒸发法制备Lip@Ce6,检测其表征、形态、包封率。将45只实验裸鼠随机分为9组,每组5只,分别为空白对照组、模型对照组(A组)、激光组(B组)、Ce6-PDT组根据光敏剂浓度2.5 mg/kg、5 mg/kg、10 mg/kg设置三组(C1组、C2组、C3组)、Lip@Ce6-PDT组根据光敏剂浓度2.5 mg/kg、5 mg/kg、10 mg/kg设置三组(D1组、D2组、D3组)。给药1 h后经皮穿刺导入光纤行瘤内组织激光照射治疗,激光波长665 nm,治疗10 min/次,每3 d治疗1次,共治疗5次。通过绘制瘤体体积生长曲线、计算抑瘤率,分析光动力疗法(Photodynamic therapy)对肺癌的抑制作用;常规HE染色,在光镜下观察肿瘤组织病理学的变化并对实验结果进行分析。结果 (1)实验制得的Lip@Ce6的粒径为196.3 nm左右,具有良好的分散性和稳定性,Ce6的包封率为94.2%。(2)肿瘤增长速率为A组>B组>C1组>D1组>C2组>D2组>C3组>D3组;前三次PDT治疗后差异无统计学意义(P>0.05);从第四次治疗后,各组差异具有统计学意义(P<0.05);第五次治疗后,B组、C1组、C2组、C3组、D1组、D2组、D3各组的抑瘤率分别为15.3%、31.3%、40.3%、46.5%、35.9%、45.1%、53.9%。(3)组织病理学改变,光镜下观察到各组呈现不同程度的坏死,且Lip@Ce6-PDT各组比Ce6-PDT各组的坏死程度高。结论本研究成功制备了纳米光敏剂Lip@Ce6,相比于普通光敏剂Ce6可更有效的抑制瘤体的生长,增强细胞坏死程度。

Objective To study the photodynamic effects of Chlorin e6(Ce6)and Ce6 liposomes on lung cancer.Methods Lip@Ce6 were prepared via thin film evaporation,and its characterization,morphology and encapsulation rate were detected.Totally 45 experimental nude mice were randomly divided into 9 groups(5 mice in each group):the blank control group,model control group(group A),laser group(group B),3 Ce6-PDT groups(group C1,C2 and C3),which were formed by photosensitizer concentrations(2.5 mg/kg,5 mg/kg and 10 mg/kg)and 3 Lip@Ce6-PDT groups(group D1,D2 and D3),which were formed by photosensitizer concentrations(2.5 mg/kg,5 mg/kg and 10 mg/kg).Upon the administration of the photosensitizer for an hour,665 nm percutaneous fiber laser was introduced into the tumor for an irradiation of 10 min.The treatment was conducted 5 times in total at an interval of 2 days.The inhibition effect of photodynamic therapy on lung cancer was analyzed by drawing the tumor volume growth curve and calculating the tumor inhibition rate.Routine HE staining was performed to observe the morphological changes of tumor tissues under a light microscope and the experimental results were analyzed.Results(1)Lip@Ce6 had a particle size of about 196.3 nm,with good dispersion and stability,and the encapsulation rate of Ce6 was about 94.2%.(2)The tumor growth rates declined in the following order:group A,group B,group C1,group D1,group C2,group D2,group C3 and group D3.There was no significant difference in tumor growth rate between different groups after the first three treatments(P>0.05),but remarkable differences appeared after the fourth treatment(P<0.05).The tumor inhibition rates of these groups were 15.3%,31.3%,40.3%,46.5%,35.9%,45.1%and 53.9%.(3)Histopathological changes were observed.Different degrees of necrosis were observed under light microscope in each group,and the degree of necrosis in Lip@Ce6-PDT groups was higher than that of Ce6-PDT groups.Conclusions Nano photosensitizer Lip@Ce6 was successfully prepared.Compared with ordinary photosensitizer Ce6,it inhibited the growth of the tumor more effectively,enhanced the degree of cell necrosis,and improved the efficacy of photodynamic therapy for lung cancer.