OBJECTIVETo evaluate the effects of polyamidoamine dendrimer (PAMAM) liposome as gene carriers on the cellular uptake and its cytotoxicity in colonic cancer cell.

METHODSThe liposome modified PAMAM was synthesized with liposome and polyamidoamine dendrimer. Plasmid PEGFP-N1 was mixed with the liposome-modified PAMAM or unmodified PAMAM to form nanoparticle complexes. The shape and size of the nanoparticle complexes were observed by transmission electron microscope and the zeta potential was measured by analytical tool. The encapsulating efficiency was determined by ultraviolet spectrophotometer in centrifuging method. After the cell lines SW620 (colonic cancer cell), MCF-7 (breast cancer cell), ECV304 (vascular endothelial cell) were transfected by the two kinds of PAMAM nanoparticle complexes, the flow cytometry was used to determine the uptake of enhanced green fluorescent protein (EGFP) gene. The cytotoxicity of PAMAM liposome nanoparticles and PAMAM nanoparticles was evaluated by MTT assay.

RESULTSThe diameter of liposome modified PAMAM complex was (192 ± 16) nm, and that of PAMAM complex was (189 ± 19) nm (P > 0.05); and the zeta potential of liposome modified PAMAM complex was higher than that of PAMAM complex [(42 ± 7) mV vs. (32 ± 7) mV, P < 0.05]. There was no significant difference in envelopment rate between the two groups [(82 ± 7)% vs. (84 ± 6)%, P > 0.05]. After the colonic cancer cell line SW620 was transfected with the two kinds of PAMAM nanoparticle complexes, the cellular uptake of the cells with the liposome-modified PAMAM complex was significantly higher than that of the cell with PAMAM complex (P < 0.05). The cellular survival rate of the cell lines with liposome-modified PAMAM complex was significantly higher than that of cell lines with PAMAM complex (P < 0.05).

CONCLUSIONThe liposome modified PAMAM can improve gene transfection efficiency and suppress its cytotoxicity.

Cell Line, Tumor ; Cell Survival ; drug effects ; Colonic Neoplasms ; metabolism ; pathology ; Dendrimers ; pharmacokinetics ; toxicity ; Genetic Vectors ; pharmacokinetics ; toxicity ; Humans ; Liposomes ; pharmacokinetics ; toxicity ; Transfection

The biosafety of gene delivery vectors has received much more attention in recent years. In this article, the biosafety of non-viral gene delivery vectors was mainly discussed. Recent developments in researches on toxicity, nano-effect, blood compatibility and immune response of non-viral gene delivery vectors were reviewed.
Cations ; chemistry ; Drug Delivery Systems ; methods ; Gene Transfer Techniques ; Genetic Therapy ; methods ; Genetic Vectors ; immunology ; pharmacokinetics ; toxicity ; Humans ; Nanoparticles ; chemistry

In order to construct a novel fusion protein PTD-maxadilan (PTD-MAX) that can enter the blood-brain barrier (BBB) efficiently, a new gene encoding PTD-MAX was synthesized and cloned into the expression vector pKYB. The recombinant vector pKYB-PTD-MAX was transformed into Escherichia coli ER2566. The expression of fusion protein consisting of PTD-MAX, intein and chitin binding domain was induced by IPTG and the target PTD-MAX protein was purified using Intein Mediated Purification with an Affinity Chitin-binding Tag system. The molecular weight of PTD-MAX determined by the laser flight mass spectrometry was coherent with its theoretical value. The results of the experiment in vivo indicated that the recombinant PTD-MAX can permeate into BBS and inhibitory effects on the food intake were more significantly than maxadilan (P<0.05). The preparation of PTD-MAX lay the foundation for its further application.
Animals ; Base Sequence ; Blood-Brain Barrier ; metabolism ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; genetics ; Insect Proteins ; biosynthesis ; genetics ; pharmacokinetics ; Mice ; Molecular Sequence Data ; Protein Structure, Tertiary ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; pharmacokinetics ; Vasodilator Agents ; metabolism ; pharmacokinetics

In this research was developed high efficiency method using 125I for directly labeling KH901, a tumor-specific oncolytic recombinant adenovirus, biodistribution of 125I-labeled compound in normal mice was investigated. 125I-KH901 was prepared by N-bromosuccinimide labeling method to find the optimal ratio of labeling response. The compounds were isolated and purified by Sephadex-G10 agarose and the radiochemical purity of compounds was analyzed by paper chromatography. The radioactivity biodistribution in mice was measured at different times after caudal vein injection with 0.1ml 125I-KH901. The labeling yield of 125I-KH901 was 78% and the radiochemical purity was 95% after purification by Sephadex-G10 agarose. Biodistribution revealed that the uptake of 125I-KH901 in liver was higher than in other organs at all time points of the experiment. 125I-KH901 was mainly concentrated in liver, kidneys, spleen and lung. It can be seen that N-bromosuccinimide labeling method is an optimal method with simple steps and high labeling yield in labeling KH901 with 125I. 125I-KH901 has a biodistribution trait which is an advantage to treating liver tumors.
Adenoviridae ; genetics ; physiology ; Animals ; DNA, Recombinant ; genetics ; Female ; Genetic Vectors ; genetics ; Iodine Radioisotopes ; pharmacokinetics ; Male ; Mice ; Mice, Inbred BALB C ; Oncolytic Viruses ; genetics ; physiology

To prepare a kind of effective non-viral transduction vector, which can deliver exogenous gene into the brain, this vector can be injected through vein system and has the ability to penetrate blood brain barrier. Several groups of materials proportion, type of oil phase, water-oil ratio, phosphatides-cholesterol ratio, temperature of steaming, ultrasonic temperature and time were compared for optimization. Well-constructed immunoliposomes encapsuling LacZ gene were infused into rats through tail vein. 48 h after injection, expression product beta-galactosidase of LacZ gene was detected by histochemistry staining to convince the validity of immunoliposomes as non-viral vectors. The best proportion of synthesis immunoliposomes is as following: phosphatides-cholesterol ratio is 1:1, lipids/drug is 100:1, the type of oil phrase is dichloromethane, oil-water ratio is 4:1, temperature of steaming is 30 degrees C, ultrasonic temperature and time is 10 degrees C and 5 min. At last, 10% trehalose was added as a stabilizer. The entrapment rate is 87.24% and antibody coupling rate is 69%. When immunoliposomes were infused into rats, the expression of LacZ gene could be observed in the brain and periphery organs. Through the best proportion of materials, gene delivering immunoliposomes had been synthesized successfully. This non-viral vector can deliver exogenous gene penetrating blood brain barrier and express in the brain, and will be well-used in the field of gene therapy of cerebral diseases.
Animals ; Antibodies, Monoclonal ; administration & dosage ; pharmacokinetics ; Blood-Brain Barrier ; Brain ; blood supply ; immunology ; metabolism ; Drug Delivery Systems ; methods ; Genetic Vectors ; Lac Operon ; genetics ; Liposomes ; administration & dosage ; immunology ; pharmacokinetics ; Male ; Particle Size ; Plasmids ; Polyethylene Glycols ; administration & dosage ; pharmacokinetics ; Rats ; Receptors, Transferrin ; immunology ; Tissue Distribution ; beta-Galactosidase ; genetics ; metabolism

The delivery of transgenes to the central nervous system (CNS) can be a valuable tool to treat CNS diseases. Various systems for the delivery to the CNS have been developed; vascular delivery of viral vectors being most recent. Here, we investigated gene transfer to the CNS by intravenous injection of recombinant adenoviral vectors, containing green fluorescence protein (GFP) as a reporter gene. Expression of GFP was first observed 6 days after the gene transfer, peaked at 14 days, and almost diminished after 28 days. The observed expression of GFP in the CNS was highly localized to hippocampal CA regions of cerebral neocortex, inferior colliculus of midbrain, and granular cell and Purkinje cell layers of cerebellum. It is concluded that intravenous delivery of adenoviral vectors can be used for gene delivery to the CNS, and hence the technique could be beneficial to gene therapy.
Adenoviruses, Human/isolation & purification* ; Animals ; Blood-Brain Barrier ; Brain/virology* ; Cerebellum/cytology ; Cerebellum/virology ; Comparative Study ; Female ; Genes, Reporter ; Genetic Vectors/administration & dosage ; Genetic Vectors/isolation & purification ; Genetic Vectors/pharmacokinetics* ; Hippocampus/virology ; Inferior Colliculus/virology ; Injections, Intravenous ; Luminescent Proteins/analysis ; Luminescent Proteins/biosynthesis ; Luminescent Proteins/genetics ; Mice ; Mice, Inbred BALB C ; Neuroglia/virology ; Neurons/virology* ; Purkinje Cells/virology ; Pyramidal Cells/virology ; Recombinant Fusion Proteins/analysis ; Recombinant Fusion Proteins/biosynthesis ; Recombinant Fusion Proteins/genetics ; Tail/blood supply ; Tissue Distribution

To construct, express, purify and identify the Myc-R9-EGFP fusion protein and validate its transduction activity in the cultured porcine embryo fibroblasts. cDNA of pig c-Myc gene was amplified by RT-PCR with specific primers of 9 arginine (R9) from the primordial genital ridges and inserted into prokaryotic expression vector pET-28a-EGFP. After DNA sequencing confirmation, the recombinant plasmid was then transformed into BL21 (Escherichia coli) strain. After IPTG induction, the target fusion protein was efficiently induced to express, successfully purified by Novagen His-Bind kit, identified by SDS-PAGE and Western blotting. Finally, its high transduction activity in the porcine embryo fibroblasts was validated. The purified Myc-R9-EGFP fusion protein and the validation of its transduction activity in fibroblasts have provided an experimental foundation for further studies on the biological characterization of Myc protein, and soundly facilitated the further study of establishing pig induced pluripotent stem cells by recombinant protein.
Animals ; Arginine ; genetics ; metabolism ; Cell Line ; Cell Membrane Permeability ; drug effects ; Escherichia coli ; genetics ; metabolism ; Fibroblasts ; cytology ; metabolism ; Genetic Vectors ; genetics ; Green Fluorescent Proteins ; genetics ; metabolism ; Proto-Oncogene Proteins c-myc ; genetics ; metabolism ; Recombinant Fusion Proteins ; genetics ; metabolism ; pharmacokinetics ; Swine

OBJECTIVETo investigate the inhibitory effect of nanoparticle-mediated antisense oligodeoxynucleotide (ASODN) of human telomerase reverse transcriptase (hTERT) on telomerase in the esophageal cancer EC9706 cells.

METHODSLine-polyethylenimine (L-PEI) was used to condense ASODN into nanoparticle and to couple NGR peptides into targeting nanoparticle, and the prepared L-PEI/ASODN complexes were transfected into the EC9706 cells. Cellular uptake of L-PEI/ASODN complexes was detected by laser confocal scanning microscopy. MTT assay was used to detect the inhibitory rate of EC9706 cell growth. The level of hTERT mRNA and its protein expression were measured by RT-PCR and immunohistochemistry, respectively. Annexin V FITC/PI double labeling was used to detect cell apoptosis. The distribution of drug in nude mice was observed by laser confocal scanning microscopy, and the growth and morphology of the tumor was examined.

RESULTSThe L-PEI-mediated ASODN uptake was enhanced. After transfection, the inhibitory rate of EC9706 cells was time-dependant and there was a significant difference between control cell group and L-PEI/ASODN group (P < 0.05). At 48 h after transfection, the level of hTERT mRNA was decreased significantly compared with that of control cell group (P < 0.05), and the expression of hTERT protein was negative. There was apparent apoptosis in EC9706 cells after transfection with L-PEI/ASODN complexes. For the two NGR/L-PEI/ASODN groups, fluorescence was observed in the liver, kidney, lung and tumor tissues of nude mice, and their uptake intensity was time-dependent. The mean volume of tumors in the two NGR/L-PEI/ASODN groups was significantly smaller than those in blank control group and SODN group (P < 0.05). Apoptotic bodies were detected in the tumors of L-PEI/ASODN group.

CONCLUSIONThe NGR/L-PEI/ASODN nanoparticles can effectively reach into the human esophageal cancer xenograft and inhibit the tumor growth in nude mice, and this may provide a theoretical and experimental basis for gene therapy for human esophageal squamous cell carcinoma.

Animals ; Apoptosis ; Cell Line, Tumor ; Esophageal Neoplasms ; metabolism ; pathology ; Female ; Genetic Vectors ; Humans ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Nanoparticles ; Neoplasm Transplantation ; Oligodeoxyribonucleotides, Antisense ; genetics ; pharmacology ; Oligopeptides ; chemistry ; pharmacokinetics ; Polyethyleneimine ; chemistry ; pharmacokinetics ; RNA, Messenger ; metabolism ; Telomerase ; genetics ; metabolism ; Tissue Distribution ; Transfection ; Tumor Burden

BACKGROUNDRNA interference using short hairpin RNA (shRNA) can mediate sequence-specific inhibition of gene expression in mammalian cells. A vector-based approach for synthesizing shRNA has been developed recently. Overexpression of P-glycoprotein (P-gp), the MDR1 gene product, confers multidrug resistance (MDR) to cancer cells. In this study, we reversed MDR using shRNA expression vectors in a multidrug-resistant human breast cancer cell line (MCF-7/AdrR).

METHODSThe two shRNA expression vectors were constructed and introduced into MCF-7/AdrR cells. Expression of MDR1 mRNA was assessed by RT-PCR, and P-gp expression was determined by Western Blot and immunocytochemistry. Apoptosis and sensitization of the breast cancer cells to doxorubicin were quantified by flow cytometry and methyl thiazolyl tetrazolium (MTT) assays, respectively. Cellular daunorubicin accumulation was assayed by laser confocal scanning microscopy (LCSM). Statistical significance of differences in mean values was evaluated by Student's t tests. P < 0.05 was considered statistically significant.

RESULTSIn MCF-7/AdrA cells transfected with MDR1-A and MDR1-B shRNA expression vectors, RT-PCR showed that MDR1 mRNA expression was reduced by 40.9% (P < 0.05), 30.1% (P < 0.01) (transient transfection) and 37.6% (P < 0.05), 28.0% (P < 0.01) (stable transfection), respectively. Western Blot and immunocytochemistry showed that P-gp expression was significantly and specifically inhibited. Resistance against doxorubicin was decreased from 162-fold to 109-fold (P < 0.05), 54-fold (P < 0.01) (transient transfection) and to 108-fold (P < 0.05), 50-fold (P < 0.01) (stable transfection). Furthermore, shRNA vectors significantly enhanced the cellular daunorubicin accumulation. The combination of shRNA vectors and doxorubicin significantly induced apoptosis in MCF-7/AdrR cells.

CONCLUSIONSshRNA expression vectors effectively reduce MDR expression in a sustained fashion and can restore the sensitivity of drug-resistant cancer cells to conventional chemotherapeutic agents.

ATP-Binding Cassette, Sub-Family B, Member 1 ; analysis ; antagonists & inhibitors ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Survival ; drug effects ; Daunorubicin ; pharmacokinetics ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; Flow Cytometry ; Genes, MDR ; Genetic Vectors ; Humans ; RNA Interference ; RNA, Small Interfering ; genetics ; Transfection

This study is to report the preparation of complexes of Ad5 and anionic liposomes (AL-Ad5), the amplification of adenoviruses with enhanced green fluorescent protein (eGFP) reporter gene performed by HEK 293 cells, the adenoviral vectors purified by cesium chloride gradient centrifugation, and the titer of adenovirus determined by cytopathic effect (CPE) method, hexon capsid immunoassay and quantitative-PCR (Q-PCR), separately. The prescription and experiment conditions were optimized by central composite design (CCD). The complexes of Ad5 and AL-Ad5 were formulated by the calcium-induced phase change method. The morpholopy, particle size and zeta potential were detected by dynamic light scattering (DLS) and transmission electron microscopy (TEM), respectively. Additionally, the bicolourable fluoresce-labeled complexes (F(labeled)-AL-Ad5) were prepared and their intracellular location in MDCK cells was detected by confocal laser scanning microscopy (CLSM). The results indicate that the complexes of AL-Ad5 exhibited a uniform distribution with a particle size of 211 +/- 10 nm and a zeta potential of -41.2 +/- 2.2 mV. The result of CLSM demonstrates that the intracellular location of red fluoresce-labeled adenovirus was consistent with that of green fluoresce-labeled liposomes suggesting that the naked adenovirus was well encapsulated by the anionic liposomes in complexes of AL-Ad5.
Adenoviridae ; genetics ; ultrastructure ; Animals ; Anions ; Cytopathogenic Effect, Viral ; Dogs ; Drug Compounding ; methods ; Genetic Vectors ; Green Fluorescent Proteins ; chemistry ; HEK293 Cells ; Humans ; Liposomes ; chemistry ; pharmacokinetics ; ultrastructure ; Madin Darby Canine Kidney Cells ; Microscopy, Confocal ; Microscopy, Electron, Transmission ; Particle Size ; Polymerase Chain Reaction ; methods ; Recombinant Fusion Proteins ; ultrastructure