- Development of a DNA-liposome complex for gene delivery applications. [Journal Article]
- MSMater Sci Eng C Mater Biol Appl 2017 Jun 01; 75:191-197
- The association structures formed by cationic liposomes and DNA (Deoxyribonucleic acid)-liposome have been effectively utilized as gene carriers in transfection assays. In this research study, cation...
The association structures formed by cationic liposomes and DNA (Deoxyribonucleic acid)-liposome have been effectively utilized as gene carriers in transfection assays. In this research study, cationic liposomes were prepared using a modified lipid film hydration method consisting of a lyophilization step for gene delivery applications. The obtained results demonstrated that the mean particle size had no significant change while the polydispersity (PDI) increased after lyophilization. The mean particle size slightly reduced after lyophilization (520±12nm to 464±25nm) while the PDI increased after lyophilization (0.094±0.017 to 0.220±0.004). In addition. The mean particle size of vesicles increases when DNA is incorporated to the liposomes (673±27nm). According to the Scanning Electron Microscopy (SEM) and transmission electron microscopy (TEM) images, the spherical shape of liposomes confirmed their successful preservation and reconstitution from the powder. It was found that liposomal formulation has enhanced transfection considerably compared to the naked DNA as negative control. Finally, liposomal formulation in this research had a better function than Lipofectamine® 2000 as a commercialized product because the cellular activity (cellular protein) was higher in the prepared lipoplex than Lipofectamine® 2000.
- Determination of the Biological Form of Human Cytomegalovirus DNA in the Plasma of Solid-Organ Transplant Recipients. [Journal Article]
- JIJ Infect Dis 2017 Apr 12
- CONCLUSIONS: Cytomegalovirus DNA in SOTR plasma is almost exclusively free DNA, highly fragmented, and not virion associated.
- Taxonomic divergence of the green naked-stipe members of the genus Microglossum (Helotiales). [Journal Article]
- MMycologia 2017; 109(1):46-54
- Four new species of the Ascomycete genus Microglossum are recognized, based on morphological characters and DNA sequences of nuc rDNA (ITS region and 28S gene) and the second largest subunit of RNA p...
Four new species of the Ascomycete genus Microglossum are recognized, based on morphological characters and DNA sequences of nuc rDNA (ITS region and 28S gene) and the second largest subunit of RNA polymerase II (RPB2). They differ from Microglossum nudipes by the color of the ascocarps and the sizes and shapes of ascospores, asci, and paraphyses. A lectotype is proposed, and an emended description is provided for M. nudipes. Descriptions of new species Microglossum clavatum, M. truncatum, M. pretense, and M. tenebrosum are provided. Other closely related species in the group of green earth tongues include Microglossum viride, M. rickii, and M. griseoviride. An identification key to green Microglossum species is presented.
- A pH-responsive colorimetric strategy for DNA detection by acetylcholinesterase catalyzed hydrolysis and cascade amplification. [Journal Article]
- BBBiosens Bioelectron 2017 Aug 15; 94:651-656
- A pH-responsive colorimetric strategy was designed for sensitive and convenient biosensing by introducing acetylcholinesterase (AChE) catalyzed hydrolysis of acetylcholine to change solution pH and p...
A pH-responsive colorimetric strategy was designed for sensitive and convenient biosensing by introducing acetylcholinesterase (AChE) catalyzed hydrolysis of acetylcholine to change solution pH and phenol red as an indicator. Using DNA as a target model, this technique was successfully employed for sensitive DNA analysis by labeling AChE to DNA. The sensitivity could be greatly improved by coupling a newly designed magnetic probe with target DNA-triggered nonenzymatic cascade amplification. In the presence of a help DNA (H) and the functional probe, the cascade assembly via toehold-mediated strand displacement released the AChE-conjugated sequence from magnetic beads, which could be simply separated from the reaction mixture to catalyze the hydrolysis of ACh in detection solution. The color change of detection solution from pink to orange-red, orange-yellow and ultimately yellow could be used for target DNA detection by naked eye and colorimetry with the absorbance ratio of detection solution at 558nm to 432nm as the signal. The nonenzymatically sensitized colorimetric strategy showed a linear range from 50pM to 50nM with a detection limit of 38pM, indicating a promising application in DNA analysis.
- Bioresponsive Release System for Visual Fluorescence Detection of Carcinoembryonic Antigen from Mesoporous Silica Nanocontainers Mediated Optical Color on Quantum Dot-Enzyme-Impregnated Paper. [Journal Article]
- ACAnal Chem 2017 Apr 12
- An all-in-one paper-based analytical device (PAD) was successfully developed for visual fluorescence detection of carcinoembryonic antigen (CEA) on CdTe/CdSe quantum dot (QD)-enzyme-impregnated paper...
An all-in-one paper-based analytical device (PAD) was successfully developed for visual fluorescence detection of carcinoembryonic antigen (CEA) on CdTe/CdSe quantum dot (QD)-enzyme-impregnated paper by coupling with a bioresponsive controlled-release system from DNA-gated mesoporous silica nanocontainers (MSNs). The assay was carried out in a centrifuge tube by using glucose-loaded MSNs with a CEA aptamer and a QD-enzyme-paper attached on the lid. Initially, single-strand complementary DNA to a CEA aptamer was covalently conjugated to the aminated MSN, and then glucose (enzyme substrate) molecules were gated into the pore with the help of the aptamer. Glucose oxidase (GOD) and CdTe/CdSe QDs were coimmobilized on paper for the visual fluorescence signal output. Upon target CEA introduction in the detection cell, the analyte specifically reacted with the immobilized aptamer on the MSN to open the pore, thereby resulting in the glucose release. The released glucose was oxidized by the immobilized GOD on paper to produce gluconic acid and hydrogen peroxide, and the latter quenched the fluorescence of CdTe/CdSe QDs, which could be determined by the naked eye on a portable smartphone and a commercial fluorospectrometer. Under optimal conditions, the PAD-based sensing system enabled sensitive discrimination of target CEA against other biomarkers or proteins in a linear range of 0.05-20 ng mL(-1) with a limit of detection of 6.7 pg mL(-1) (ppt). In addition, our strategy displayed high specificity, good reproducibility, and acceptable accuracy for analyzing human serum specimens with a commercial human CEA ELISA kit. Importantly, this methodology offers promise for simple analysis of biological samples and is suitable for use in the mass production of miniaturized devices, thus opening new opportunities for protein diagnostics and biosecurity.
- Alphavirus-Based Vaccines. [Journal Article]
- MMMethods Mol Biol 2017; 1581:225-242
- Alphavirus-based vectors have been engineered from Semliki Forest virus, Sindbis virus, and Venezuelan equine encephalitis virus and applied for vaccine development. Immunization in preclinical anima...
Alphavirus-based vectors have been engineered from Semliki Forest virus, Sindbis virus, and Venezuelan equine encephalitis virus and applied for vaccine development. Immunization in preclinical animal models has been conducted with naked RNA replicons, recombinant viral particles and layered DNA-RNA vectors. Most commonly, the targets for the immunization have been viral surface proteins and tumor antigens, which have elicited strong immune responses and even provided protection against challenges with lethal doses of virus and tumor cells, respectively. As alphaviruses also cause epidemics, vaccines have been developed against Chikungunya virus. Despite the success in several animal smodels only a few clinical trials have been conducted in humans, so far.
- Environmental impacts of genetically modified plants: A review. [Review]
- EREnviron Res 2017 Mar 27
- Powerful scientific techniques have caused dramatic expansion of genetically modified crops leading to altered agricultural practices posing direct and indirect environmental implications. Despite th...
Powerful scientific techniques have caused dramatic expansion of genetically modified crops leading to altered agricultural practices posing direct and indirect environmental implications. Despite the enhanced yield potential, risks and biosafety concerns associated with such GM crops are the fundamental issues to be addressed. An increasing interest can be noted among the researchers and policy makers in exploring unintended effects of transgenes associated with gene flow, flow of naked DNA, weediness and chemical toxicity. The current state of knowledge reveals that GM crops impart damaging impacts on the environment such as modification in crop pervasiveness or invasiveness, the emergence of herbicide and insecticide tolerance, transgene stacking and disturbed biodiversity, but these impacts require a more in-depth view and critical research so as to unveil further facts. Most of the reviewed scientific resources provide similar conclusions and currently there is an insufficient amount of data available and up until today, the consumption of GM plant products are safe for consumption to a greater extent with few exceptions. This paper updates the undesirable impacts of GM crops and their products on target and non-target species and attempts to shed light on the emerging challenges and threats associated with it. Underpinning research also realizes the influence of GM crops on a disturbance in biodiversity, development of resistance and evolution slightly resembles with the effects of non-GM cultivation. Future prospects are also discussed.
- Instant, Visual, and Instrument-Free Method for On-Site Screening of GTS 40-3-2 Soybean Based on Body-Heat Triggered Recombinase Polymerase Amplification. [Journal Article]
- ACAnal Chem 2017 Apr 18; 89(8):4413-4418
- On-site monitoring the plantation of genetically modified (GM) crops is of critical importance in agriculture industry throughout the world. In this paper, a simple, visual and instrument-free method...
On-site monitoring the plantation of genetically modified (GM) crops is of critical importance in agriculture industry throughout the world. In this paper, a simple, visual and instrument-free method for instant on-site detection of GTS 40-3-2 soybean has been developed. It is based on body-heat recombinase polymerase amplification (RPA) and followed with naked-eye detection via fluorescent DNA dye. Combining with extremely simplified sample preparation, the whole detection process can be accomplished within 10 min and the fluorescent results can be photographed by an accompanied smart phone. Results demonstrated a 100% detection rate for screening of practical GTS 40-3-2 soybean samples by 20 volunteers under different ambient temperatures. This method is not only suitable for on-site detection of GM crops but also demonstrates great potential to be applied in other fields.
- CTG repeat-targeting oligonucleotides for down-regulating Huntingtin expression. [Journal Article]
- NANucleic Acids Res 2017 Feb 17
- Huntington's disease (HD) is a fatal, neurodegenerative disorder in which patients suffer from mobility, psychological and cognitive impairments. Existing therapeutics are only symptomatic and do not...
Huntington's disease (HD) is a fatal, neurodegenerative disorder in which patients suffer from mobility, psychological and cognitive impairments. Existing therapeutics are only symptomatic and do not significantly alter the disease progression or increase life expectancy. HD is caused by expansion of the CAG trinucleotide repeat region in exon 1 of the Huntingtin gene (HTT), leading to the formation of mutant HTT transcripts (muHTT). The toxic gain-of-function of muHTT protein is a major cause of the disease. In addition, it has been suggested that the muHTT transcript contributes to the toxicity. Thus, reduction of both muHTT mRNA and protein levels would ideally be the most useful therapeutic option. We herein present a novel strategy for HD treatment using oligonucleotides (ONs) directly targeting the HTT trinucleotide repeat DNA. A partial, but significant and potentially long-term, HTT knock-down of both mRNA and protein was successfully achieved. Diminished phosphorylation of HTT gene-associated RNA-polymerase II is demonstrated, suggestive of reduced transcription downstream the ON-targeted repeat. Different backbone chemistries were found to have a strong impact on the ON efficiency. We also successfully use different delivery vehicles as well as naked uptake of the ONs, demonstrating versatility and possibly providing insights for in vivo applications.
New Search Next
- Immunogenicity of Candidate MERS-CoV DNA Vaccines Based on the Spike Protein. [Journal Article]
- SRSci Rep 2017 Mar 23; 7:44875
- MERS-coronavirus is a novel zoonotic pathogen which spread rapidly to >25 countries since 2012. Its apparent endemicity and the wide spread of its reservoir host (dromedary camels) in the Arabian Pen...
MERS-coronavirus is a novel zoonotic pathogen which spread rapidly to >25 countries since 2012. Its apparent endemicity and the wide spread of its reservoir host (dromedary camels) in the Arabian Peninsula highlight the ongoing public health threat of this virus. Therefore, development of effective prophylactic vaccine needs to be urgently explored given that there are no approved prophylactics or therapeutics for humans or animals to date. Different vaccine candidates have been investigated but serious safety concerns remain over protein or full-length spike (S) protein-based vaccines. Here, we investigated the immunogenicity of naked DNA vaccines expressing different fragments of MERS-CoV S protein in mice. We found that plasmids expressing full-length (pS) or S1-subunit (pS1) could induce significant levels of S1-specific antibodies (Abs) but with distinct IgG isotype patterns. Specifically, pS1 immunization elicited a balanced Th1/Th2 response and generally higher levels of all IgG isotypes compared to pS vaccination. Interestingly, only mice immunized with pS1 demonstrated significant S1-specific cellular immune response. Importantly, both constructs induced cross-neutralizing Abs against multiple strains of human and camel origins. These results indicate that vaccines expressing S1-subunit of the MERS-CoV S protein could represent a potential vaccine candidate without the possible safety concerns associated with full-length protein-based vaccines.