Micro DNA

Controlled alignment of long DNA nanofibers is challenging. This communication reports a method to align human genomic DNA with nearly unlimited length using lithographically produced micro-patterns of self-assembled monolayers (SAMs) with positively charged terminal groups. The micro-patterns act as local DNA reservoirs to supply DNAs for nanofiber formation, and can also stretch and align DNA nanofibers to form an ordered array by controlling the dewetting profile. By reducing the size and inter-patch distance of a micro-patch, a nearly uniform array of long DNA nanofibers can be patterned over a large area...

Leptospirosis is a worldwide zoonosis caused by pathogenic Leptospira spp. The severity of leptospirosis vary from mild, flu-like disease to a more severe form, Weil's disease causing jaundice, hemorrhage, renal failure, and even death. Every year, 300,000‒500,000 cases of severe leptospirosis are reported around the world, with the case fatality rate being 10‒30%. The usual diagnostic tools for leptospirosis are 1) direct observation of leptospires in blood and urine under dark-field microscope, 2) isolation of leptospires from blood, cerebrospinal fluid (CSF), or urine samples by culture, 3) microscopic agglutination test (MAT) to detect anti-Leptospira antibodies in serum, and 4) PCR to detect Leptospira DNA...

HYPOTHESIS: The miR-34a/Bcl-2 signaling pathway may play a role in the mechanisms related to age-related hearing loss (AHL) in the auditory cortex. BACKGROUND: The auditory cortex plays a key role in the recognition and processing of complex sound. It is difficult to explain why patients with AHL have poor speech recognition, so increasing numbers of studies have focused on its central change. Although micro (mi)RNAs in the central nervous system have recently been increasingly reported to be associated with age-related diseases, the molecular mechanisms of AHL in the auditory cortex are not fully understood...

We investigate the conformation and dynamics of a semi-flexible polymer near an attractive plane or a cylindrical post using Langevin dynamics. We characterize the transition from the desorbed to absorbed state and quantify how absorption depends on the attraction interaction, polymer molecular weight, polymer flexibility, intra-polymer interaction, and micro-confinement. We find that the critical point of adsorption for ideal flexible polymers only weakly depends on confinement. However, the critical point of adsorption increases significantly for self-avoiding flexible polymers and under confinement, deviating from scaling theory predictions...

Regeneration of complex bone defects remains a significant clinical challenge. Multi-tool biofabrication has permitted the combination of various biomaterials to create multifaceted composites with tailorable mechanical properties and spatially controlled biological function. In this study we sought to use bioprinting to engineer nonviral gene activated constructs reinforced by polymeric micro-filaments. A gene activated bioink was developed using RGD-γ-irradiated alginate and nano-hydroxyapatite (nHA) complexed to plasmid DNA (pDNA)...

Implantation of reporter-labeled tumor cells in an immunocompetent host involves a risk of their immune elimination. We have studied this effect in a mouse model of breast cancer after the orthotopic implantation of mammary gland adenocarcinoma 4T1 cells genetically labelled with luciferase (Luc). Mice were implanted with 4T1 cells and two derivative Luc-expressing clones 4T1luc2 and 4T1luc2D6 exhibiting equal in vitro growth rates. In vivo, the daughter 4T1luc2 clone exhibited nearly the same, and 4T1luc2D6, a lower growth rate than the parental cells...

Over the years, issues associated with non-biodegradable polymers have paved the way for biodegradable polymers in the domain of pharmaceutical and biomedical sciences. Poly (lactic-co-glycolic acid) (PLGA) is considered one of the most thrivingly synthesized biodegradable polymers. To formulate polymeric nanostructures, PLGA has attained noteworthy attention due to its controllable properties, complete biodegradability and biocompatibility, well defined formulation techniques and easy processing. This review focuses on fabrication techniques of PLGA based nanostructures and their advanced biomedical applications covering drug delivery and in-vivo imaging...

PURPOSE: Even though the first ultraviolet microbeam was described by S. Tschachotin back in 1912, the development of sophisticated micro-irradiation facilities only began to flourish in the late 1980s. In this article, we highlight significant microbeam experiments, describe the latest microbeam irradiator configurations and critical discoveries made by using the microbeam apparatus. MATERIALS AND METHODS: Modern radiological microbeams facilities are capable of producing a beam size of a few micrometers, or even tens of nanometers in size, and can deposit radiation with high precision within a cellular target...

Stretching single chromosomal DNA fibers in nanofluidic devices has become a valuable tool for studying the genome and more recently the epigenome. Although nanofluidic technology has been extensively used in single molecular DNA analysis, compared to bare DNA, much less work has been done to elongate chromatin, and only a few studies utilize more biologically relevant samples such as native eukaryotic chromatin. Here, we provide a method for stretching and imaging individual chromatin fibers within a micro- and nanofluidic device...

In this study, a xenogeneic DNA vaccine encoding for human vascular endothelial growth factor receptor-2 (hVEGFR-2) was evaluated in two murine tumor models, the B16-F10 melanoma and the EO771 breast carcinoma model. The vaccine was administered by intradermal injection followed by electroporation. The immunogenicity and the biological efficacy of the vaccine were tested in (1) a prophylactic setting, (2) a therapeutic setting, and (3) a therapeutic setting combined with surgical removal of the primary tumor...

BACKGROUND: Next generation sequencing based tumor tissue genotyping involves complex workflow and a relatively longer turnaround time. Semiconductor based next generation platforms varied from low throughput Ion PGM to high throughput Ion Proton and Ion S5XL sequencer. In this study, we compared Ion PGM and Ion Proton, with a new Ion S5XL NGS system for workflow scalability, analytical sensitivity and specificity, turnaround time and sequencing performance in a clinical laboratory. METHODS: Eighteen solid tumor samples positive for various mutations as detected previously by Ion PGM and Ion Proton were selected for study...

BACKGROUND: Nano- and microscale copper oxide particles (CuO NP, CuO MP) are applied for manifold purposes, enhancing exposure and thus the potential risk of adverse health effects. Based on the pronounced in vitro cytotoxicity of CuO NP, systematic investigations on the mode of action are required. Therefore, the impact of CuO NP, CuO MP and CuCl2 on the DNA damage response on transcriptional level was investigated by quantitative gene expression profiling via high-throughput RT-qPCR...

We evaluated DNA damage levels of different categories of workers exposed to hazards inside electronics factories in Southern China. To find out the most dangerous risk factor, a cross-sectional study was conducted on a total of 584 exposed subjects and 138 controls in an electronics factory in Southern China, where the electronics industry is prevalent. The exposed hazards included isopropanol (IPO), lead, noise, video display terminals (VDT), lead in a high-temperature (high-temp) environment, and IPO in a high-temp environment...

SCOPE: Scientific evidence suggests that folic acid (FA) supplementation protects the healthy colonic mucosa from neoplastic transformation but may promote the progression of precancerous lesions. The underlying molecular mechanisms are not fully understood. Therefore, we explored, if high physiological FA doses provoke changes in (i) promoter-specific DNA methylation (ii) expression of cancer-associated micro RNAs (miRNAs) and (iii) inflammatory mediators in human neoplastic and non-neoplastic colonic cell lines...

With the advancement of digital microfluidics technology, applications such as on-chip DNA analysis, point of care diagnosis and automated drug discovery are common nowadays. The use of Digital Microfluidics Biochips (DMFBs) in disease assessment and recognition of target molecules had become popular during the past few years. The reliability of these DMFBs is crucial when they are used in various medical applications. Errors found in these biochips are mainly due to the defects developed during droplet manipulation, chip degradation and inaccuracies in the bio-assay experiments...

Monodispersity and fast generation are innate advantages of microfluidic droplets. Other than the normally adopted simple Newtonian fluids such as a water/oil emulsion system, fluids with complex rheology, namely, non-Newtonian fluids, which are being widely adopted in industries and bioengineering, have gained increasing research interest on the microscale. However, challenges occur in controlling the dynamic behavior due to their complex properties. In this sense, the AC electric field with merits of fast response and easiness in fulfilling "Lab on a chip" has attracted our attention...

Epigenetic influences have been postulated to affect the course of endometriosis. DNA methyltransferases, estrogen and progesterone receptors, micro-RNAs, and histone deacetylators, have shown differential expression in endometriosis compared with normal endometrium. Others such as aromatase, Steroid Factor-1, COX-2, and Homeobox A10 also have epigenetic modifications in endometriosis. Limitations in this area of research include heterogeneity in study design, patient populations, and methods of analysis. Larger, controlled studies are needed...

Agrobacterium tumefaciens mediated T-DNA integration is a common tool for plant genome manipulation. However, there is controversy regarding whether T-DNA integration is biased towards genes or randomly distributed throughout the genome. In order to address this question, we performed high-throughput mapping of T-DNA-genome junctions obtained in the absence of selection at several time points after infection. T-DNA-genome junctions were detected as early as 6 hours post-infection. T-DNA distribution was apparently uniform throughout the chromosomes, yet local biases toward AT-rich motifs and T-DNA border sequence micro-homology were detected...

AIM: To investigate the p53 and O(6)-methylguanine DNA methyltransferase (MGMT)5' upstream sequence gene promoter regions for single nucleotide polymorphisms and explore the p53 gene 5' upstream sequence consisting of two haplotypes to provide a genetic marker for the incidence of laryngeal squamous cell carcinoma. MATERIALS AND METHODS: We included 96 cases of laryngeal squamous cell carcinoma and 102 controls. We used SNaPshot micro-sequencing analysis of the MGMT promoter region for four single nucleotide polymorphisms and p53 gene 5' upstream sequence loci (rs1625649, rs2287499, rs2287498, rs228749) genotypes...

OBJECTIVES: Plasmid mediated quinolone resistance (PMQR) genes are increasingly detected worldwide. However, in Morocco a few studies have been carried out. The aim of this study was to investigate the prevalence of these determinants among Escherichia coli and Klebsiella spp isolated from North-West of Morocco. METHODS: The prevalence of PMQR genes was investigated among 398 E. coli and 118 Klebsiella spp clinical isolates collected between 2012 and 2015 from North-West of Morocco...