923564-51-6 br The apoptosis of Ct
The apoptosis of Ct26 923564-51-6 was investigated using Annexin-V-FITC and PI assay, quantified by FCM and the representative images are shown in Fig. 6B. The apoptosis rate was 45% in cells treated with MP/ PPPD micelles, and 6% in the control group. This result indicated that MP/PPPD micelles have a pronounced eﬀect of inducing apoptosis in the anti-tumor activity.
3.4. Antitumor eﬀect of MP/PPPD micelles in vivo
The mice subcutaneous tumor model was build and treated with 5% Glucose solution (GS), PPPD micelles, pVax/PPPD and MP/PPPD mi-celles. The data of tumor volumes, weight and body weight of mice were collected and plotted in Fig. 7. After treatment of MP/DPPP mi-celles, the tumor volumes measured were obviously were smaller than other groups 20 days later. Meanwhile, the weights of tumor collected
Fig. 5. Transfection eﬃciency test of MP/DPPP. DPPP containing pEGFP (4 μg) was used to transfect CT26 cells at a weight ratio of 1:150 pEGFP to DPPP. The transfection eﬃciency was measured by fluorescence microscopy A) and flow cytometry after 24 h B); Detection of MP from diﬀerent groups by RT-PCR C). The results represent three independent experiments.
from mice after sacrifice in the MP/PPPD micelles group were lighter. The body weights of mice from these groups were not significant dif-ferent (P > 0.05). These results indicated that MP/DMP micelles could inhibit the growth of colon tumor in vivo without obvious drug toxicity.
In addition, the nude mice peritoneal tumor model was also applied for evaluation of anti-tumor eﬀect of MP/PPPD micelles in vivo. The results are plotted in Fig. 8 and are similar with the results in the subcutaneous tumor model. Tumor node and weights were both smaller and lighter in the group treated with MP/DPPP micelles than other groups at predominant time points. The weights of mice did not diﬀer much among groups. We could conclude the inhibition of colon tumor by MP/PPPD micelles was prominent in the peritoneal tumor model and consistent with the result in the subcutaneous tumor model.
The mechanisms relating to tumor proliferation, angiogenesis and apoptosis were also explored by Ki-67 and TUNEL assay. Representative images are shown in Fig. 9. The Ki-67 positive cells were fewer under fluorescence microscope in the MP/PPPD micelles group than other groups. In addition, number of apoptotic cells in the MP/PPPD micelles group was much more than other groups. Results of these tests in-dicated that MP/PPPD micelles could eﬀectively inhibit the cell pro-liferation and induce the apoptosis of colon tumor cells in vivo.
3.5. Safety evaluation of MP/DMP micelles
Histopathological analyses of internal oragans (heart, liver, spleen, lung and kidney) were performed after sacrifice of mice from diﬀerent goups. They were sectioned into slides and stained with HE. Vital organ sections all showed normal histological morphology in MP/PPPD group and no toxicity was found. In addition, no obvious toxicities were ob-served in the mice, as determined by hematological index (Fig. 10).
As a representative of oncolytic viruses, the VSV has been widely researched and demonstrated to have prominent anti-cancer ability. It kill cancer cells by direct cell lysis and activation of immune response against tumor cells [13–16]. However, the activated immune response will also prompt the inherent defense of immunocytes against VSV si-multaneously, such as mature plasmacytoid dendritic cells, causing the rapid clearance of VSV within days, which greatly reduce the anti-tumor eﬀect [21,22]. Moreover, the large dose use of VSV should be avoided since virus-ralated toxicity has been reported, such as blister-like lesions on skin, hepatotoxicity, respiratory toxicity and so on [23–25]. Researches showed the MP played a vital role during the process of VSV infection and corresponding cytopathic eﬀects. This MP synthesized in host cells was reported to have a potent anti-cancer ac-tivity through a variety of mechanisms. It is responsible for cell rouding after infection of viral, host cell apoptosis and is the viral component that shuts down the gene expression of host cells on the level of tran-scription and prohibited the synthesis of proteins [26–28]. Developing a well designed non-viral MP gene delivery system for cancer treatment will derive the advantage and overcome the drawback of VSV.
Safe and eﬃcient non-viral gene delivery system is still under re-search. The cationic liposome DOTAP is a widely used cationic carrier and has been proved by Food and Drug Administration (FDA) . However, it is prone to aggregate in circulation and eliminated due to first pass eﬀect, leading to a poor anti-cancer eﬀect in vivo. Further-more, its excessive charge on surface usually destroy cytomembrane of normal cells, limiting its further application in clinical treatment. In order to decrease the toxicity, the amphiphilic cationic polymer PEG was linked to DOTAP to regulate the physicochemical property and prevent aggregation in fluid, without compromising the gene delivery eﬃciency . We previously formulated a novel gene-delivery system