The Study On The Synthesis And Antitumor Activity Of New Ruthenium (?), Iridium (?) Complexes And Their Longcirculating Liposomes Preparations

Cancers have always been a worldwide medical problem with high recurrence rate and death rate,which make them incurable diseases.The main treatment methods currently used are surgical resection,chemotherapy and radiation therapy.In recent years,more and more patients choose chemotherapy with comprehensive consideration of various factors.At the same time,the researchers focus more on the field of chemotherapy for purpose of the exploration of high-efficiency and low-toxic chemotherapeutic drugs.At present,with the rapid development of diversified anti-tumor drugs,scientists have turned their attention to metal-based anticancer drugs and have made many breakthroughs,such as cisplatin and oxaliplatin.However,there are still many deficiencies in application.Therefore,it is urgent to develop new metal-based antitumor drugs with specificity,targeting,high-efficiency and low toxicity.In this paper,we have synthesized and purified a series of ruthenium???complexes and three series of iridium???complexes.According to the evaluation of cytotoxicity in vitro,we found that most of the complexes had certain toxicity on tumor cells for screening,then the in-depth mechanisms of antitumor were explored.However,three iridium???complexes were almost non-toxic against tumor cells.We developed them with lecithin and functional phospholipids for the purpose of long-circulating preparations with targeting,and evaluate mechanisms of their anti-tumor activity.The synthesized drugs were characterized by ESI-MS,IR,UV-vis,fluorescence spectra,scanning electron microscopy,particle size analyzer,¹H NMR,¹³C NMR,and their mechanisms of anti-tumor activity were also studied and discussed.In this paper,we mainly evaluate the antitumor activity and mechanisms of the synthesized drugs from the following aspects.Firstly,the cytotoxicity of the complexes was detected by MTT colorimetric method.We found that these complexes had a good inhibitory effect on the proliferation of the selected tumor cell lines.Based on DAPI,AO/EB staining and subcellular location experiments,we found that the complexes could enter the cells smoothly and cause morphological changes of tumor cells.Molecular docking was used to ivestigate the effect of drugs on DNA.Viscosity measurement experiments were conducted to analyze the effects of drugs on ctDNA.The comet assay was used to study the effect of complexes on DNA in tumor cells.The results showed that complexes could cause DNA damage and fragmentation.The effects of complexes on cell cycle and apoptosis were detected by flow cytometry.The studies showed that the mitotic arrest could be induced in a certain phase while apoptosis was also induced.The application of fluorescence microscopy,ImageXpress Micro XLS and flow cytometry on the detection of qualitative and quantitative analysis about intracellular calcium ion concentration,mitochondrial membrane potential,reactive oxygen content,autophagy,cytochrome c and tubulin.These results reveal that these complexes can cause an increase in the intracellular Ca²⁺concentration,a decrease in mitochondrial membrane potential,the generation of reactive oxygen species and the release of cytochrome c.In addition,the complexes could inhibit the polymerization of microtubule protein resulting in blocking the mitosis process of tumor cells.And there were some complexes that could cause autophagy in tumor cells.The results of Transwell assay showed that,to a certain extent,the complex inhibited the invasion ability of tumor cells.Finally,according to the western blot experiment,the signal pathways of apoptosis induced by complexes were explored.The results showed that complexes could inhibit the expression of proteins in the PI3K/AKT/mTOR pathway,activate the pro-apoptotic protein Bax,Bid and Bad of Bcl-2 family,and inhibit the expression of anti-apoptotic protein Bcl-2 and Bcl-x.The detection of Cytochrome C showed that the complexes could release the apoptosis-related active substances in mitochondria and cause cascade reactions of caspase family proteins,thereby leading to cell apoptosis.In summary,these ruthenium???and iridium???complexes can inhibit the proliferation of tumor cells and induce apoptosis through ROS-mediated mitochondrial apoptotic pathway and Akt/mTOR signaling pathway,and can effectively inhibit tumor invasion.