Liposomes Co-delivering Vincristine And C16 M Peg2000ceramide Inhibit Hepatocellular Carcinoma Cell Activity

Nanotechnology is a great breakthrough of the chemotherapy domain,nowit is a study focus,modification towards nanocarriers overcome the drawbacks of high cytotoxity and short circulation in vivo. Vincristine is a conventional agent of liver cancer,for it blocks autophagy maturation and damage the pro-survival autophagy process.Ceramide can induce mitophagy,which can degrade dysfunctional mitochondria,the combination of two drugs blocks pro-survival autophagy and induces cell death.In this study, the in vitro effect on two kinds of free drugs to the autophagy protein were determined, we found that VCR can inhibit the expression of LC3 and p62, suggesting that it inhibit the process of autophagy maturation, while the ceramide treatment increased the expression of LC3 and decreased p62 expression level, indicating an enhanced autophagy. Through combined effects of two drugs’ experimental results in vitro, we designed the liposome formulation. Then, we applied ethanol injection method and pH gradient method to achieve co-delivery of vincristine and ceramide, The liposome prepared were determined for nano characterization, judging the stability of liposomes. The cell toxicity experimes in vitro found nano drugs,including Lip-VCR-Cer and Lip-VCR perform a weaker kill effect on hepatocellular carcinoma cells than free VCR and free VCR+ceramide treatment. And for cell viability of different treatment periods,there is no significant difference. Unlike free drug, liposomes get into cells by endocytosis,which is associated with drug release. VCR and ceramide concentrations accumulate in tumor cells, improve drug utilization rate, increase cytotoxic effects upon cancer cells.However,free drugs manifest cytotoxicity rapidly.Killing effect of Lip-VCR-Cer is greater than Lip-VCR,free VCR+Ceramide has a stronger cytotoxity than free VCR, which may be related with ceramide.Maybe autophagy is involved. Ceramide can induce autophagy through specific signaling pathways in cells, causing increased expression of autophagy protein LC3, autophagy flux marker protein p62 decreased, play a protective role in preventing cells from death, making tumor cells to adapt to internal and external environmental stresses, to promote tumor growth. VCR can inhibit the pro-survival mechanism,lead to a failure to adapt to environmental stress and induce cell death. The existence of autophagy inducer enhances sensitivity of of tumor cells to chemotherapeutic drugs, achieves a etter cytotoxity of the combination of VCR with ceramide.Conclusion: There is no statistical significance in the basic characterization,in vitro release and in vitro cytotoxicity between Lip-VCR-Cer and Lip-VCR. In vitro cytotoxic effect,nano drugs is weaker than free VCR and free VCR+ceramide. The killing effect order in vitro of the four groups is:VCR+Ceramide >VCR > Lip-VCR-Cer > Lip-VCR. VCR combines with Ceramide enhanced the cytotoxic effect, which may be related to VCR,inhibiting the pro-survival role of autophagy. The antitumor effects of four drug treatment groups in vivo need to be verified by subsequent experiments.