【Abstract】ObjectiveTo construct a recombinant eukaryotic expression vector for human endostatin in order to study the inhibitory effect of liposome-mediated endostatin gene on the growth of human liver carcinoma in nude mice. MethodsHuman endostatin cDNA including IL-2 secreting peptide was cloned into eukaryotic expression plasmid pcDNA3.0 to construct recombinant plasmid pCD-sEndo. pCD-sEndo plasmid was transferred into hepatocarcinoma cell line SMMC-7721 mediated by liposome Dosper, the expression and secretion of endostatin gene was detected by RTPCR and Western blot analysis. The suspension of SMMC-7721 cells was injected subcutaneously at the back of 32 nude mice to establish the model of human liver carcinoma. The mice were divided into 4 groups randomly, and injected with Dosper+pCD-sEndo, Dosper+pcDNA3.0, Dosper and physiological brine separately. Tumor volume was measured by stages. The mice were executed after the drug had been given for 1 week, then the microvessel density (MVD) of the tumor tissue was detected with immunohistochemical method and apoptotic index of tumor cells was measured by TUNEL-stain. ResultsThe eukaryotic expression vector pCD-sEndo was successfully constructed and was confirmed by enzyme digestion and sequence analysis. Expression of endostatin gene was detected in transfected SMMS-7721 cells by RTPCR in vitro, and endostatin protein was also detected in the supernatant of transfected SMMS-7721 cells by Western blot. In vivo study, the growth of human liver carcinoma was inhibited in the group injected with endostatin gene: the average volume of tumor in this group was significantly smaller than that in other groups （P＜0.05）; the average MVD in this group was 6.2±2.5, significantly less than that in the group injected with physiological brine (32.8±6.4), Dosper （27.8±6.4）, or Dosper+pcDNA3.0 (25.5±5.5), P＜0.05. The average apoptotic index of tumor cells in treatment group, brine group, Dosper group and Desper+pcDNA3.0 group was 24.5±7.3, 7.6±2.5, 9.5±3.0 and 11.2±3.6 respectively, it was evidently higher in the treatment group than in the latter three groups. ConclusionHuman endostatin mediated by cation liposome could decrease the microvessel number of implanted human hepatocarcinoma in nude mice. It could also accelerate apoptosis of tumor cells and inhibit growth of tumor.
Objective To compare the transfection effects on soluble fms-like tyrosine kinase receptor-1 (sFlt-1) gene (2-4 transcellular region) mediated by carboxymethylated dextran coated nanoparticle and lipofectamineTM2000.Methods The plasmid pcDNA3.1-EGFP/sFlt-1(2-4) was constructed and assessed by enzyme cut, electrophoresis, and genetic sequencing. Three groups were divided: nanoparticle group, lipofectamine group, and non-transfected group. Twenty-four and 48 hours after the transfection, the distribution of cellular green fluorescence was oberved under the inverted phase contrast fluorescence microscope; the expression rate of green fluorescence was measured by flow cytometry; the expression of sFlt-1(2-4)mRNA and the protein was detected by reverse transcriptionpolymerase chain reaction (RT-PCR) and Western blot; the growth of the cells was observed by methyl thiazolyl tetrazolium (MTT) colorimetry and the relative growth rate (RGR) of the cells in each group was calculated; the cellular apoptosis in each group was detected by Hoechst staining.Results The sequence of sFlt-1(2-4) gene was equal to 915 base pair (bp).The transfection rate was 45% in nanoparticle group and 21% in lipofectamine group; the difference between the two groups was significant (t=2.541，Plt;0.05). Forty-eight hours after the transfection, the expression of sFlt-1（2-4）mRNA and protein was obviously higher in nanoparticle group than that in lipofectamine group (t=2.454，2.398；Plt;0.05) . Twenty-four and 48 hours after the transfection,the difference of RGR of the cells between nanoparticle and non-transfected group was not significant（t=1.436，Pgt;0.05）; the RGR in lipofectamine group differed much from that in non-transfected and nanoparticle group (t=2.412，2.545; Plt;0.05) ; the difference of cellular apoptosis was not significant between nanoparticle and nontransfected group (t=1.436，Pgt;0.05), but significant between nanoparticle and lipofectamine group (t=2.236，Plt;0.05). Conclusion The transfection rate of sFlt-1(2-4) mediated by carboxymethylated dextran coated nanoparticle was higher than that mediated by lipofectamineTM2000.
Liposomes with precisely controlled composition are usually used as membrane model systems to investigate the fundamental interactions of membrane components under well-defined conditions. Hydration method is the most common method for liposome formation which is found to be influenced by composition of the medium. In this paper, the effects of small alcohol (ethanol) on the hydration of lipid molecules and the formation of liposomes were investigated, as well as its coexistence with sodium chloride. It was found that ethanol showed the opposite effect to that of sodium chloride on the hydration of lipid molecules and the formation of liposomes. The presence of ethanol promoted the formation of liposomes within a certain range of ethanol content, but that of sodium chloride suppressed the liposome formation. By investigating the fluorescence intensity and continuity of the swelled membranes as a function of contents of ethanol and sodium chloride, it was found that sodium chloride and ethanol showed the additive effect on the hydration of lipid molecules when they coexisted in the medium. The results may provide some reference for the efficient preparation of liposomes.
Liposome is an ideal drug carrier with many advantages such as excellent biocompatibility, non-immunogenicity, and easy functionalization, and has been used for the clinical treatment of many diseases including tumors. For the treatment of tumors, liposome has some passive targeting capability, but the passive targeting effect alone is very limited in improving the drug enrichment in tumor tissues, and active targeting is an effective strategy to improve the drug enrichment. Therefore, active targeting liposome drug-carriers have been extensively studied for decades. In this paper, we review the research progresses on active targeting liposome drug-carriers based on the specific binding of the carriers to the surface of tumor cells, and summarize the opportunities, challenges and future prospects in this field.
OBJECTIVE: To study the therapeutic effect of Suyuping in which liposome is the main constituent on II degree burn wound. METHODS: From October 1998 to October 1999, 42 cases with II degree burn wound were adopted in this study. Among them, there were 30 males and 12 females, the average wound area was (23.4 +/- 9.7)%. The wounds on the left side of body were managed with sulfadiazine argentum(SD-Ag) while that on the right side with Suyuping. Healing and other situation about the burn wounds were observed and recorded at times. RESULTS: Forty-two patients completely healed when discharged from hospital. The average wound area managed with Suyuping was (11.2 +/- 7.3)% and the area with SD-Ag was (9.4 +/- 5.8)%. The mean healing time of Suyuping group was(18.4 +/- 4.7) days while that of SD-Ag was (23.5 +/- 7.9) days, there was significant difference(P lt; 0.05). Suyuping group presented few wound pain, allergy, bleeding and the side effect was less. CONCLUSION: Suyuping can accelerate wound healing and attenuate wound pain, allergy and bleeding, it is a potential and specific topical agent for treating II degree burn wound.
Objective To investigate the inhibitory effect of proliferation cell nuclear antigen (PCNA) antisense oligonucleotides mediated by liposome transfection on hepatocellular carcinoma cell proliferation. MethodsThe antisense oligonucleotides were complementary to 18mer sequences next to the start codon of PCNA mRNA sequences. The human hepatocellular carcinoma cell line Bel7404 was treated with antisense oligonucleotides. The inhibition of proliferation was estimated by MTT method. We compared the deference between the liposome mediated transfection technique and direct transfection technique. ResultsThe cell proliferation was inhibited effectively by antisense oligonucleotides. A sense sequence oligomer showed no effect.Liposome mediated transfection could enhance the inhibitory effect. Conclusion Liposome mediated transfection could enhance the inhibitory effect of PCNA antisense oligonucleotides on hepatocellular carcinoma cell proliferation.
Microvesicles (MVs) is small membrane vesicles released from different cell types under different conditions. Studies have shown that MVs may mediate vascular inflammation, angiogenesis, and other pathological processes. MVs may play an important role in the pathogenesis of diabetic retinopathy (DR) by mediating endothelial cell injury, thrombosis and neovascularization. The plasma MV level may be an effective parameter to monitor the development of DR. This article will summarize the research progress of the relationship between MVs and DR in recent years.
ObjectiveTo evaluate the therapeutic effect and adverse reaction of paclitaxel liposome combined with continuous infusion of large-dose 5-fluorouracil(5-fu) in treatment for advance gastric cancer(AGC). MethodsFrom May 2009 to August 2012, 63 consecutive patients with AGC in this hospital were enrolled in this study. All the patients were given chemotherapy including paclitaxel liposome and continuous infusion of large-dose(2.5 g/m2) 5-fu. The efficacy and toxicity of this regimen were observed. ResultsThere was no patient who could not tolerate adverse reaction related to such regimen. Five cases achieved complete response and 31 cases achieved partial response, the overall response rate was 57.1%(36/63). Hematologic toxicity included gradeⅢ/Ⅳleucopenia 8 cases(12.7%) and neutropenia 10 cases(15.9%), while there was no occurrence of gradeⅢ/Ⅳanemia or thrombopenia. Non-hematologic toxicity was fairly mild. ConclusionsPaclitaxel liposome is safe, well tolerated, highly targeted, and has long duration of effect. Paclitaxel liposome combined with continuous infusion of large-dose 5-fu is safe and effective in treatment for patients with AGC.
ObjectiveTo study the effect of Triton X-100 promoting liposome-mediated bone morphogenetic protein 2 (BMP-2) gene transfection of rat bone marrow mesenchymal stem cells (BMSCs). MethodsBMSCs were separated and cultured from the femur and tibia of healthy Wistar rats (8-week-old, male). The 3rd passage BMSCs identified by detecting the surface antigen were used to transfect. The optimum concentration of Triton X-100 for liposome mediated gene transfection was determined with ELISA meter by the way of MTT. In optimum concentration of Triton X-100, liposome mediated BMP-2 gene was transfected to BMSCs. The experiment was divided into 3 groups according to types of trasfection agents:BMSCs were transfected with Triton X-100+liposome+BMP-2 (experimental group), with liposome+ BMP-2 (conventional transfection group), and untransfected BMSCs served as blank control group. After 48 hours of transfecting, the green fluorescent protein (GFP) in cells was detected through inverted fluorescence microscope. After 72 hours of transfection, real-time fluorescence quantitative PCR was applied to measure the mRNA expression of BMP-2. Results0.01% Triton X-100 was determined to be the optimum concentration for not only making the BMSCs maintain vitality, but also achieving a certain effect on BMSCs. After trasfecting for 48 hours, GFP was observed through inverted fluorescence microscope in the experimental group and conventional transfection group, but was not observed in the blank control group. After trasfecting for 72 hours, the relative BMP-2 mRNA expression level was 5.94±0.12 in the experimental group, and was 4.99±0.08 in the conventional transfection group, showing significant difference (t=360.28, P=0.02). The transfection efficiency was increased by 19% in the experimental group. Conclusion0.010%Triton X-100 can promote the liposome mediated BMP-2 gene transfection of rat BMSCs, and can improve the transfection efficiency.
Objective To investigate the influence of cationic liposomemediated endostatin gene on colorectal cancer liver metastasis. Methods Animal model for colorectal carcinoma liver metastasis were established. The plasmid expressing endostatin genelipofectAMINE were injected in vein. Results After cationic liposomemediated endostatin gene were injected in vein, the incidence of liver metastasis and mean numbers of liver tumors were decreased, survival time of animal was significantly longer. Conclusion Intravenous injection of cationic liposomemediated endostatin gene can control the development of colorectal cancer liver metastasis effectively.