OBJECTIVETo investigate the specificity of the dual-functionalized nanoparticles probes (NPs) self-assembled with colloidal gold.

METHODS13-nm gold nanoparticles were prepared with citrate reduction of HAuCl(4). These gold nanoparticles were sequentially functionalized with the specific single-strand oligonucleotide of HA gene of influenza A virus (H1N1) and disulfide molecules of m/z at 693. The NPs solution showed the red formation. The magnetic microparticles (MPs) were modified with another specific single-strand oligonucleotide in HA gene of H1N1. The sandwich complexes (MP-Target-NPs) were formed by the target DNA with the MPs and the NPs. The color change in the solution was observed and the dehybridization product was detected by MALDI TOF MS. Moreover specificity of the probes was investigated with nano-water (as a blank control) and the different target DNAs including complementary DNA,non-complementary DNA and two DNAs of one base mismatch, respectively.

RESULTThe red formation and the positive signal in MS detection of reporter mass code 693 ([M+Na](+)) were observed,which indicated the formation of sandwich complexes formed only when the completely complementary target DNAs were presented in the solution. No color formation changes and no peak signal detected by MALDI TOF MS were observed,showing that none of target of interest (nano-pure water),non-complementary DNA and two DNAs of one base mismatch existed in the systems,which indicated no sandwich complexes formed between the target DNAs and the two probes.

CONCLUSIONConsidering the simple preparation procedure and high specificity,the dual-functionalized gold nanoparticle probes would be widely and increasingly used in nucleic acid analysis. In particular,it would have broad application prospects in early diagnosis of diseases,single nucleotide polymorphism (SNP) typing and so on.

DNA Probes ; chemistry ; Gold Colloid ; chemistry ; Influenza A Virus, H1N1 Subtype ; genetics ; Metal Nanoparticles ; chemistry ; Oligonucleotides ; genetics ; Sensitivity and Specificity

OBJECTIVETo determine whether 3'phosphorothioate-modified-2 terminal mismatched primers can turn off DNA polymerization mediated by Exo(+) polymerase.

METHODSTwo-directional primer extension was performed using polymerase with and without 3' exonuclease activity. The effects of unmodified primers and 3' phosphorothioate-modified primers on primer extension were evaluated.

RESULTSExo(-) polymerase yielded products from matched and mismatched primers regardless of their modification. However, 3' phosphorothioate-modified primers with a single base mismatch at -2 position worked similarly to the terminal (-1) mismatched primers in triggering the novelly reported "off-switch" of Exo(+) polymerase.

CONCLUSIONThese data suggested that the "off-switch" can be of enormous application in the diagnosis of single gene diseases and in the association studies by single nucleotide polymorphism screening.

DNA Primers ; chemistry ; genetics ; Exonucleases ; metabolism ; Humans ; Phosphorothioate Oligonucleotides ; chemistry ; genetics ; Polymerase Chain Reaction ; Polymorphism, Single Nucleotide

In order to obtain nucleotides aptamers bind to IgE, 80 bp nucleotides single-stranded DNA library containing 40 random nucleotides was designed and synthesized. Oligonucleotides that bind to human Cepsilon3-Cepsilon4 protein were isolated from ssDNA pools by the systematic evolution of ligands by exponential enrichment (SELEX) method using nitrocellulose filters as screening medium. Through the optimization of critical PCR and asymmetric PCR parameters including annealing temperature, cycles, and molar ratios of target protein and ssDNA etc, a suitable screening system was established. The aptamers of Cepsilon3-Cepsilon4 protein with high affinity and high specificity were identified by ELISA with biotin-streptavidin-horseradish peroxidase system, and its primary sequence and second structure were analyzed by DNAMAN package and DNA folding sever after being cloned and sequenced. Moreover, target protein was bound to one aptamer and another aptamer modified with biotion together forming a sandwich-like complex, which was captured in microwell to detect IgE concentration using the optimal combination in the sandwich method named enzyme-linked aptamers sorption assay (ELASA). The method could be used for the quantitative detection of human IgE, and whose sensitivity reached to 120 ng x mL(-1).
Aptamers, Nucleotide ; chemistry ; genetics ; isolation & purification ; Base Sequence ; DNA, Single-Stranded ; chemistry ; Humans ; Immunoglobulin epsilon-Chains ; chemistry ; genetics ; Oligonucleotides ; chemistry ; SELEX Aptamer Technique ; methods ; Sensitivity and Specificity

OBJECTIVE: To study the safety and efficiency of the transfection of antisense oligonucletide into kidney mediated by lipid microbubbles, and to evaluate its potential clinical application. METHODS: The potential and conditions regarding the transfection self-made lipid microbubbles (CY5)-labeled-oligonucleotide (ODN) or CY5-labeled-ODN connective tissue growth factor (CTGF) into the rat kidney were evaluated. Th e safety was evaluated by HE staining, liver and renal function tests. The transfection efficiency was evaluated by fluorescence microscopy. Th e expression of CTGF was detected by RT-PCR and Western blot. RESULTS: Self-made lipid microbubble and/or ultrasound significantly enhanced the efficiency of gene transfer and expression in the kidney. Especially, 85%-90% of total glomerular could be transfected. CY5-labeled-ODN expression could be observed in glomerular, tubular and interstitial area. Th ere was no significant change in blood tests aft er gene transfer. Levels of LDH in 7 days were decreased compared with that at the fi rst day aft er the transfection (P<0.05). CTGF expression was successfully suppressed by transfection of CTGF-antisense-ODN into kidney. CONCLUSION The ultrasound-mediated gene transfer by self-made lipid microbubble could enhance the efficiency of ODN and expression in the rat kidney. Th is self-made lipid microbubbles supplement may be use for transfection of target genes.
Animals ; Connective Tissue Growth Factor ; genetics ; metabolism ; Kidney ; metabolism ; Lipids ; chemistry ; Microbubbles ; Oligonucleotides, Antisense ; genetics ; RNA, Messenger ; Rats ; Transfection ; Ultrasonics

Peptide nucleic acid (PNA) is a DNA surrogate in which the phosphate deoxyribose backbone of DNA is replaced by repeating N-(2-aminoethyl)glycine units. PNA can hybridize to the complementary DNA and RNA with higher affinity than their oligonucleotide counterparts. This character of PNA not only makes it a new tool for the studies of molecular biology but also the potential candidate for gene-targeting drugs. The non-ionic backbone of PNA leads to stable hybrids with the nucleic acids, but at the same time, the neutral backbone results in poor cellular uptake. To address this problem, studies on modified PNA progress rapidly in recent years. We reviewed literature reports combined with our study about the delivery methods, including backbone modified PNA and PNA-ligand conjugates, and the cellular uptake of modified PNA. In addition, we summarized the problems and future prospect of the cellular delivery of modified PNA.
DNA, Complementary ; Drug Delivery Systems ; Glycine ; analogs & derivatives ; Humans ; Nucleic Acid Hybridization ; Oligonucleotides ; Peptide Nucleic Acids ; chemistry ; RNA

In this paper, the situation on antisense oligonucleotide as a means of gene therapy was outlined, and the main factors impeding its progress at present was summarized. The one of main factors is the efficiency of antisense oligonucleotide as a drug and the other is the side-effect in clinical use. At the level of cell and gene, these influential factors were analyzed in detail. The main factor that makes side-effect in using antisense oligonucleotide is the difficulty to distinguish effectively homologous-gene from target gene. The another factor is the secondary structure and three-dimensional structure of target gene that seriously affect antisense oligonucleotide to arrive at target position. The third problem is what can affect antisense oligonucleotide transmission and quick annealing. How use computer technique to analyze fully the target gene of antisense oligonucleotide including the secondary structure and homology of target gene, and to design effective antisense oligonucleotide, in order to reduce its side-effect in clinical use of antisense oligonucleotide as a drug of gene therapy, and the computer-aid design method were described.
Computer-Aided Design ; Fusion Proteins, bcr-abl ; genetics ; Genetic Therapy ; Humans ; Nucleic Acid Conformation ; Oligonucleotides, Antisense ; therapeutic use ; RNA ; chemistry

The aim of this study is to explore the optimal labeling condition of technetium-99m labeled antisense oligonucleotides (ASON) DNA and sense oligonueleotides (SON) DNA against multi-drug resistance gene-1 (MIDR1) mRNA, to prepare its two-step icefrozen kits, and to perform the quality control of technetium-99m labeled ASON and SON DNAs and its two-step icefrozen kits. A 20 mer single-stranded ASON sequence and its SON sequence against MDR1 mRNA were synthesized respectively, both of the ASON and SON DNAs were uniform phosphorothioated for this investigation with a primary amine on the 5'-end via a six-carbon alkyl linker, and then were labeled with technetium-99m by conjugating with the bifunctional chelator S-Acetyl NHS-MAG3 to form ASON- and SON-MAC3 DNAs. The optimal labeling condition was explored by varying the amount of ASON- and SON-MAG3 DNAs, SnCl2.2H2O and buffer, the pH value in the reaction medium was also adjusted. The technetium-99m labeled ASON and SON DNAs' two-step icefrozen kits were developed. The radiochemical purities, labeling stability of ASON- and SON-MAG3 DNAs in vivo and vitro were measured, and stability of the two-step icefrozen kits were also studied. The recycled rates of ASON- and SON-MAG3 DNAs were over 70% (n >6), the two-step icefrozen kits of ASON- and SON-MAG3 DNAs were colourless ice crystal. The radiochemical purities of technetium-99m labeled ASON- and SON-MAG3 DNAs were over 92 %. The radiochemical purities were over 90% after stored at room temperature for 24 hours. The kits were stable within 6 months when stored at 0 degrees C, the radiochemical purities of technetium-99m labeled ASON- and SON-MAG3 DNAs were still over 90%. The two-step icefrozen kits of ASON- and SON-MAG3 DNAs were successfully developed. The radiochemical purities were all over 90%. The labeling method was simple, feasible and efficient with good stability.
Animals ; DNA, Antisense ; chemistry ; Isotope Labeling ; methods ; Mice ; Mice, Nude ; Multidrug Resistance-Associated Proteins ; chemistry ; pharmacokinetics ; Oligonucleotides, Antisense ; chemistry ; pharmacokinetics ; Radiopharmaceuticals ; chemical synthesis ; pharmacokinetics ; Random Allocation ; Technetium Tc 99m Mertiatide ; chemistry ; pharmacokinetics

The study was designed to investigate annexin II resulting in molecular pathological mechanism of the primary fibrinolysis and establish annexin II vector model for further research on disturbance of coagulation. A target gene was amplified from human umbilical vein endothelial cells (HUVEC) by RT-PCR. Annexin II gene fragment was purified and ligated with molecular biological recombinant technology. The recombinant of plasmid annexin II was transfected into HL-60 cells and its distribution in the cell and structure characteristics of annexin II protein were evaluated by multi-photon excitation laser scanning microscope. By means of flow cytometry (FCM) and Werstern blot technique, the protein expression was qualitatively and quantitatively analyzed. Transfected cells were treated in vitro with annexin II antisense oligonucleotide (AS) targeting to the start site of annexin II cDNA. The results showed that the recombinant pZeoSV2(+)/ANN II was constructed successfully and expressed in HL-60 cells. The protein expression was distributed on the surface of cell by fluorescence assay. After transfection for 48 hours, the cells occurred higher level of expression. The level of the plasmin was significantly enhanced in the present of annexin II. The FCM and Western blot analysis showed the annexin II expression was similar both in transiently and stably transfected in HL-60 cells. Annexin II antisense oligonucletide and McAb significantly inhibited the activity of plasminogen. It was concluded that annexin II plays an important role in the fibrinotysis. Annexin II vector was defined as a expression tool for further studying fibrinolysis and coagulopathy in malignant disease.
Annexin A2 ; genetics ; physiology ; Endothelium, Vascular ; chemistry ; cytology ; Fibrinolysis ; Genetic Vectors ; HL-60 Cells ; Humans ; Oligonucleotides, Antisense ; pharmacology ; Polymerase Chain Reaction ; Recombinant Proteins ; biosynthesis

OBJECTIVETo establish a single-cell whole genome amplification (WGA) technique, in combination with comparative genomic hybridization (CGH), for analyzing chromosomal copy number changes, and to explore its clinical application in preimplantation genetic diagnosis (PGD).

METHODSTwelve single-cell samples with known karyotypes, including 5 chorionic villus samples, 4 human embryonic stem cell (hESC) samples and 3 peripheral lymphocyte samples, and 4 single blastomere samples carrying chromosomal abnormalities detected by PGD, were collected for whole genome amplification by combining primer extension preamplification (PEP) with degenerate oligonucleotide primed-PCR (DOP-PCR) amplification. The amplified products labeled by red fluorescence were mixed with control DNA labeled by green fluorescence, and then the mixture was analyzed by CGH. As a comparison, 10 single cell samples were amplified by DOP-PCR only and then CGH analysis was performed.

RESULTSThe amplification using PEP-DOP-PCR was more stable than traditional DOP-PCR. The products of PEP-DOP-PCR range from 100 bp to 1000 bp, with the mean size being about 400 bp. The CGH results were consistent with analyses by other methods. However, only 6 out of 10 single cell samples were successfully amplified by DOP-PCR, and CGH analysis showed a high background and 2 samples showed inconsistent results from other methods.

CONCLUSIONPEP-DOP-PCR can effectively amplify the whole genome DNA of single cell. Combined with CGH, this WGA method can successfully detect single-cell chromosomal copy number changes, while DOP-PCR was easy to fail to amplify and amplify inhomogeneously, and CGH analysis using this PCR product usually showed high background. These results suggest that PEP-DOP-CGH is a promising method for preimplantation genetic diagnosis.

Comparative Genomic Hybridization ; methods ; DNA Primers ; Genetic Testing ; methods ; Humans ; Karyotyping ; methods ; Nucleic Acid Amplification Techniques ; methods ; Nucleic Acid Hybridization ; methods ; Oligonucleotides ; chemistry ; Preimplantation Diagnosis ; methods

AIMTo investigate the possibility of polymethacrylate nanoparticles (NP) for antisense oligodeoxynucleotides delivery system.

METHODSThe nanoparticles were prepared by evaporating ethenol solution containing Eudragit RL100 or RS100, and then mixtured with oligonucleotides. The morphology and size were investigated by a transmission electron microscope and Mastersizer particle characterization systems, and the cytotoxicity was evaluated by Trypan Blue staining and hemolysis test. The flow cytometer was used to determine the uptake of fluorescence-labelled oligodeoxynucleotides.

RESULTSThe morphology of nanoparticles showed spherical and orderly, the average diameter was about 127 nm, and almost the antisense oligodeoxynucleotides (ODN) were loaded when NP: ODN was 6.6. The uptake of ODN was significantly increased when loaded by nanoparticles, which well depended on the nanoparticles concentration. Meanwhile, slightly cytotoxicity was observed when high dose of nanoparticles was used.

CONCLUSIONThe polymethacrylate nanoparticles appeared to be a promising vehicle for gene delivery.

Acrylic Resins ; chemistry ; toxicity ; Animals ; Drug Carriers ; Drug Delivery Systems ; Hemolysis ; drug effects ; Nanotechnology ; Oligonucleotides, Antisense ; administration & dosage ; Particle Size ; Technology, Pharmaceutical ; methods