To prepare AS1411 targeted nano-ultrasonic contrast agent with liquid core, and to evaluate its ability for ultrasonic contrast enhancement and targeting MCF-7 cell in vitro.
 Methods: The modified solvent evaporation, self-synthesized membrane material and perfluorobrominane (PFOB) was used to form nano-ultrasonic contrast agent with PFOB core (nanoparticles, NP); then N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide (EDC/NHS) catalysis was used to connect AS1411 to the surface of NP to prepare NP-AS1411. The transmission electron microscopy was chosen to check the morphology of NP-AS1411. The size, surface charge, encapsulation efficiency, biocompatibility, the contrast grey value and the stability of NP-AS1411 and NP were compared. Whether AS411 was attached to the surface of NP was checked by gel electrophoresis. Fluorescence microscopy and flow cytometry were performed to examine the targeting ability of AS1411.
 Results: NP-AS1411 was a shell-nuclear structure under the electron microscope. Its size was at (245.4±16.5) nm, which was larger than that of NP (P=0.05). There was no significant difference in surface charge and encapsulation efficiency between NP-AS1411 and NP (P>0.05). In the MTT experiment, the cell viability decreased significantly at high concentration of NP-AS411 (25 mg/mL) after incubation for 24 h compared with the control group (0 mg/mL ) (P<0.05). The contrast gray value of NP-AS1411 was at 86.1+ 6.7, which was significantly higher than that of deionized water (P<0.05), and equivalent to that of NP (P>0.05). The contrast grey value of AS1411-NP was 80.1±9.2 after keeping at room temperature for 24 h, which showed no obviously change comparing with that before the treatment (P>0.05). The size of NP-AS1411didn't change too (P>0.05). The results of gel electrophoresis demonstrated that the AS1411 connecting to the surface of NP was the most when the molar ratio of NP:AS1411 was at 40:1. Flow cytometry analysis confirmed that NP and NP-AS1411 were combined with MCF-7 cells separately but the fluorescence produced by the combination of NP-AS1411 and MCF-7 was more intense.
 Conclusion: The modified solvent evaporation and EDC/NHS catalysis could successfully prepare ultrasound contrast agents with aptamer-conjugated nanoparticles with liquid core. The targeted ultrasonic contrast agents with liquid core possess good ultrasonic contrast enhancement ability in vitro, stability and specificity as well.
Cell Survival ; Contrast Media ; chemical synthesis ; Fluorocarbons ; Humans ; MCF-7 Cells ; Microscopy, Electron, Scanning Transmission ; Nanoparticles ; chemistry ; ultrastructure ; Oligodeoxyribonucleotides ; chemical synthesis

The present paper is aimed to detect superparamagnetic iron oxide labeled c-erbB2 oncogene antisense oligonucleotide probe (magnetic antisense probe) connected with SK-Br-3 oncocyte mRNA nucleotide by high resolution atomic force microscope (AFM). We transfected SK-Br-3 oncocyte with magnetic antisense probe, then observed the cells by AFM with high resolution and detected protein expression and magnetic resonance imagine (MRI). The high resolution AFM clearly showed the connection of the oligonucleotide remote end of magnetic antisense probe with the mRNA nucleotide of oncocyte. The expression of e-erbB2 protein in SK-Br3 cells were highly inhibited by using magnetic antisense probe. We then obtained the lowest signal to noise ratio (SNR) of SK-Br-3 oncocyte transfected with magnetic antisense probe by MRI (P<0.05). These experiments demonstrated that the high resolution AFM could be used to show the binding of magnetic antisense probe and SK-Br-3 mRNA of tumor cell nuclear.
Breast Neoplasms ; metabolism ; pathology ; Cell Line, Tumor ; DNA, Antisense ; chemistry ; genetics ; Female ; Ferric Compounds ; chemistry ; Genes, erbB-2 ; genetics ; Humans ; Magnetics ; Microscopy, Atomic Force ; methods ; Molecular Probe Techniques ; Nucleic Acid Probes ; chemistry ; genetics ; Oligodeoxyribonucleotides ; chemistry ; genetics ; Oxyphil Cells ; ultrastructure ; RNA, Messenger ; genetics ; metabolism

CpG-Oligodeoxynucleotide (ODN) has two backbones. Phosphorothioate backbone (PS) shows a strong immunostimulating effect while phosphodiester (PE) shows little in vivo. 3' hexameric deoxyriboguanosine-run (3' dG6-run) conjugation to PE CpG-ODN has been reported to enhance immunostimulation and to protect against asthma when injected at the time of sensitization in mice. We evaluated the treatment effects of PE and PS CpG-ODN with or without 3' dG6-run on asthma in presensitized mice. BALB/c mice sensitized with ovalbumin and alum were challenged with 1% ovalbumin on three days. CpG-ODNs (100 microgram) or PBS were injected 4 times; 27 hr before challenge and 3 hr before each challenge (CpG-dG6: CpG-ODN with 3' dG6-run, PE*-CpG-dG6: PE-CpG-dG6 with two PS backbones at the 5' terminus). PE-CpG showed no treatment effect. PE-CpG-dG6 only increased ovalbumin-specific IgG2a. PE*-CpG-dG6 increased ovalbumin-specific IgG2a but also reduced BAL fluid eosinophils and airway hyperresponsiveness. PS-CpG increased ovalbumin-specific IgG2a, reduced airway inflammation and airway hyperresponsiveness. PS-CpG-dG6 was less effective than PS-CpG on airway inflammation and airway hyperresponsiveness. In pre-sensitized mice, PE-CpG required not only 3' dG6-run but also the modification of two PS linkages at 5' terminus to inhibit features of asthma. PS-CpG was strong enough to inhibit asthma but PS-CpG-dG6 was less effective.
Animals ; Anti-Asthmatic Agents/*therapeutic use ; Asthma/*drug therapy/physiopathology ; Bronchial Hyperreactivity/drug therapy ; Bronchoalveolar Lavage Fluid/immunology ; Deoxyguanosine/*analogs & derivatives/*chemistry ; Female ; Immunoglobulin G/metabolism ; Interleukin-12/analysis ; Interleukin-4/analysis ; Interleukin-5/analysis ; Lung/pathology ; Mice ; Mice, Inbred BALB C ; Oligodeoxyribonucleotides/*therapeutic use ; Phosphorothioate Oligonucleotides/therapeutic use ; Splenomegaly/pathology

The aim of the paper is to prepare stable antisense oligodeoxynucleotides-loaded cationic liposomes and evaluate the transfection efficiency of asODN to MCF-7 oophoroma cells and study their distribution to different tissues in mice. Antisense oligodeoxynucleotides (asODN)-loaded cationic liposomes were prepared by a thin film-adsorption-lyophilization method which is simple and can overcome crucial pharmaceutical defects (e.g. instability) of liposomes during storage. The morphology was investigated by transmission electron microscope. The size and surface charge of the liposomes were determined by laser particle analyter. The dissociated ligodeoxynucleotides were separated from the liposomes by sephadex column and the entrapment efficiency was determined by using an ultraviolet photometer. Trehalose, mannitol, and glycine were suitable for lyophilization especially trehalose. The resulting liposomes were global microcapsule in a narrow particle size with a mean diameter of 175 nm and 320 nm before and after lyophilization, and a high zeta potentials of +32 mV. The dissociated asODN were separated from the liposomes by sephadex G-50 column and the entrapment coefficient of asODN was 88.4% pre and 83.2% post-lyophilization separately for trehalose. The growth of MCF-7 oophoroma cells were inhibited in vitro obviously (P < 0.05) and transfection efficiency of asODN was 18%, 26%, 44% after 2 h, 4 h and 8 h, respectively. The formulation and method can be used to prepare stable cationic liposomes which can effectively inhibit the growth of MCF-7 oophoroma cells and obtain a high transfection efficiency. This system can improve distribution amount of asODN to tissues especially tumors in mice.
Animals ; Breast Neoplasms ; metabolism ; pathology ; Cations ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Drug Carriers ; Female ; Freeze Drying ; Humans ; Liposomes ; chemistry ; pharmacokinetics ; pharmacology ; Mice ; Mice, Inbred BALB C ; Neoplasm Transplantation ; Oligodeoxyribonucleotides, Antisense ; chemistry ; genetics ; Particle Size ; Transfection

External Guide Sequences (EGSs) represents a novel nucleic acid based gene interference approach to modulate gene expression. They are oligonucleotides that consist of a sequence complementary to a target mRNA and recruit intracellular RNase P for specific degradation of the target RNA. DNA-based EGS1386 with a size of 12 nt was chemically synthesized to target the mRNA coding for the UL49 gene of human cytomegalovirus (HCMV). The DNA-based EGS1386 molecule efficiently directed human RNase P to cleave the target mRNA sequence in vitro. A reduction of more than 50% in the levels of UL49 expression was observed in human cells treated with the DNA-based EGS1386 targeted UL49 assayed by fluorescent quantization PCR and Western blotting. This results showed that the DNA-EGS1386 can effectively guide the RNase P cut the target mRNA. Therefore, DNA-EGS can develop into a new gene silencing technology and potential of the anti-viral reagents.
Base Sequence ; Cytomegalovirus ; drug effects ; genetics ; metabolism ; Cytomegalovirus Infections ; enzymology ; virology ; DNA, Viral ; genetics ; Directed Molecular Evolution ; methods ; Gene Expression Regulation, Viral ; Humans ; Nucleic Acid Conformation ; Oligodeoxyribonucleotides ; genetics ; pharmacology ; RNA, Guide ; chemistry ; pharmacology ; RNA, Messenger ; genetics ; metabolism ; Ribonuclease P ; genetics ; metabolism ; Viral Structural Proteins ; genetics ; metabolism

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

To develop a method for the detection of surface-confined peptides containing cysteine residues or oligodeoxynucleotides (ODNs) whose 3' ends modified with thiol groups, and a thiol-specific fluorescent cross-linker, N-(9-acridinyl) maleimide (NAM) was used. The peptides studied herein include both the oxidized and reduced forms of glutathione, and a hexapeptide (FT). Peptides are first attached onto the activated 11-mercaptoundecanoic acid (MUA)-terminated alkanethiol self-assembled monolayers (SAMs) and then derivatized with NAM. The cysteine residues was determined by using electrochemical desorption and fluorescence detection. GSH concentration as low as 40 pmol x L(-1) can be measured. The fluorescence intensity in the case of FT is about 3 times as high as that for GSH, which is consistent with the molar ratio of cysteine residues in these two molecules. The analytical performance of gene analysis was also evaluated through the analyses of a complementary target and targets with varying numbers of mismatching bases. The method described here is simple, sensitive, reproducible, and does not require sophisticated analytical instrumentation and separation procedures.
Biosensing Techniques ; methods ; Cysteine ; analysis ; Electrochemistry ; methods ; Fluorescence ; Glutathione ; analysis ; chemistry ; Maleimides ; chemistry ; Oligodeoxyribonucleotides ; analysis ; Reproducibility of Results ; Sensitivity and Specificity

OBJECTIVETo prepare the superparamagnetic iron oxide (SPIO)-labeled antisense oligodeoxynucleotide (ASODN) probe and evaluate the application of this probe in cellular magnetic resonance imaging (MRI).

METHODSWe prepared the SPIO-labeled ASODN probe using chemical cross linking method to conjugate SPIO to ASODN, detected its configuration by atomic force microscopy, determined the conjugating rate and biology activation by high performance liquid chromatography, and detected the stability by polyacrylamide gel electrophoresis. After that, we transfected the SK-Br3 oncocytes which had over-expression of the c-erbB2 oncogene by this probes, observed the intracellular iron distribution by optical microscope, measured iron content by atomic absorption spectroscopy, and observed the signal change by MRI.

RESULTSAtomic force microscope showed that the SPIO-labeled ASODN probe was mostly spherical and well-distributed, with a diameter of 25-40 nm and a conjugating rate of 100%. This probe had inhered biological activity and stability. In addition, light microscopy revealed an intracellular uptake of iron oxides in the transfected SK-Br3 oncocyte, and the iron content of the group of transfected SK-Br3 oncocytes was significantly higher than those of other contrast groups (all P < 0.01). MRI showed that transfected SK-Br3 oncocyte had the lowest signal among all other cells (all P < 0.05).

CONCLUSIONSWe prepared the SPIO-labeled ASODN probe successfully. It can effectively transfect SK-Br3 oncocyte and enter SK-Br3 oncocyte, and thus reduce the signal intension in MRI.

Cell Line, Tumor ; DNA, Antisense ; chemistry ; genetics ; Ferric Compounds ; chemistry ; Humans ; Magnetic Resonance Imaging ; Magnetics ; Molecular Probe Techniques ; Oligodeoxyribonucleotides ; chemistry ; genetics ; Oxyphil Cells ; chemistry ; Receptor, ErbB-2 ; analysis ; genetics

OBJECTIVETo study the regulating effects of a novel CpG oligodeoxynuleotide and the synergistic effect of chitosan-nanoparticles (CNP) with CpG on immune responses of mice, which were used to develop a novel immunoadjuvant to boost immune response to conventional vaccines.

METHODSA novel CpG ODN containing 11 CpG motifs was synthesized and its bioactivities to stimulate the proliferation of lymphocytes of pig in vitro were detected. Then it was entrapped with CNP prepared in our laboratory by the method of ionic cross linkage, and immunized Kunming mice were co-inoculated with paratyphoid vaccine. The peripheral blood was collected weekly from the tail vein of inoculated mice to detect the contents of IgG, IgA, IgM, and specific antibody against salmonella as well as the levels of interleukin-2 (IL2), IL-4, and IL-6 by SABC-ELISA assay. The numbers of leucocytes, monocytes, granuloytes, and lymphocytes were calculated separately using the routine method. The experimental mice were orally challenged with virulent salmonella 35 days after inoculation.

RESULTSThis CpG ODN could remarkably provoke the proliferation of lymphocytes of pig in vitro in contrast with the control (P < 0.05). Compared with those of the control, immunoglobulins, including IgG, IgA, IgM, and specific antibodies to paratyphoid vaccine, increased significantly in sera from the CpG or CpG-CNP-vaccinated mice (P < 0.05). IL-2, IL-4, and IL-6 increased remarkably in sera from immunized mice (P < 0.05). The leucocytes, monocytes, granuloytes, and lymphocytes of the mice immunized with CpG or CpG-CNP were also increased in number (P < 0.05). After the challenge, these immunity values were elevated in the mice vaccinated with CpG or CpG-CNP. The immunized mice all survived, while the control mice fell ill with evident lesions with diffuse hemorrhage in stomach, small intestine, and peritoneum.

CONCLUSIONSCpG ODN entrapped with CNP is a promising effective immunoadjuvant for vaccination, which promotes humoral and cellular immune responses, enhances immunity and resistance against salmonella by co-administration with paratyphoid vaccine.

Adjuvants, Immunologic ; administration & dosage ; pharmacology ; Animals ; Antibodies, Bacterial ; blood ; Cell Proliferation ; Chitosan ; chemistry ; Drug Therapy, Combination ; Enzyme-Linked Immunosorbent Assay ; Immunoglobulin Isotypes ; blood ; Interleukins ; blood ; Lymphocyte Activation ; drug effects ; Lymphocytes ; cytology ; Mice ; Nanoparticles ; chemistry ; Oligodeoxyribonucleotides ; administration & dosage ; pharmacology ; Paratyphoid Fever ; immunology ; prevention & control ; Salmonella ; physiology ; Salmonella Infections, Animal ; immunology ; prevention & control ; Swine ; immunology ; Typhoid-Paratyphoid Vaccines ; immunology

AIMTo investigate the effect of nanoparticles for antisense oligodeoxynucleotide (ASODN) of hTERT mRNA on A549 cells.

METHODSThe cationic polybutylcyanoacrylate nanoparticles (NPs) were prepared by an emulsion polymerization process in the presence of DEAE-dextran. Antisense oligodeoxynucleotides were loaded on the particles by adsorption. The cytotoxicity of NPs and proliferation of A549 cells were detected by MTT assay. Intracellular fluorescence intensity after transfecting the 5'-FITC-labelled ASODN (FASODN) and cell cycles were determined by flow cytometry (FCM). Inverse microscope was used to observe the modality of A549 cell transfected by NPs for ASODN. The protein expression of hTERT was measured by immunocytochemistry.

RESULTSThe cytotoxicity increased evidently with the increasing concentration of NPs over 2.5 g x L(-1). The intracellular fluorescence in FASODN-NP group was obviously stronger than that in FASODN group (NPs free) after transfection for 24 h (P < 0.01). The inhibitory rate for cell modality change and proliferation after the treatment with ASODN-NP at 72 h reached peak , 62.4% , 44.6% and 36.4% for ASODN1-NP group, ASODN2-NP group and ASODN3-NP group, respectively; The cell cycle in ASODN-NP group varied observably compared with control group and sense oligodeoxynucleotide-nanoparticle (SODN-NP) group and the cell cycle was blocked in G1 phase, the cell number in S phase decreased obviously (P < 0.01); The hTERT protein expression of ASODN-NP group reduced clearly.

CONCLUSIONASODN-NP of hTERT can inhibit the proliferation of A549 cells effectively and cause the change of cell cycle, restraint of protein expression of hTERT and cell viability.

Adenocarcinoma ; enzymology ; pathology ; Cell Cycle ; drug effects ; Cell Death ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Enbucrilate ; chemistry ; Humans ; Lung Neoplasms ; enzymology ; pathology ; Nanoparticles ; Oligodeoxyribonucleotides, Antisense ; genetics ; pharmacology ; RNA, Messenger ; genetics ; metabolism ; Telomerase ; genetics ; metabolism ; Transfection