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Background: RNA antisense emerging as novel candidates for therapeutic purposes. As an RNA, miR-34a involves in P53 function, and triggers cancer cells apoptosis. The clinical applications of miRNAs face some limitation which can be potentially resolved using exosome as a transporting vehicle. Aims: The aim of this study is to create a cell factory to generate miR34a-enriched exosomes. Methods: First exosome specific sequences were inserted into miR34a. The resulting miR34a gene were transduced HEK293T cells genome with a lentiviral system. In the structure of miR34a gene 6 nucleotides were substituted to increase its packaging rate into exosomes. To maintain the secondary structure, stability and expression of the miRNA gene, changes to the miR34a gene were made using PCR Extension. Results: The results confirmed the created changes in the miR34a gene do not affect its secondary structure. The energy level of the manipulated miR34a gene was not changed in comparison with the original one. Conclusion: Our results suggested that the induced mutation (replacing 6 nucleic acids at the 3' end of miR34a) increases loading of miR34a into the exosome by 3-fold.

The need for a healthy market in the rapid and accurate screening of a variety of pathogenic agents and toxins in the environment and food has led to an increase in the development of new biosensors, which have ideal characteristics, such as high sensitivity and specificity with rapid detection and simple preparation of the sample. Among the food contaminants, mycotoxins have been identified as a major challenge for the food industry, and rapid and accurate detection has attracted the attention of food inspection and monitoring organisations. In this study, a nanomolecular detection method is described using aflatoxin B1 (AFB1)-specific aptamers attached to streptavidin-coated magnetic nanoparticles. A prominent feature of the AFB1-specific aptamers is a guanine-rich (G-rich) sequence with a G-quadruplex structure after capturing AFB1 molecules and mimicking peroxidase activity. The enzymatic reaction evaluated in the presence of chromogenic substrate and measurement is done by a smartphone-specific application for colorimetric measurement. The results indicated that the assay could measure AFB1 in rice, flour, seed, maize, and pistachio. In addition, the application of hybrid nanomaterial technology resulting from the binding of biotin-labelled aptamers to the surface of streptavidin-coated magnetic nanoparticles minimises preparation and treatment of samples, improves results, and consequently reduces false negative and positive responses in the detection field. This study may eventually lead to the design and development of a fast, sensitive, specific, and on-site AFB1-based nanomolecular colorimetric detection system via a smartphone-based application that can be readily accessible to all applicants, from professionals to manufacturers of foodstuffs.

Background: Methicillin Resistance Staphylococcus aureus (MRSA) could be considered as a major concern in medicine can cause nosocomial infection and bacteremia, especially in patients using catheter and household medical devices. Methods: Using molecular diagnostic methods are important for identification of MRSA from the Methicillin Sensitive Staphylococcus aureus (MSSA). Here we described a fluorescent assay using biotin-labelling Loop-mediated isothermal amplification (LAMP) method assisted with streptavidin-coated Quantum Dots (QDs) for detection of MRSA. For comparison, another fluorescent assay using LAMP assisted with Green Viewer (GV; a fluorescent dye) was applied for detection of MRSA. The mecA gene was selected as the target for amplification by LAMP and for biotin-labeling of the LAMP amplicons, biotin-11-dUTP was mixed with the dNTPs (deoxy Nucleotide Phosphates) in LAMP reaction. For determining the clinical performance of the developed assay, 30 blood samples with MRSA positive results were tested with QD-LAMP, the conventional LAMP, GV-LAMP, and Polymerase Chain Reaction (PCR). Results: Obtained results indicated that % sensitivity of QD-LAMP was 86.66% for detection of mecA positive MRSA samples; however, the Limit of Detection (LoD) of QD-LAMP was 1.5×104 Colony Forming Unit (CFU). Conclusion: The results suggested that the QD-LAMP assay was easy to operate and could be used for detection of MRSA in parallel to the blood culture with less sensitivity for detection of bacteremia and pediatric septicemia with low counts of MRSA.

AIM AND BACKGROUND Azoles as antifungal drugs have been used to treat leishmaniasis for many years. Several evidences suggesting that the primary target of azoles is the heme protein, which co-catalyzes cytochrome P-450-dependent 14α-demethylation of lanosterol. Little is known about the structural changes caused by azoles with atomic force microscopy (AFM) or scanning electron microscopy (SEM). In the current work, several patented antileishmanial agents reviewed (US8809555) (US 0269803 A1) (TW201802093 A). The present study aimed to determine ultrastructural damage in Leishmania major (L.major) induced by the newly synthesized azole. METHODS In this study, we investigated the morphological alterations of the parasite treated with our new synthesized azole namely trans-2-(4-chlorophenyl)-2,3-dihydro-3-(1Himidazol- 1-yl)-4H-1-benzopyran-4-one (IF-2) against L.major promastigotes stage using two high-resolution microscopic techniques: atomic force microscopy and scanning electron microscopy. RESULTS The results showed remarkable topographical and morphological alterations in the cell membrane at promastigote stage of L. major treated with the potent investigated azole (IF-2) ( IC50 values ≤8.9 µg/mL). Both techniques revealed membrane damage and also losing the flagellum in the observed cells. CONCLUSION Our results strongly confirm the Leishmania cell wall as a potent target for the new synthesized azole (IF-2). Accordingly, focus on membrane integrity and glycoconjugates of Leishmania parasite to design new therapeutic agents is recommended.

Methicillin ResistanceUsing molecular diagnostic methods are important for identification ofObtained results indicated that % sensitivity of QD-LAMP was 86.66% for detection ofThe results suggested that the QD-LAMP assay was easy to operate and could be used for detection of

The application of nanotechnology in medicine and pharmaceutical purpose suggested a novel procedure in the nanotechnology terminology as nanomedicine. There is a wide range of applications for nanotechnology in medicine, such as the use of nanocarriers in drug delivery systems. Recently a remarkable attention to DNA has been made through its amazing functionality and its nature as a nanomaterial in biological systems. Since DNA is a biocompatible, the use of DNA as a nanomaterial in medicine has shown a great perspective of rational engineering of DNA nanostructures. According to new approaches in treatment of diseases in gene levels, gene therapy, using DNA as a nanomedicine possesses an important role in the medical sciences as the researchers published enormous papers and patents in the fields, for instance, the applications of DNA and DNA-based nanostructures as drug or gene nanocarriers, DNA-based diagnostics and DNA nanovasccines. Here, some examples of DNA-based nanomedicine in the patent frame were reviewed.

Background: Emergence and prevalence of multi drug resistance strains such as Methicillin-Resistant Staphylococcus aureus (MRSA) call for new antibacterial option. Endolysins as a new option is suggested. The phage display technique is suggested for production of recombinant endolysins. The recombinant endolysins displayed nano phages specifically lysis bacteria, which penetrate to the depth of tissue and the effective dose is reduced. Methods: CHAPK gene was ligated in T7Select vector arms in T7Select10-3b cloning kit. To produce recombinant nano phages, ligation reaction was added directly to the packaging extract. Recombinant nano phages were amplified by Double Layer Agar assay (DLA). The recombinant nano phages were characterized using TEM. Size of recombinant nano phages was determined using DLS. The spot test was performed to confirm CHAPk -displayed on the surface of nano phages. The turbidimetry was used to investigate lytic activity of recombinant nano phages against MRSA ATCC No. 33591. Results: The results showed recombinant nano phages belonged to order Caudovirales and family Podoviridae with titer 2×107 PFU/ml. According to the results of DLS, size of recombinant nano phages was 71 nm. Formation inhibition zone confirmed the presence of CHAPk on the surface of nano phage phenotypically. The turbidimetry showed lytic activity recombinant nano phages against MRSA after 5 min. Conclusion: This study suggests that CHAPk -displayed nano phages can be effective in MRSA infections.

Nucleic acid amplification of Covid-19 RNA is the main subject for molecular detection of SARS-COV-2. However, the employment of target amplification methods such as PCR needs a converting step for Covid-19 RNA to DNA template to be amplified. In addition, Covid-19 RNA isolation needs some RNA extraction kits that their providing could increase the time and costs for the molecular detection of the virus. In this study, we introduced a magnetic nanoprobe that could be used to capture and amplify Covid-19 RNA through an isothermal amplification process, so-called nucleic acid sequence-based amplification, without needing to perform a separate step for the viral RNA converting to DNA template. By using engineered sequences appropriate to the target nucleic acid attached to the magnetic nanoparticles, identifying the target RNA from the virus could be possible by clumping the particles that could be seen with naked eyes. According to the isothermal amplification of the viral RNA via nucleic acid sequence-based amplification assisted with the magnetic nanoprobe, the nanomolecular method eliminated the need for special pieces of equipment and the time for detection of Covid-19 in specimens.

Nowadays, the detection of albumin and determination of its concentration for early diagnosis of kidney diseases has attracted considerable attention as a simple and rapid method. In this work, two methods for detection and determination of albumin concentration were investigated and compared by using gold nanorods (GNRs) and spectrophotometry of their interaction with bovine serum albumin (BSA). By the changes in the typical synthesis protocol, GNRs' samples were synthesized and characterized. Synthesized GNRs were mixed with different concentrations of BSA. Ultraviolet–Visible (UV–Vis) spectroscopy and X-ray Fluorescence (FL) spectroscopy were applied to examine the mixed samples. The change of absorption spectrum in the UV region showed the detection limit of BSA concentration of 0.2 mg/mL. The detection limit of BSA concentration of 0.05 mg/mL was obtained from the investigation of absorption spectrum in visible-infrared (Vis-IR) regions. However, the study of the FL spectra proved the detection limit is as low as 0.0013 mg/mL. Therefore, it was found out that very low concentrations of albumin could be very accurately detected by FL spectroscopy. Also, comparing of the spectra obtained from the samples at various time intervals indicated that the measurement of concentration is possible after 1–20 min of mixing GNRs and BSA.

Described here a methodology for arraying of magnetic nanoparticles (MNPs) on the surface of DNA nanotubes (DNTs). Positioning of magnetic nanoparticles at exterior surface of DNTs were shaped after self-assembling of oligonucleotide staples within an M13mp18 DNA scaffold via an origami process. The staples were partially labeled with biotin to be arrayed at the surface of DNTs. Gel retardation assay of the DNTs carrying magnetic nanoparticles indicated a reversely behavioral electrophoretic movement in comparison to the nanotubes have been demonstrated previously. Also, high resolution transmission electron microscopy confirmed positioning magnetic nanoparticles at the exterior surface of DNTs, correctly. Ultrastructural characteristics of these DNA nanotubes using atomic force microscopy demonstrated topographic heights on their surfaces formed through positioning of magnetic nanoparticles outside the tubules. This nanoarchitecture would be potential for multiple arraying of nanoparticles that those be useful as functionalized chimeric nanocarriers for developing novel nanodrugs and nanobiosensors.

Trichostrongylus species remain one of the major health challenges in the tropical and summer rainfall regions worldwide. Identification of strongylid species diagnostic methods is vital for obtaining a deep understanding of the epidemiology, population biology, anthelmintic treatment efficacy, and drug resistance in order to design effective parasite control strategies. We evaluated a multiplex RE-PCR for the diagnosis of key Trichostrongylus spp. Genomic DNA amplification of Trichostrongylus colubriformis, Trichostrongylus axei and Trichostrongylus vitrinus was achieved as standard sample using specific primers located in the second internal transcribed spacer (ITSII) of nuclear ribosomal DNA (rDNA). The mentioned method was based on isolation of Trichostrongylus ova from human fecal samples using Willis method, the extraction of ova genomic DNA samples, followed by rDNA ITSII PCR and one-step multiplex RE-PCR using three restriction enzymes of HinfI, DraI, and MseI. The multiplex RE-PCR technique provides a useful tool for discriminating all Trichostrongylus spp., being useful for diagnostic, epidemiological, ecological studies, and control programs. This method is rapid, especially when numerous restriction enzymes are required for species differentiation or identification.

Thalassemia is major monogenic disorder. A practical way to prevention of Thalassemia is identification of carries couples; genetic counseling and offer prenatal diagnose services for both carrier couples. Routine prenatal diagnose are chorionic villus sampling and amniocentesis, but both of them are invasive method and they can be ended to bleeding and pregnancy loss. Recently non invasive prenatal diagnosis has been done by researchers for early detection of pre-eclampsia, chromosomal aneuploidies, RhD-genotyping. Regarding non invasive prenatal diagnosis of ?- Thalassemia, detection of paternally inherited mutation in maternal plasma is possible. If the fetus inherited normal paternal allele the performance of invasive method it is not necessary, so this method can be eliminate 50% performance of routine prenatal diagnosis.Bangladesh Journal of Medical Science Vol.16(2) 2017 p.196-202

Gold nanostructures in general and gold nanorods in particular due to their plasmon resonance has been employed for many applications, such as biosensors. For the biosensors uses, gold nanorods remain popular and reproducibility of them is the most important and critical. In the present work we used six different CTAB (Hexadecyltrimethylammonium bromide) products and one BDAC (Benzyldimethylhexadecylammonium chloride) with varying silver nitrate concentration in the seed-mediated growth of gold nanostructures. We synthesized gold nanorods with varying aspect ratio up to 5.5 with a longitudinal surface plasmon resonance peak from 670 to 950 nm. We obtained excellent rod-shape gold nanostructures witch were reliable and reproducible with our method based on common seed-mediated growth. The synthesized nanostructures were characterized by UV–visible spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction (XRD). Here, we report our method in more detail as a user-friendly guide for the production of gold nanorods and tuning of their aspect ratios.

A nanodiagnostic genotyping method was presented for point mutation detection directly in human genomic DNA based on ligase reaction coupled with quantum dots and magnetic nanoparticle-based probes. For this purpose, allele-specific probes, including a biotin-labeled common probe and two biotin-labeled allele-specific probes were designed for mutant and wild alleles of human beta globin gene (IVS-II-I G → A point mutation). When genomic DNA carried the mutation site, the common probe and allele-specific probe were ligated to form exponential amplified biotin-labeled fluorescence ligation products. These ligated products were captured by streptavidin-coated magnetic nanoparticles at one end and then attached to a QD 605-streptavidin conjugate at the other end to be detected fluorescently. Thereafter, the genotypes were identified conveniently according to the fluorescence color of quantum dots using a rotor-gene 6000Q real-time rotary analyzer. The results demonstrated the sensitivity and specificity percentages of this nanomolecular mutation detection method were 85.45% and 95.77% respectively. In addition, this method could be a high throughput and high sensitivity detection system that represents suitable non-PCR based nanodiagnostics for detection of other point mutations.

BACKGROUND: Thalassemia is one of the most common genetic health problems in the world. More than 200 different mutations have been identified in the beta-globin gene and among the 24 β-globin gene mutations in β-thalassemia carriers in the north of Iran IVSII-I G>A mutation has the highest frequency. Using fast, inexpensive, simple and reliable methods for the detection of the mutations in β-thal carriers is very important in prenatal diagnosis, and introduction of alternative methods to the existing ones can help to simplify the detection of mutations. Since its introduction, different methods derived from LAMP have been widely used for SNPs detection. AIM: This study was aimed to design a new method for the detection of IVSII-I G>A mutation on β-globin gene based on AS - LAMP technique. METHODS: Primer explorer V5 software was used for the design of LAMP primers. Three sets of primers were designed. In the first set, the BIP primers were exactly complementary to the normal and mutant alleles. In the second set, 1 nucleotide (T) was inserted at the 5’ end of BIP primers, and in the last set, one nucleotide at the 5’ end of BIP primer was changed. The other required primers for the LAMP reaction (FIP, B3, and F3) were the same for all 3 sets of primers. The LAMP reaction was applied on three DNA samples (Wild type, Heterozygote and Homozygote for IVSII-I G>A mutation) and synthetic DNA. RESULTS: The results of the present study showed that LAMP reaction using three sets of primers could not successfully detect the IVSII-I G > A mutation among subjects DNA sample and synthetic DNA. CONCLUSION: Although several studies have successfully used ARMS-LAMP method to detect the SNPs, and other studies use a variety of methods to identify IVSII-I G>A mutation, the present study was unable to differentiate between a normal allele and IVSII-I G>A mutation. Hence further studies are recommended to consider redesigning of primer set, DNA concentration and using commercial LAMP Master Mix to detect the mutation.

Melanoma bears the highest mortality rate in skin cancers. The unique properties of chitosan-based nanofibers provide a great potential to formulate an effective topical drug delivery system. With the emphasis on Colchicine systemic toxicity as an obstacle against the administration in systemic chemotherapy and considering its superiority over approved chemotherapeutic agents for melanoma management, it was chosen to be formulated in a nanofiber based topical drug delivery system. The optimization assay was conducted by AFM and SEM based on the morphology, topographic data, and mean diameter size of the nanofibers. Other characterization studies include FTIR, XRD, STA, contact angle measurement, tensile test, ex vivo skin permeation, deposition analysis, release kinetic and anti-melanoma efficiency against A-375 cell line. As a result, significant colchicine deposition in the skin with remarkable cytotoxicity against melanoma cell line makes it a desirable formulation to be administered as a topical or local reservoir system for neoadjuvant chemotherapy before other interventions and adjuvant therapy of tumors after surgery and, also, for other skin diseases with dose adjustment. Besides, the observed first order release kinetic behavior through the skin could suggest it as a transdermal colchicine delivery system which improves its efficiency in systemic indications.

Background Methicillin-resistant Staphylococcus aureus (MRSA) is a well-known pathogen that causes serious diseases in humans. As part of the efforts to control this pathogen, an isolated bacteriophage, Siphoviridae, which specifically targets Methicillin-resistant Staphylococcus aureus (MRSA), was characterized. Aims The objective of this study was to characterize of a virulent bacteriophage (Siphoviridae) isolated from a NICU bathroom sink. Methods The MRSA strain was isolated from patient blood. The isolated strain was confirmed as MRSA using conventional methods. Phages were isolated from a NICU bathroom sink and activity was lytic as determined by spot test. Titer phage lysate was measured by the Double Layer Agar (DLA) technique. The morphology was found with electron microscopy. The single-step growth curve was plotted. Results Electron microscopy showed the phage as a member of the family Siphoviridae, serogroup A and F. The isolated phage was capable of lytic activity against methicillin-resistant Staphylococcus aureus (MRSA) strain as shown by spot test. By DLA, the titre of the phages was determined to be 10×108PFU/ml. The single-step growth curve showed that the latent period of the isolated bacteriophage was 30 min and the total number of viable progeny per infected host, burst size, was 2600 PFU/infected host. Conclusion In this study, two phages were isolated and characterized from a NICU bathroom sink, from the Siphoviridae family, which specifically targetsmethicillin-resistant Staphylococcus aureus (MRSA).

The discovery of fetal DNA (f-DNA) opens the possibility of early non-invasive procedure for detection of paternally inherited mutation of beta-thalassemia. Since 2002, some studies have examined the sensitivity and specificity of this method for detection of paternally inherited mutation of thalassemia in pregnant women at risk of having affected babies. We conducted a systematic review of published articles that evaluated using this method for early detection of paternally inherited mutation in maternal plasma. A sensitive search of multiple databases was done in which nine studies met our inclusion criteria. The sensitivity and specificity was 99 and 99 %, respectively. The current study found that detection of paternally inherited mutation of thalassemia using analysis of cell-free fetal DNA is highly accurate. This method could replace conventional and invasive methods.

Background The major problem in the management of burn wounds are infections. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the major cause of infection in burn wounds. Antibiotic resistant bacteria around the world has become a major therapeutic challenge. Bacteriophages and their lysine are suggested as an antimicrobial alternative agent. Phage display technique is suggested for production of recombinant lysine by Nano carrier technology. The approach of this study was to evaluate the potential of recombinant Nano phage efficacy in MRSA burn wound infection in vivo. Materials and methods The 3rd degree burn wounds were induced in 54 rats and infected with MRSA ATCC 33591 via the topical route in four groups. Burn wound size was measured in 0, 14, 21, 28 days. The efficacy of Nano phage gel was assessed on the basis of percentage collagen deposition, granulation tissue, neovascularization, fibroblastic maturity, re-epithelization, and scar formation in rats following treatment in 14, 21, 28 days. Results The results showed that the percentage of wound size were 3 cm on base line day and the average macroscopic wound healing rates were increased in the prevention groups receiving the recombinant Nano phage gel and natural phage gel, in the treatment groups with secondary infection receiving the recombinant Nano phage gel and the natural phage gel, and in the two control groups respectively. The average microscopic wound healing rates were increased in the prevention groups receiving the recombinant Nano phage gel and natural phage gel, in the treatment groups with secondary infection receiving the recombinant Nano phage gel and the natural phage gel, and in the two control groups respectively. Conclusions In conclusion the recombinant Nano phage gel is efficacy to treat and prevent MRSA burn wound infection.

Azoles as antifungal drugs have been used to treat leishmaniasis for many years. Several evidences suggesting that the primary target of azoles is the heme protein, which co-catalyzes cytochrome P-450-dependent 14α-demethylation of lanosterol. Little is known about the structural changes caused by azoles with atomic force microscopy (AFM) or scanning electron microscopy (SEM). In the current work, several patented antileishmanial agents reviewed (US8809555) (US 0269803 A1) (TW201802093 A). The present study aimed to determine ultrastructural damage in Leishmania major (L.major) induced by the newly synthesized azole.In this study, we investigated the morphological alterations of the parasite treated with our new synthesized azole namely trans-2-(4-chlorophenyl)-2,3-dihydro-3-(1Himidazol- 1-yl)-4H-1-benzopyran-4-one (IF-2) against L.major promastigotes stage using two high-resolution microscopic techniques: atomic force microscopy and scanning electron microscopy.The results showed remarkable topographical and morphological alterations in the cell membrane at promastigote stage of L. major treated with the potent investigated azole (IF-2) ( IC50 values ≤8.9 µg/mL). Both techniques revealed membrane damage and also losing the flagellum in the observed cells.Our results strongly confirm the Leishmania cell wall as a potent target for the new synthesized azole (IF-2). Accordingly, focus on membrane integrity and glycoconjugates of Leishmania parasite to design new therapeutic agents is recommended.

The demands for genotyping techniques with acceptable precision, accuracy, cost-effectiveness in high throughput formats made driving forces for continuous development of novel technologies. A wide range of mutation detection techniques based on polymerase chain reaction (PCR) have been introduced. The best alternatives were the isothermal amplification technologies that those did not require a thermal cycler. In this review, we aimed to describe the most known isothermal amplification techniques for SNP genotyping.

Described here is a methodology for fabrication of a sensitive colorimetric nanoassay for measurement of insulin using G-quadruplex aptamer arrays on DNA nanotubes (DNTs) coupled with magnetic nanoparticles. The spectroscopic findings (e.g. visible spectra, velocity assay and limit of detection determination) indicated a highly sensitive performance of this new nanoassay in comparison to those results obtained from the insulin assay with non-arrayed aptamers. The clinical performance statistics (i.e. paired sample t -test, Bland–Altman plot and scatter diagram) from the newly developed assay and the enzyme-linked immunosorbent assay suggested its reliable precision and its acceptable repeatability for measurement of insulin in human sera. This is, to our knowledge, the first study for the application of magnetic nanoparticle-coupled DNTs for carrying G-quadruplex aptamers for detection of biomolecules (such as insulin) in human serum.

The high-resolution melting (HRM) technique is fast, effective and successful method for mutation detection. The aim of this study was to determine the sensitivity and specificity of the HRM method for detection of a paternally inherited mutation in a fetus as a noninvasive prenatal diagnosis of β-thalassemia.Genomic DNAs were prepared from 50 β-thalassemia minor couples whose pregnancy was at risk for homozygous β-thalassemia. Ten milliliters of the maternal blood from each pregnant woman were collected and after separating plasma stored at -80 °C until analysis. The extracted DNAs were analyzed by HRM real-time PCR for detection of IVS-II-I (G-A) as a paternally inherited mutation. The gold standard was the result of a chorionic villus sampling by a standard reverse dot blotting test.The sensitivity and specificity of HRM real-time PCR were 92.6% and 82.6%, respectively. Also, the positive and negative predictive values were 86.2% and 90.47%, respectively.HRM real-time PCR was a sensitive and specific method for determining the paternally inherited mutation in the fetus at risk with thalassemia major.

The potential applications of scanning tunneling microscopy and atomic force microscopy for the characterizations of DNA nanotubes in nanoscale have been described here. The nanotubes were designed using the Cadnano software according to M13mp18 DNA as a scaffold. DNA nanotubes were fabricated using the origami technique assisted with ligase treatment subsequently. Transmission electron microscopy confirmed the morphology of DNA nanotubes. For the topographic characterization of DNA nanotubes, an atomic force microscope was used in comparison to a scanning tunneling microscope. The scanning tunneling microscopy results revealed a high-resolution topography of DNA nanotubes in the constant-current mode; however, more details of the self-assembly in DNA strands in nanotubes were explored by atomic force microscopy with contact mode (or constant height). Our findings suggested that those two microscopes could be candidates for ultrastructural characterizations of DNA nanotubes for obtaining two- and three-dimensional micrographs

The aim of the current investigation was to prepare and evaluate the potential use of solid lipid nanoparticles for the dermal delivery of spironolactone (SP). The spironolactone loaded SLN (SP-SLN) was prepared by emulsion-solvent evaporation method followed by ultrasonication. The properties of obtained SLNs were characterized by photon correlation spectroscopy (PCS), scanning tunneling microscopy (STM) and differential scanning calorimetry. FT-IR was also used to investigate any interaction between SP and excipients in the molecular level during the preparation of SLNs. The performance of the formulations was investigated in terms of drug release, skin permeation and also the retention of drug by the skin. The SP-SLNs presented spherical shape with the mean diameter, zeta potential and entrapment efficiency of 88.9 nm, −23.9 mV and 59.86%, respectively. DSC study showed that SP alone encapsulated in SLNs was in the amorphous form. FT-IR analysis revealed that there were hydrogen bond interactions between the SP alone and SLN components. The dissolution results revealed that the drug release from SP-SLNs was at least 4.9 times faster than original SP within the first 30 min. The cumulative amount of SP penetrated through rat skin from SP-SLNs was almost twofold that of the SP alone in 24 h after the administration. In vitro permeation studies indicated that SP-SLN may be a promising vector for use in the topical treatment. It can be concluded that SLNs provide good skin permeation for SP and may be a promising carrier for topical delivery of spironolactone offering the biphasic release pattern that might be interesting for topical application resulting in an effective treatment for skin disorders such as acne.

Described here is a simplified method for fabrication of DNA nanotubes using a minimum numbers of staple oligomers for DNA origami. For this purpose, the cylindrical nanotemplates with two sticky ends have been designed using caDNAno software. Then, the nanostructures were shaped in an optimized experimental condition via an origami-based self-assembly reaction. Finally, the produced nanostructures were joined together through their sticky ends using a ligase enzyme. Transmission electron microscope confirmed fabrication of these elongated nanotubes. In addition, high-resolution microscopy of DNA nanotubes by scanning tunnelling microscope indicated efficient attachments of the primarily DNA nanostructures via their sticky ends. The results demonstrated that a ligase treatment of cylindrical DNA nanostructures with the sticky ends made DNA nanotubes with standard shapes using minimum numbers of staples.

Described herein is a methodology for selectively capturing hepatitis C virus (HCV) particles from human plasma samples using aptamer-conjugated magnetic nanoparticles. The aptamers were specific for binding to the E1E2 glycoprotein of HCV. The nanoconjugate was confirmed using UV-visible and FTIR spectroscopy; moreover, the transmission electron micrographs demonstrated efficient capture of these nanoconjugates using magnetic force. Also, quantitative measurement of HCV particles in human plasma samples by real-time PCR confirmed the efficient removal of the viral load.

Context: Spread of Methicillin-resistant Staphylococcus aureus (MRSA) can cause serious and sometimes fatal diseases especially in children. Outbreaks and increasing the prevalence of antibiotic-resistant MRSA at pediatric hospital calls for the development of novel preservation techniques. Endolysins and bacteriophages have been used successfully to control bacterial infections in children. Endolysins were considered as a useful treatment especially for the pathogens without disturbing the normal flora, the low chance of bacterial resistance, and their ability to kill colonizing pathogens on mucosal surfaces. Herein, we aimed to review the effectiveness of endolysins of bacteriophage for controlling methicillin-resistant Staphylococcus aureus infections in children. Evidence Acquisition: This review was performed by searching studies indexed in international databases including PubMed, Scopus, Web of Science, Science Direct, as well as Google Scholar published from 2000 until 2016. Results: Experimental data show that endolysins of Staphylococcus aureus bacteriophage can be used to combat methicillin-resistant Staphylococcus aureus infections in children. Conclusions: Endolysins of bacteriophages could be effective for controlling a variety of methicillin-resistant Staphylococcus aureusinfections.

Beta-thalassemia (β-thalassemia) is a globally genetic diseases, and is most prevalent in the Middle East, particularly in Iran. Carrier detection and prenatal diagnosis are the best ways to managing it, and to prevent new community cases from emerging. We report on a simple method for rapid detection of the worst β-thalassemia point mutation in Iran (IVS-II-1 G>A), using a nano-based ligation assay, this was performed using probes with labeled magnetic nanoparticles and quantum dots. After optimizing the technique, 50 DNA samples were genotyped with this method. We found a frequency of 72% for IVSII-1 (G˃A) mutation (42% heterozygote, and 30% mutant homozygote) with a highly sensitive nano-based ligation genotyping system, offering excellent sensitivity and specificity for point mutation detection; it has been demonstrated to be inaccurate, sensitive, cost-effective, and rapid technique for single nucleotide polymorphism (SNP) genotyping.

Nanorods in nanotechnology called a specific type of morphology of nanoscale materials that their dimensions range is from 1 to 100 nm. Nanorods can be synthesized from metal or semi-conductive material with a surface to volume ratio of 3–5. One method of making nanorods is direct chemical method. Ligands compounds as a shape control agents cause growth the nanorods and create stretched and extended modes of them. In recent years, magnetic nanorods are one of the nanorods that have been raised in the field of nano medicine [Nath S, Kaittanis C, Ramachandran V, Dalal NS, Perez JM. Synthesis, magnetic characterization, and sensing applications of novel dextran-coated iron oxide nanorods. Chem Mater. 2009;21:1761–7.]. Superparamagnetic properties of magnetic nanorods causes to sensing be done with high accuracy. In addition, other applications of magnetic nanorods are in the field of separation and treatment [Hu B, Wang N, Han L, Chen ML, Wang JH. Magnetic nanohybrids loaded with bimetal core–shell–shell nanorods for bacteria capture, separation, and near-infrared photothermal treatment. Chemistry. 2015;21:6582–9.]. Therefore, in biomedical applications, the nanorods are used usually with biological molecules such as antibodies [Schrittwieser S, Pelaz B, Parak WJ, Lentijo-Mozo S, Soulantica K, Dieckhoff J, et al. Homogeneous protein analysis by magnetic core–shell nanorod probes. ACS Appl Mater Interfaces. 2016;8:8893–9.]. For this purpose, in the present work we will try to introduce magnetic nanorods and mention their different methods of synthesis and applications.

We describe a microfluidic method for rapid isothermal turbidimetric detection of the DNA of Mycobacterium tuberculosis. Loop-mediated isothermal amplification is accomplished in capillary tubes for amplifying DNA in less than 15 min, and sensitivity and specificity were compared to conventional loop-mediated isothermal amplification (LAMP). The method can detect as little as 1 pg mL−1 DNA in a sample. Results obtained with clinical specimens indicated 90 % sensitivity and 95 % specificity for microfluidic LAMP in comparison to culture methods. No interference occurred due to the presence of nonspecific DNAs. The findings demonstrate the power of the new microfluidic LAMP test for rapid molecular detection of microorganisms even when using bare eyes.

We describe here a nanodiagnostic colorimetric assay for 18S rRNA of Leishmania pathogens that uses nucleic acid sequence-based amplification (NASBA) and gold nanorods (GNRs). NASBA primers targeting 18S rRNA were used for amplification of RNA in an isothermal process. The electrostatic interactions between the phosphate groups of the RNA amplicons and the cetyl trimethylammonium bromide layer on the GNRs resulting in their aggregation. This phenomenon changes the color of the GNR solution from red to purple. Our data showed 100 % sensitivity and 80 % specificity with the colorimetric assay compared with results using reverse transcription polymerase chain reaction. The nanodiagnostic method we describe simplifies the detection of NASBA amplicons without the need for gel electrophoresis.

Background: The methicillin-resistant Staphylococcus aureus (MRSA) strain is now the most commonly reported antibiotic-resistant bacterium in clinical settings. Therefore, there is an urgent need to develop novel antibacterial agents to control this pathogen. Bacteriophages are a potential alternative treatment for MRSA infections. Objectives: The objective of this study was the isolation and characterization of MRSA phages from the sewage at a tertiary pediatric hospital. Methods: Two MRSA strains were isolated from patient blood. The isolated strains were confirmed as MRSA through the conventional methods. Phages were then isolated from the sewage at the tertiary pediatric hospital. Lytic activity was determined with a spot test, while the titers of phage lysates were measured using the DLA technique. The morphology was assessed using electron microscopy, and the latent period time and burst size were determined. Results: Electron microscopy showed MRSA phages’ resemblance to members of the family Siphoviridae, serogroups A and F. They exhibited a latent period of 70 minutes and a relatively burst size of 2,400 plaque-forming units (PFU)/infected cell. The titer of the phages was determined to be 3 × 109 PFU/mL using the by DLA technique. Conclusions: In this study, two phages from the family Siphoviridae were isolated and characterized from sewage at a tertiary pediatric hospital; these phages specifically target MRSA. Their presence may be one reason for the transfer of antibiotic resistance or virulence factors, resulting in transduction and the conversion of nonvirulent strains of Staphylococcus to virulent strains. Considering that phages through can be transferred to wards in an air-born manner, it is better to create negative pressure in the sewage pipes at hospitals until the phages can no longer transfer to the wards via aerosols.

The emerging aim of drug delivery requires the bioactive or therapeutic molecule to be protected from degradation and reach its target cell and intracellular location. Target specificity of nanoparticles is a prerequisite to attain the concentration of therapeutic agent required for therapeutic efficacy in the target tissue while minimising adverse effects on other parts of the body. Therefore, there is an urgent need for improvement of more effective drug delivery systems to direct the anticancer drugs to cancer cells, specifically. In the paper, we have described advantages of Lambda bacteriophage over other drug delivery vectors and proposed it as promising drug delivery vehicle. © 2012 Asian Network for Scientific Information.

Objective: Human papillomavirus (HPV) oncoproteins (i.e. E6 and E7) are constitutively expressed in cervical cancer cells. The proteins are ideal targets to be used for developing therapeutic vaccines against existing HPV-associated carcinomas. To date, whole bacteriophage (‘phage’)-λ particles, rather than purified ‘naked’ DNA, have been described as highly efficient delivery vehicles for a DNA vaccine. Methods: In this study, a safe and efficient λ-based therapeutic cancer vaccine, recombinant λ-ZAP E7 phage, was developed by inserting a HPV16 E7 gene into the Lambda ZAP® cytomegalovirus vector. λ-ZAP E7 phages were employed to immunize mice against the E7-expressing murine tumor cell line (TC-1), which is used as a tumor model in an H-2b murine system. Results: The tumor-bearing mice indicated a significant inhibition of tumor growth after 3 injections of 2 × 1012 particles of recombinant phages. Released lactate dehydrogenase, interferon-γ and granzyme B from spleen cells and lymphocyte proliferation of spleen cells, which all demonstrate the enhancement of cell-mediated immunity, suggested the phages could be a potent gene delivery system in animal models. Conclusion: Our results suggest the recombinant phages can be used as effective biological tools for inducing E7-specific protective immune responses. Hence, the study introduces a possible therapeutic strategy against cervical cancer and other HPV-related neoplasia.

Firefly luciferase catalyzes the oxidation of luciferin in the presence of ATP, Mg(2+) and molecular oxygen. The bioluminescence color of firefly luciferases is identified by the luciferase structure and assay conditions. Amongst different types of beetles, luciferase from Phrixotrix railroad worm (PhRE) with a unique additional residue (Arg353) naturally emits red bioluminescence color. By insertion of Arg356 in luciferase of Lampyris turkestanicus, corresponding to Arg353 in Phrixotrix hirtus, the color of the emitted light was changed to red. To understand the effect of this position on the bioluminescence color shift, four residues with similar sizes but different charges (Arg, Lys, Glu, and Gln) were inserted into Photinus pyralis luciferase. Comparison of mutants with native luciferase shows that mutation brought an increase in the content of secondary structure and globular compactness of (P. pylalis) luciferase. Comparative study of chemical denaturation of native and mutant luciferases by activity measurement, intrinsic and extrinsic fluorescence, circular dichroism, and DSC techniques revealed that insertion of positively charged residues (Arg, Lys) in the flexible loop (352-358) plays a significant role on the stability of (P. pyralis) luciferase and changes the light color to red.

This paper reviews the best known techniques using circular dichroism spectroscopy such as conventional circular dichroism (i.e. electronic circular dichroism), magnetic circular dichroisms (magnetic vibrational circular dichroism, x-ray magnetic circular dichroism), fluorescence detected circular dichroism, near-infrared circular dichroism, vibrational circular dichroism, Fourier transform infrared circular dichroism, high pressure liquid chromatography circular dichroism, stopped-flow circular dichroism, and synchrotron radiation circular dichroism. Also, we have described here the most important applications of circular dichroism spectroscopy in structural biochemistry and nanoscience.

Objective: During the latency period of herpes simplex virus type-1 (HSV-1), the virus can occasionally reactivate, travel back to the eye and cause recurrent ocular disease. As this condition arises from the ability of HSV-1 to produce a dormant infection, effective medication to prevent the virus enter a latent state should prevent it. In this study, we applied Echinacea polysaccharide (EP) fraction as prophylactic mediator for latency prevention. Methods: In order to investigate the protective properties of EP, we evaluated its immunostimulatory functions on different immune aspects that play important roles in latency prevention (particularly IFN-γ as one of the main indicators of cellular immunity and latency). Finally, we assessed establishment of latency by detection of thymidine kinase gene in trigeminal ganglia of BALB/c mice. Results: We demonstrated that EP promotes immune response, leading to a reduced latency rate, and it has a promising effect on latency prevention. Conclusion: EP was able to exert an antiviral action on the development of recurrent HSV-1 disease when supplied prior to infection.