| Cancer is one of the largest global public health problems, and has become a serious threat to human health. As a developing country, C hina’s cancer morbidity and mortality increased year by year. Because of the big side effects of conventional chemotherapy drugs, the development of new anti-tumor agents is important. Isoquinoline derivatives are a class of compounds with antitumor activity, but ha ve low water solubility, difficult absorption, and there direct administration effect is poor. This research is mainly with isoquinoline derivatives screening of antitumor activity, and the development of drug delivery system in order to improve the drug absorption and reduce side effects.The main contents of this paper include the following aspects:1. Antitumor activity screening and detection of physical and chemical properties.In this paper, 11 kinds of isoquinoline derivatives and α-methylene-γ-butyrolactone derivatives have been screened by MTT assay to selecet anti-tumor compound. IC50 experiments in He La and Hep G2 cells and inhib ition experiments in HEK-293 T cells showed that 2-[[4-Bromo-2-(4-bromo-benzoyl)-1-cyano-1,2-dihydro-isoquinolin-1- yl]-(2-bromo-phenyl)- methyl]-acrylic acid menthyl ester(Compound 2)had stronger inhibitory effects on tumor cells but not in normal cells in vitro. Then this compound was selected as an antitumor drug for further research. Physical and chemic al properties of this compound showed that the compounds insoluble in water, slightly soluble in ethanol(1.52 mg/m L). It’s difficult to be directly applied to clinical treatment.2. Establishing liposomes and transferrin conjuncated liposomes drug systemDue to Compound 2 is insoluble in water and slightly soluble in ethanol,we chose liposome to load it. And due to the transferrin receptor expression increased in most tumor cell surface, we modified liposomes with transferring as transferrin-conjugated liposomes. We have studied physicochemical properties of liposomes and transferrin liposomes. Then the transferrin concentration and drug loading optimization study showed that the optimization conditions of liposome preparation obtained as LP: Tf = 500: 1 and drug loading 10%. The particle size of prepared liposomes was about 77 nm, and transferrin liposome was about 144 nm. The zeta potential was no significant difference between two liposomes in the range of-7 ~-4 m V.3. Liposomes, transferrin liposomes evaluation in vitroIn this paper, we prepared liposomes and transferrin liposome s and evaluated them in vitro. The serum stability test and in vitro drug release test found that both systems were able to maintain stability in the serum environment, and could reach a certain release effect. Flow cytometry and confocal results were shown in both tumor cell lines, transfection efficiency of Tf-LPs was significantly higher than LPs which declared that transferrin conjugated liposomes could enhance transfection efficiency, and be helpful to improve cellular uptake efficiency in tumor cells. The results of the cellular uptake pathways study preliminary demonstrated that Tf- LPs system delivering drug into tumor cells was mainly via transferrin receptor- mediated endocytic pathway. MTT assay showed that Tf- LPs cell inhibition was stronger than LPs in the tumor cells He La and Hep G2. Investigation results of the level o f ROS and mitochondrial membrane potential study also showed that Tf- LPs could induce ROS levels increasing, and the tumor cel s underwent apoptosis.In summary, the transferrin conjugated liposomes delivering a novel compound has potential for tumor therapy. Compounds have been screened for good anti-tumor activity. The transferrin liposome entrapped selected compond can overcome the poor compound solubility, low bioavailability characteristics. And it can extend the cycle time, target to tumor cells. Transferrin liposome prepared for delivery of novel compounds could lay a solid foundation for the further research work in vivo. |
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