The Experimental Study On The Effect Of Radionuclide Nanoliposome In The Treatment Of Cervical Cancer

Objective: Radioactive iodine therapy is a conventional treatment of hyperthyroidism and differentiated thyroid carcinoma,but non thyroid tumor cells can not take up free ¹³¹I.Previous researchs showed radioiodine therapy of non thyroid tumor cells have poor targeting and short retention times,but this problem could be solved by unclear nanoparticles.However,previous studies had also found that the radionuclide nanoparticles had poor therapeutic effects in animal experiments,because the unit mass carrier could carry the limited amount of ¹³¹I.In this study,to improve the ¹³¹I carrying capacity of the unit liposomes,we intend to use ¹³¹I labeled tyrosine random polypeptide chain and wrapped in the nano liposome to prepare the novel multifunctional radionuclide liposomes,and the experiment was carried out in cervical cancer He La cells and nude mice model.Methods: Comparing the difference of the two methods that nano-liposome encapsulated ¹³¹I labeled tyrosine peptide and ¹³¹I direct labeling of nano-liposomes in cervical cancer cells in both vitro and vivo,we intend to provide a new perspective for the preparation of radionuclide nano liposome and a new treatment for cervical cancer.Results: The first part of this study is to construct the radionuclide nano liposome and analyse the maximum amount of marker,labeling rate and radiochemical purity of unit nano-liposome by paper chromatography.The second part is the study of the He La cellular level: 1)to observe the targeted binding ability and cell uptake capacity by confocal microscopy;2)to carry out iodine uptake test,and evaluate the ¹³¹I retention time and the amount;3)to observe the effect of liposome on apoptosis and the killing effect by flow cytometry.The third part of this study is animal experiment: 1)a nude mouse model of cervical cancer is constructed by 3-4 week old female nude mice;2)to determinate the tissue distribution of nano liposome in nude mice by gamma counter;3)to observed the localization of nano liposome RGD-¹³¹I-TPC-L in nude mice by SPECT/CT tomography;4)to study the therapeutic effects of each treatment group : RGD-¹³¹I-TPC-L,RGD-L-¹³¹I,¹³¹I and normal saline group.Result: This study synthesizes two kinds of radionuclide nano-liposome RGD-¹³¹I-TPC-L and ¹³¹I-RGD-L successfully.Maximum labeling and labeling rate of this two kinds of radionuclide nano liposomes are?6.3±0.8m Ci VS 2.7±0.6m Ci?,?85.3±7.4% VS 72.5±9.8%?,respectively,by unit nano liposomes?P<0.05?.At the cellular level experiment,confocal microscopy experiments show that He La cells have uptake of nano-liposomes.While the radioactivity counts in the free ¹³¹I group are always at very low levels in He La cells.The IC₅₀ values of RGD-¹³¹I-TPC-L and ¹³¹I-RGD-L are 43.6 and 50.3?Ci,respectively.Under the same dose 50 Ci ¹³¹I,the apoptotic rates of Hela cells in the free Na¹³¹I,RGD-¹³¹I-TPC-L and ¹³¹I-RGD-L group are 5.1 ± 0.39%,10.3 ± 0.67% and 11.9 ± 0.40%,respectively?P<0.05?.In the animal level experiment,after 24 h,48h,72 h of the intratumoral injection in cervical cancer nude mice,the uptake rate of tumor tissue in free Na¹³¹I,RGD-¹³¹I-TPC-L and ¹³¹I-RGD-L group are?0.41 ± 0.12% ID / g,0.31 ± 0.08% ID / g,0.29 ± 0.10% ID / g?VS?25.71 ± 5.13% ID / g,17.47 ± 3.43% ID / g,8.75 ± 2.64% ID / g?VS?19.73 ± 4.66% ID / g,9.92 ± 2.11% ID / g,3.60 ± 1.03%ID / g?,respectively?P<0.05?.SPECT/CT imaging shows that RGD-¹³¹I-TPC-L and ¹³¹I-RGD-L are both clearly more visible in the tumor and has a longer retention time than free Na¹³¹I.In terms of curative effect,the growth of tumor volume in RGD-¹³¹I-TPC-L group and ¹³¹I-RGD-L are inhibited,and the weight loss of mice decreased.Pathological sections of HE staining show that the main organs of the nude mice have no obvious tissue damage,under tumor tissue microscopy,RGD-¹³¹I-TPC-L group shows greater tumor cell degeneration and necrosis than ¹³¹I-RGD-L.Conclusion: RGD-¹³¹I-TPC-L have higher maximum labeling and labeling rates than ¹³¹I-RGD-L,has a better labeling effect than directly labeled with ¹³¹I on the surface of nano-liposome,and it can be used to build nuclide nano liposomes in future.RGD-¹³¹I-TPC-L can inhibit tumor growth in cervical cancer cells and nude mice model,and can provide new ideas for cervical cancer treatment.