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Recent studies demonstrated that the speed of synthesis, biocompatibility, and antimicrobial activity of gold (Au) and silver (Ag) metals is enhanced when biosynthesized in nano-sized particles. In the present study, Au- and Ag-based nanoparticles (NPs) were synthesized via a biological process using aqueous Ginger root extract and characterized by various spectroscopic methods. The NPs have hexagonal and spherical shapes. The average particle size for Au and Ag NPs was 20 and 15 nm, respectively. The dynamic light scattering (DLS) technique has shown that the zeta potential values of synthesized NPs were 4.8 and - 7.11 mv, respectively. Gas chromatography-mass spectrometry (GC-MS) analysis of Ginger root extract revealed 25 compounds. The synthesized NPs showed significant activity against Staphylococcus aureus and Escherichia (E). coli in vitro, with IC

Background: Preclinical and clinical studies show that local and systemic antitumor efficacy is achievable by in situ vaccination (ISV) using plant virus nanoparticles in which immunostimulatory reagents are directly administered into the tumor rather than systemically. Aim: To investigate a minimally studied plant virus nanoparticle, alfalfa mosaic virus (AMV), for ISV treatment of 4T1, the very aggressive and metastatic murine triple-negative breast cancer model. Materials & methods: AMV nanoparticles were propagated and characterized. Their treatment impact on in vivo tumors were analyzed using determination of inherent immunogenicity, cytokine analysis, western blotting analysis and immunohistochemistry methodologies. Results: AMV used as an ISV significantly slowed down tumor progression and prolonged survival through immune mechanisms (p

Purpose: This study aimed to design gentamicin-conjugated poly (amidoamine) (PAMAM) dendrimers to increase the therapeutic efficiency of gentamicin against Pseudomonas aeruginosa. Methods: Gentamicin-presenting dendrimers were synthesized using MAL-PEG3400-NHS as a redox-sensitive linker to attach gentamicin to the surface of G4 PAMAM dendrimers. The gentamicin molecules were thiolated by using Traut reagent. Then, the functionalized gentamicin molecules were attached to PEGylated PAMAM dendrimers through simple and high selectively maleimide (MAL)-thiol reaction. The structure of gentamicin-conjugated PAMAM dendrimers was characterized and confirmed using nuclear magnetic resonance (NMR), dynamic light scattering (DLS), zeta potential analysis, and transmission electron microscopy (TEM) imaging. The antibacterial properties of the synthesized complex were examined on P. aeruginosa and compared to gentamycin alone. Results: NMR, DLS, zeta potential analysis, and TEM imaging revealed the successful conjugation of gentamicin to PAMAM dendrimers. Data showed the appropriate physicochemical properties of the synthesized nanoparticles. We found a 3-fold increase in the antibacterial properties of gentamicin conjugated to the surface of PAMAM dendrimers compared to non-conjugated gentamicin. Based on data, the anti-biofilm effects of PAMAM-Gentamicin dendrimers increased at least 13 times more than the gentamicin in normal conditions. Conclusion: Data confirmed that PAMAM dendrimer harboring gentamicin could be touted as a novel smart drug delivery system in infectious conditions.

Background Carbapenem-resistant Enterobacteriaceae (CRE) is a major concern leading to morbidity and mortality in the world. CRE often is becoming a cause of therapeutic failure in both hospital and community-acquired infections. Aim This study aimed to investigate the resistance mechanisms of CRE by phenotypic and molecular methods. Materials and methods Sixty CRE (50 Klebsiella pneumoniae, 6 Escherichia coli, and 4 Enterobacter spp.) were isolated from October 2018 to June 2019. Antimicrobial susceptibility testing was carried out using phenotypic methods. The carbapenem resistance mechanisms including efflux pump hyperexpression, AmpC overproduction, carbapenemase genes, and deficiency in OmpK35 and OmpK36 were determined by phenotypic and molecular methods, respectively. Results Sixty CRE (50 Klebsiella pneumoniae, 6 Escherichia coli, and 4 Enterobacter spp.) were isolated from October 2018 to June 2019. Amikacin was found to be the most effective drug against CRE isolates. All isolates were resistant to imipenem and meropenem by the micro-broth dilution. AmpC overproduction was observed in all Enterobacter spp. and three K. pneumoniae isolates. No efflux pump activity was found. Carba NP test and Modified Hodge Test could find carbapenemase in 59 (98%) isolates and 57 (95%) isolates, respectively. The most common carbapenemase gene was bla OXA-48-like (72.8%) followed by bla NDM (50.8%), bla IMP (18.6%), bla VIM (11.8%), and bla KPC (6.7%). The ompK35 and ompK36 genes were not detected in 10 and 7 K. pneumoniae isolates, respectively. Conclusion The amikacin is considered as a very efficient antibiotic for the treatment of CRE isolates in our region. Carbapenemase production and overproduction of AmpC are the main carbapenem resistance mechanisms in CRE isolates. Finally, Carba NP test is a rapid and reliable test for early detection of carbapenemase-producing isolates.

Additional file 2. Supplementary file 2.

Bacterial nanocellulose (BNC) is a type of 3-dimensionally structured polymer gel produced by Acetobacter that has recently attracted increased interest in wound healing concerns. To produce an effective antibacterial wound dressing, researchers investigated the manufacturing and structural features of honey-infused BNC reinforced gelatin/aldehyde-modified Guar gum films (H/BNC/Ge/AD-GG). Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), mechanical characteristics, water solubility, and degradability were all used to assess the produced films. In addition, the influence of honey addition on the produced films' various properties has been examined. Antibacterial activity, better degradation capability, improved mechanical qualities, and excellent cell adhesion and proliferation by NIH-3T3 fibroblast cells were among the outcomes. The cytotoxicity assay in vitro revealed good cytocompatibility. As a result of the findings, the produced H/BNC/Ge/AD-GG films appear to have a high potential for antibacterial wound dressing applications.

Biocompatible hydrogels are promising approaches for bone repair and engineering. A novel therapeutic nanocomposite hydrogel was designed based on triblock copolymer poly e-caprolactone (PCL)-polyethylene glycol-PCL and natural gelatin (PCEC/GEL) and reinforced with halloysite nanotube (HNT). Gentamicin (GM) loaded HNT was immobilized in polymeric hydrogel matrix to fabricate scaffolds using the freeze-drying method. Scaffolds were characterized via Fourier transform infrared (FT-IR), x-ray powder diffraction, and scanning electron microscope (SEM) methods. The swelling ratio, density, porosity, degradation, and mechanical behavior were evaluated to investigate the effects of HNT on the physicochemical properties of the composite. Cell viability and cell attachment were investigated by microculture tetrazolium (MTT) assay and SEM. Cell proliferation was observed without any cytotoxicity effect on human dental pulp-derived mesenchymal stem cells (h-DPSCs). Alizarin red staining and real-time reverse transcription polymerase chain reaction (QRT-PCR) assay were carried out to monitor the osteoconductivity of scaffolds on h-DPSCs which were seeded drop wise onto the top of scaffolds. The quantification of the messenger RNA (mRNA) expression of osteogenic marker genes, bone morphogenetic protein 2, SPARK, bone gamma-carboxyglutamate protein and runt-related transcription factor 2 over a period of 21 d of cell seeding, demonstrated that cell-encapsulating PCEC/GEL/HNT-GM hydrogel scaffolds supported osteoblast differentiation of h-DPSCs into osteogenic cells through the up-regulation of related genes along with moderate effects on cell viability. Moreover, the antibiotics loading reduced bacterial growth while maintaining the osteogenic properties of the scaffold. Therefore, the bactericidal PCEC/GEL/HNT-GM hydrogel nanocomposite, with enhanced durability, maintenance the functionality of seeded cells in vitro that can be a remarkable dual-functional candidate for hard tissue reconstruction and customized bone implants fabrication via the direct incorporation of bactericidal drug to prevent infection.

Background:In late December 2019, a new infectious respiratory disease (COVID-19) was reported in a number of patients with a history of exposure to the Huanan seafood market in China. The World Health Organization officially announced the COVID-19 pandemic on March 11, 2020. Here, we provided an overview of the epidemiologic, diagnostic and treatment approaches associated with COVID-19.Methods:We reviewed the publications indexed in major biomedical databases by December 20, 2020 or earlier (updated on May 16, 2021). Search keywords included a combination of: COVID-19, Coronavirus disease 2019, SARS-CoV-2, Epidemiology, Prevention, Diagnosis, Vaccine, and Treatment. We also used available information about COVID-19 from valid sources such as WHO.Results and Conclusion:At the time of writing this review, while most of the countries authorized COVID-19 vaccines for emergency use starting December 8, 2020, there is no a definite cure for it. This review synthesizes current knowledge of virology, epidemiology, clinical symptoms, diagnostic approaches, common treatment strategies, novel potential therapeutic options for control and prevention of COVID-19 infection, available vaccines, public health and clinical implications.

Antibiotic resistance is one of the serious health-threatening issues globally, the control of which is indispensable for rapid diagnosis and treatment because of the high prevalence and risks of pathogenicity. Traditional and molecular techniques are relatively expensive, complex, and non-portable, requiring facilities, trained personnel, and high-tech laboratories. Widespread and timely-detection is vital to the better crisis management of rapidly spreading infective diseases, especially in low-tech regions and resource-limited settings. Hence, the need for inexpensive, fast, simple, mobile, and accessible point-of-care (POC) diagnostics is highly demanding. Among different biosensing methods, the isothermal amplification of nucleic acids is favorite due to their simplicity, high sensitivity/specificity, rapidity, and portability, all because they require a constant temperature to work. Isothermal amplification methods are utilized for detecting various targets, including DNA, RNA, cells, proteins, small molecules, ions, and viruses. In this paper, we discuss various platforms, applications, and potentials of isothermal amplification techniques for biosensing of antimicrobial resistance. We also evaluate the potential of these methods, coupled with the novel and rapidly-evolving platforms offered by nanotechnology and microfluidic devices.

From old times until nowadays, honey was applied to treat wounds due to its antibacterial and wound healing features. Honey as a carbohydrate-rich natural component could be applied directly in a clinical setting or incorporated into tissue-engineered platforms. The exploration of the antibiotic agent dramatically diminished its clinical application. However, there has been an increased requirement for alternative treatment approaches owing to the expansion in antibiotic resistance. Also, the physical features of honey make it hard to directly utilize it in an affected area. These limitations could be resolved by incorporating honey in a hydrogel formulation. Thanks to the anti-inflammatory capability of honey, its incorporation into hydrogels reduced the expression of the proinflammatory cytokines, attributing beneficial healing. Besides, in-vitro and in-vivo studies revealed that their administration significantly improved angiogenesis, reepithelialization, and granulation tissue formation. In this review, the overall antibacterial properties of honey, its current development in the design of honey-based hydrogels for wound healing (i.e., burns and diabetic ulcer healing), and the potential of honey-based tissue-engineered products will be comprehensively discussed.

Given the WHO report, resistance to antibacterial agents is responsible for the most deaths after car crashes every year. Thus, the development of new and more effective antibacterial classes is the main priority of the WHO. One of the most promising tools to tackle this problem is the designing and discovery of antibacterial peptides. Chensinin-1b is a modified analog of Chensinin-1, an antimicrobial peptide isolated from frog skin. The attachment of anti-bacterial peptides onto the surface of nanoparticles also enhanced their efficacy in synergistic manner. In this work, we functionalized the gold nanoparticles (GNPs) surface and evaluated the combinatorial effect of complex on the minimum inhibitory concentration (MIC) of the four pathogenic strains, including Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus, in the presence and absence of laser irradiation. The physicochemical properties of naked and peptide modified gold nanoparticles were evaluated by Dynamic light scattering (DLS), Transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FT-IR) methods. Also, the MIC of GNP, peptides and their the complex were analyzed on bacterial strains before and after photo-thermal therapy (PTT). Our results showed that the peptide has a more significant inhibitory effect on the bacteria compared to GNPs. Also, we illustrated that the GNP/peptide complex has synergistic antimicrobial effects compared to free GNP and peptide. Furthermore, we confirmed that photo-thermal therapy augmented the inhibitory effect of GNP and chensinin-1b modified GNPs against some strains. This study showed that the chensinin-1b modified GNPs in the presence or absence of PTT strongly suppress pathogenic bacteria.

A series of sila-organosulfur compounds containing 1,2,3-triazole cores were screened for their cytotoxic activity on human breast cancer cell line MCF-7. Most of the tested compounds exhibited moderate to good activity against the cancer cells. Especially, the compound 4-((2-(trimethylsilyl)ethynylthio)methyl)-1-benzyl-1H-1,2,3-triazole 3a from series of sila-substituted thioalkyne 1,2,3-triazoles (STATs) and the compounds 3-(1-Benzyl-1H-1,2,3-triazol-4-yl)-1-mercapto-1,1-bis(trimethylsilyl)propane-2-thione 4a and 1-Mercapto-1,1-bis(trimethylsilyl)-3-(1-phenethyl-1H-1,2,3-triazol-4-yl)propane-2-thione 4e from series of sila-substituted mercapto-thione 1,2,3-triazoles (SMTTs)exhibited promising cytotoxicity against MCF-7 with IC50 values of 35.17, 32.63 and 30.3 μg/mL, respectively. In addition, the possible mechanisms for inhibition of cell growth and induction of apoptotic cell death were explored by DAPI staining, cell cycle analysis and qRT-PCR. The synthetic compounds were evaluated for their in vitro anti-bacterial activities, and as a result the most prominent effects were observed for 3e and 4e. Especially, 3e was found to be quite active against all the tested strains with the MIC values ranging from 15 to 62 μg/mL, except P. aeruginosa. The results of the time-kill assay suggested that the compound of 3e completely inhibited the growth of both gram-negative bacteria A. baumannii and gram-positive bacteria S. aureus. In addition, SEM analysis confirmed morphostructural damage of the bacteria. Our findings could be applicable for developing dual targeting anti-cancer/anti-bacterial therapeutics. This article is protected by copyright. All rights reserved.

Piperacillin (Pip) is a broad spectrum β-lactam against most Gram-positive and Gram-negative aerobic and anaerobic bacteria. However, bacterial resistance restricts its benefits for the treatment of infectious diseases. Recently, nanoliposomal systems have been investigated as encouraging strategies to address this issue owing to their immense potential. We aimed to encapsulate Pip in liposomal nanoparticles and study their antibacterial activities in vitro against Pseudomonas aeruginosa (P. aeruginosa). Different liposomes were prepared based on the freeze-drying of a monophase solution method. Then, they were characterized in terms of size, zeta potential, polydispersity-index, and morphology. For further analysis, spectra of ATR-FTIR and XRD were taken for liposomal Pip. Encapsulation efficiency (EE) was determined via agar diffusion assay. Also, minimum inhibitory concentrations (MICs) were investigated by the standard broth macro-dilution method. The liposomes were from 100.9 to 444.13 nm with z-potential of − 30.70 to − 10.57 mV. EE of the selected formulation was 53.1%. TEM results showed that the liposomes were nanosized and almost spherical. ATR-FTIR results confirmed the full encapsulation of Pip in nanoliposomes. The X-ray pattern indicated that the liposomal Pip was amorphous. The MIC (10.6 µg/ml) of the nanoliposomal Pip against P. aeruginosa was one-half of the MIC (21.25 µg/ml) of free Pip for the same organisms. Considering four aspects (nanosized liposomes, no need for sterilization, suitable EE and enhanced antibacterial effects), this preparation method seems promising and may be used to overcome the bacterial resistance relative to Pip.

Nanoparticles have unique capabilities and considerable promise for many different biological uses. One capability is delivering bioactive cargos to specific cells, tissues, or organisms. Depending on the task, there are multiple variables to consider including nanoparticle selection, targeting strategies, and incorporating cargo so it can be delivered in a biologically active form. One nanoparticle option, genetically controlled plant viral nanoparticles (PVNPs), is highly uniform within a given virus but quite variable between viruses with a broad range of useful properties. PVNPs are flexible and versatile tools for incorporating and delivering a wide range of small or large molecule cargos. Furthermore, PVNPs can be modified to create nanostructures that can solve problems in medical, environmental, and basic research. This review discusses the currently available techniques for delivering bioactive cargos with PVNPs and potential cargos that can be delivered with these strategies. This article is categorized under: Implantable Materials and Surgical Technologies > Nanomaterials and Implants Biology-Inspired Nanomaterials > Protein and Virus-Based Structures.

Graphical abstract, Highlights • MERS-CoV, SARS-CoV-1/2 as members of β-CoVs family have many similar pathogenicity. • Frequency of emerging β-CoVs infections reported in males are higher than females. • Sex-hormones and X-chromosome related genes may be the cause of these sex differences. • Immune response of women might protect further against MERS, SARS-CoV1/2 infections. • Sex-based immune-responses may provide new insights for upcoming immunotherapies., Emerging beta-coronaviruses (β-CoVs), including Severe Acute Respiratory Syndrome CoV-1 (SARS-CoV-1), Middle East Respiratory Syndrome-CoV (MERS-CoV), and Severe Acute Respiratory Syndrome CoV-2 (SARS-CoV-2, the cause of COVID19) are responsible for acute respiratory illnesses in human. The epidemiological features of the SARS, MERS, and new COVID-19 have revealed sex-dependent variations in the infection, frequency, treatment, and fatality rates of these syndromes. Females are likely less susceptible to viral infections, perhaps due to their steroid hormone levels, the impact of X-linked genes, and the sex-based immune responses. Although mostly inactive, the X chromosome makes the female's immune system more robust. The extra immune-regulatory genes of the X chromosome are associated with lower levels of viral load and decreased infection rate. Moreover, a higher titer of the antibodies and their longer blood circulation half-life are involved in a more durable immune protection in females. The activation rate of the immune cells and the production of TLR7 and IFN are more prominent in females. Although the bi-allelic expression of the immune regulatory genes can sometimes lead to autoimmune reactions, the higher titer of TLR7 in females is further associated with a stronger anti-viral immune response. Considering these sex-related differences and the similarities between the SARS, MERS, and COVID-19, we will discuss them in immune responses against the β-CoVs-associated syndromes. We aim to provide information on sex-based disease susceptibility and response. A better understanding of the evasion strategies of pathogens and the host immune responses can provide worthful insights into immunotherapy, and vaccine development approaches.

The antimicrobial property of silver is associated to the quantity of silver and the grade of silver released. The ionized silver is extremely sensitive, as it binds to tissue proteins and gets operational alterations in the bacterial cell wall and nuclear membrane leading to cell modification and death.Silver nanoparticles have the talent to anchor to the bacterial cell wall and consequently infiltrate it, so causing physical modifications in the cell membrane like the absorptivity of the cell membrane and death of the cell. There are numerous concepts on the act of silver nanoparticle on bacteria to reason the microbicidal influence.

Background:Helicobacter pylori is a prevalent pathogen which is considered as an etiological cause for gastroduodenal ulcers, and a substantial risk factor for gastric malignancies. The vital factor to take into account is that roughly half of the world's population is infected with this bacterium. However, most subjects colonized remain asymptomatic and do not require any treatment. Several antimicrobial agents such as amoxicillin, clarithromycin and metronidazole are used to eradicate the infection. However, these drug regiments do not eradicate H. pylori in all patients because of the anti-drug resistance. Aim: In this review we aim to discuss the role and mechanisms of probiotics, as supportive medicines, in management of H. pylori infection. Methods: We have reviewed the published articles in PubMed and Medline databases. Also, abstracts presented in international conferences on the management of H. pylori infections and treatment protocol, have been thoroughly reviewed. Results: The overall trend in the literature indicates the usefulness of probiotics in controlling H. pylori infection. This bacterium is among the most studied human pathogens regarding the efficacy of probiotics for treating its infection. Nevertheless, some studies suggest that probiotics do not efficiently eradicate H. pylori but retain the number of this bacterium at low levels inside the human stomach. Conclusion: The analyzed literature suggest that when probiotics are consumed in conjunction with antibiotics, the eradication rate may be improved through modulating the immune response and decreasing the adverse effects of routine drugs leading to gastroprotection.

Purpose: Clofarabine, a purine nucleoside analogue and inhibitor of Ribonucleotide Reductase (RR), is used for treatment of leukemia. Clofarabine-induced defect in DNA replication, induces p53 and subsequently P53R2 genes as subunit of RR. clofarabine deregulated P53R2 gene expression leading to the elevated levels of P53R2 which impose resistance to DNA damaging drugs. In this study the apoptotic and cytotoxic effects of clofarabine has been investigated on breast cancer cell line. Methods: Cofarabine cytotoxicity on T47D cells has been studied by MTT assay. T47D cells were exposed to the different concentrations of clofarabine for 24, 48 and 72 hours intervals. Relative expression of P53R2 gene has been studied using real-time PCR. Moreover, after treating with clofarabine the apoptotic and necrotic cells were detected using Annexin V and propodium iodide (PI) reagents by flowcytometry technique. Results: MTT assay results showed that the clofarabine IC50 on T47D cell line were 3 and 2.5µM after 48 and 72 h exposure, respectively. Clofarabine did not show any significant cytotoxic effect after 24 h exposure. The analysis of qRT-PCR showed a significant increase in P53R2 gene expression in treated cells with both 2.5 and 3 μM doses and also, the results of flowcytometry revealed 26.91 and 74.46 percent apoptosis induction in 48 and 72h treatments respectively in comparison to the control groups. Conclusion: Our results showed that apoptotic and cytotoxic effects of clofarabine on T47D cell line were in time and dose dependent manner; therefore it could be considered a new candidate in breast cancer therapy.

The objectives of the study were to isolate and characterize the bacteriocin producing enterococci in 30 enterococcal poultry isolates from north-west of Iran and to determine the prevalence of bacteriocin structural genes among them. Methods: The obtained isolates were assessed for antibacterial action against 6 indicator strains. The PCR method was applied to detect previously identified enterocin genes. Results: Based on our results 4 (13.3%) of the examined poultry enterococcal isolates were considered as potential bacteriocinogenic strains, all of them identified to be Enterococcus faecium via phenotypic and genotypic examinations. At least one of the detected Bac+ isolates had antibacterial activities against Bacillus cereus, Listeria monocytogenes, Enterococcus faecalis and Enterococcus hirea with no activity against Escherichia coli or Staphylococcus aureus. Conclusion: Genes encoding Enterocin A and enterocin LA50A/B are fairly distributed among the studied poultry enterococci.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common organisms isolated from clinical samples, and has been associated with morbidity and mortality among hospitalized patients. The aim of this study was to evaluate the prevalence and antibiotic susceptibility patterns among MRSA and methicillin-sensitive S. aureus (MSSA) isolates collected from four hospitals in Iran.A total of 183 isolates of S. aureus were collected from various clinical specimens of four hospitals in Iran. The isolates were identified by using the conventional biochemical tests. Three methods-oxacillin agar disk diffusion, oxacillin agar screening, and PCR- were applied to determine susceptibility to oxacillin. The conventional disk agar diffusion test was used to evaluate the antibiotic sensitivity of our isolates against 15 antibiotics, according to the guidelines of the Clinical and Laboratory Standards Institute (CLSI).Of 183 isolates, 77 isolates (42.1%) were found to be MRSA, by the PCR method. The highest antibiotic resistance was found to be against penicillin, co-trimoxazole, erythromycin, and tetracycline respectively. All isolates were susceptible to vancomycin, according to the results of disk agar diffusion. Among other antibiotics, teicoplanin (84%) and fusidic acid (80.5%) were more active against MRSA isolates. For the different methods evaluated, the sensitivities and specificities were as follows: for disk agar diffusion (84.9% and 95.9%) and for agar screening test with oxacillin concentrations of 0.6 μg/ml (70.8% and 97.4%), 4 μg/ml (96.1%and 97.2%) and 6 μg/ml (96% and 96.3%), respectively.The results of our study showed that 47% of S. aureus isolates were MRSA. Overall, in this research study, resistance to all test antimicrobial agents in MRSA isolates were higher than that of MSSA isolates. Our results also revealed that 85% of mecA-positive isolates and 15% of mecA-negative isolates were resistant to methicillin; while 96% of mecA-negative isolates were sensitive to methicillin. Meanwhile 4% of mecA-positive isolates were also sensitive to methicillin.

Gene therapy is defined as the direct transfer of genetic material to tissues or cells for the treatment of inherited disorders and acquired diseases. For gene delivery, magnetic nanoparticles (MNPs) are typically combined with a delivery platform to encapsulate the gene, and promote cell uptake. Delivery technologies that have been used with MNPs contain polymeric, viral, as well as non-viral platforms. In this review, we focus on targeted gene delivery using MNPs.

Background: Tetracycline is an antibiotic widely used for the treatment of Helicobacter pylori infection, but its effectiveness is decreasing due to increasing bacterial resistance. The aim of this study was to investigate the occurrence of 16S rRNA mutations associated with resistance or reduced susceptibility to tetracycline ofHelicobacter pylori by real-time PCR (RT-PCR) assays from culture. Materials and Methods: Tetracycline susceptibility and minimal inhibition concentration (MIC) was determined by the Epsilometer test (Etest) method. A LightCycler assay developed to detect these mutations was applied to DNA extracted from culture. The 16S rRNA of these isolates was sequenced and resistance-associated mutations were identified. From 104 isolates of H. pylori examined, 11 showed resistance to tetracycline. Results: LightCycler assay was applied to DNA extracted from 11 tetracycline-susceptible and 11 tetracycline resistance H. pylori isolates. In our study the sequencing of the H. pylori wild types in 16 s rRNA gene were AGA 926-928 with MIC (0.016 to 0.5µg/ml), while the sequencing and MIC for resistant were GGA and AGC, (0.75 to 1.5µg/ml), respectively. Also we found a novel mutation in 2 strains with 84°C as their melting temperatures and exhibition of an A939C mutation. Conclusions: We conclude that real-time PCR is an excellent method for determination of H. pylori tetracycline resistance related mutations that could be used directly on biopsy specimens.

Trigonella foenum-graecum generally known as fenugreek, has been normally cultivated in Asia and Africa for the edible and medicinal values of its seeds. Fenugreek leaves and seeds have been used widely for therapeutic purposes. Fenugreek seed is recognized to show anti-diabetic and anti-nociceptive properties and other things such as hypocholesterolaemic, and anti-cancer. Diosgenin is a steroidal saponin from therapeutic herbs, fenugreek (T. foenum-graceum L.), has been well-known to have anticancer properties. Telomerase activity is not identified in usual healthy cells, while in carcinogenic cell telomerase expression is reactivated. Therefore telomerase illustrates a promising cancer therapeutic target. We deliberate the inhibitory effect of pure diosgenin and fenugreek extract diosgenin on human telomerase reverse transcriptase gene (hTERT) expression which is critical for telomerase activity. MTT-assay and qRT-PCR analysis were achieved to discover cytotoxicity effects and hTERT gene expression inhibition properties, separately. MTT results exhibited that IC50 for pure diosgenin were 47, 44 and 43 µM and for fenugreek extract diosgenin were 49, 48 and 47 µM for 24, 48 and 72 h after treatment. Culturing cells with pure diosgenin and fenugreek extract diosgenin treatment caused in down regulation of hTERT expression. These results indication that pure and impure diosgenin prevents telomerase activity by down regulation of the hTERT gene expression in A549 lung cancer cell line, with the difference that pure compound is more effective than another.

Silver nanoparticles size makes wide range of new applications in various fields of industry. Synthesis of noble metal nanoparticles for applications such as catalysis, electronics, optics, environmental and biotechnology is an area of constant interest. Two main methods for Silver nanoparticles are the physical and chemical methods. The problem with these methods is absorption of toxic substances onto them. Green synthesis approaches overcome this limitation. Silver nanoparticles size makes wide range of new applications in various fields of industry. This article summarizes exclusively scalable techniques and focuses on strengths, respectively, limitations with respect to the biomedical applicability and regulatory requirements concerning silver nanoparticles.

The aim of this study was to develop a novel nanofiber-based structure to sustain the antibacterial effect of plant essential oils during a storage period in order to be used in active packaging applications. To this end, cinnamon essential oil nanophytosome (N/CEO) was prepared and embedded into cross-linked polyvinyl alcohol nanofiber (PVAc-N/CEO) using the electrospinning technique. The physicochemical characteristics and morphology of the nanofibers were evaluated by tensile, water vapor permeability, ATR-FTIR, TGA, and SEM analyses. Also, the cell toxicity and antibacterial effect of nanofibers were investigated. Finally, the antibacterial effect was validated on raw shrimp as a food model for 7 days storage. The results indicated that the N/CEO was successfully embedded into nanofiber matrix. In addition, PVAc-N/CEO, showed low cell toxicity, strong antibacterial effects and extension of shelf-life of shrimp compared to cross-linked PVA nanofiber containing CEO (PVAc/CEO). The results showed that the PVAc-N/CEO nanofiber has great potential in active packaging applications for shelf-life extension of perishable food products.

Background & aims Increasing antibiotic resistance among Helicobacter pylori isolates and the unsuccessful attempts at eradication can impose many costs to both healthcare systems and patients. The present study intended to find a way from which H. pylori could be isolated from biopsies with less invasive procedures undertaken on infected patients. Methods A biopsy specimen from each patient with gastric disorders was put into urea-containing agar. After two hours, the specimens were removed from agar and placed into tubes containing 1 ml 20% glucose solution. Then, the specimens were inoculated onto the Columbia agar and incubated under microaerophilic conditions. The grown colonies were identified as H.pylori based on the microbiology tests and PCR. Results Overall, 449 biopsy specimens were collected from the patients. Of all biopsies, 219 (48.8%) revealed positive results in the rapid urease test. Using the aforementioned method, 158 (35.2%) culture positive biopsy specimens were obtained. Conclusion The researchers attempted to use one biopsy specimen for both rapid urease and culture tests. This method causes fewer injuries of gastric tissue and allows antimicrobial susceptibility testing and characterization in detail of the isolated organism.

Diagnosis and treatment of lung cancer have been characterized with a variety of challenges. However, with the advancement in magnetic nanoparticle (MNP) technology, many challenges in the diagnosis and treatment of lung cancer are on the decline. The MNPs have led to many break-through in cancer therapy. This paper seeks to establish the role of MNPs in diagnosis and treatment of lung cancer. It proposes that the existing challenges in the diagnosis and treatment of lung cancer can be addressed through application of MNPs in the process.

Nowadays the control of multidrug resistant (MDR) and pandrug resistant (PDR) bacteria has been the subject of extensive research. In this study an effective strategy was developed to destroy bacteria using low-level laser photothermal therapy combined with biocompatible surface-modified AuNPs. First, chitosan, poly(N-isopropylacrylamide)-co-(2-dimethylamino ethyl methacrylate) P(NIPAAM-co-DMAEMA) and poly(lactic-co-glycolic acid) (PLGA) modified AuNPs were synthesized and fully characterized. Afterwards, P. aeruginosa and A. baumannii (Two Gram-negative strains of bacteria) were exposed to different doses of low level NIR laser (810 nm) radiation in the presence or absence of the as-prepared surface-modified AuNPs (in a 1:1 ratio) and the killing efficiency of the radiated laser doses was calculated based on pour-plate colony count for each condition. Chitosan, P(NIPAAM-co-DMAEMA) and PLGA modified AuNPs were synthesized with a core/shell size of 108, 10 and 120 nm, respectively which was confirmed with DLS and TEM studies. Successful polymerization and surface coating of AuNPs was confirmed by FT-IR and 1H NMR. A decreasing trend in the viability of both bacteria was observed along with an increase of the laser dose for all three types of polymer-coated AuNPs. PLGA@AuNPs exhibited the most effective NIR-induced photothermal killing on both bacteria. In other words, 10 J cm-2 and 30 J cm-2 doses were enough to destroy almost all P. aeruginosa, and A. baumannii, respectively. Our study suggests the usefulness of low-level laser in plasmonic photothermal treatment. The suggested strategy, as a new method of anti-bacterial intervention, can be used for the eradication of infections such as wound infections in order to accelerate the healing process. In addition, the offered strategy can be suggested in the treatment of other bio-threats such as cancerous diseases in vivo. Refereed/Peer-reviewed

Recent data indicates an increasing rate of vancomycin resistance in clinical enterococcal isolates worldwide. The nosocomial enterococci are likely to harbor virulence elements that increase their ability to colonize hospitalized patients. The aim of this study was to characterize virulence determinants in vancomycin-resistant enterococci (VRE) obtained from various clinical sources. During the years 2008 to 2010, a total of 48 VRE isolates were obtained from three University teaching hospitals in Northwest, Iran. Initially, phenotypic speciation was done and minimum inhibitory concentrations (MICs) of vancomycin were determined by agar dilution method and E-test. Then, species identification and resistance genotypes along with detection of virulence genes (asa1, esp, gelE, ace and cpd) of the isolates were performed by multiplex PCR. Thirty eight isolates were identified as vancomycin-resistant Enterococcus faecium (VREfm) and ten as E. faecalis (VREfs). Irrespective of the species, vanA gene (89.58%) was dominant and three phenotypically vancomycin susceptible E. faecium isolates carried the vanB gene. Among virulence genes investigated, the esp was found in 27(71%) VREfm strains, but did not in any VREfs. Other virulence determinants were highly detected in VREfs strains. Our data indicate a high prevalence of E. faecium harboring vancomycin resistance with vanA genotype and the two VRE species displayed different virulence genes.

Objectives: Surface attributes of a restoration play an important role in adherence of plaque bacteria. Prophylaxis methods may be involved in modification of or damaging the restoration surface. The aim of the present study was to evaluate the effect of two prophylaxis methods on adherence of Streptococcus mutans to the surface of two restorative materials. Study design: A total of 60 specimens were prepared from each material; a microfilled composite resin (HelioProgress) and a giomer (Beautifil II). For each material, the specimens were randomly divided into three groups (n=20). Group 1: no prophylaxis treatment (control); Group 2: prophylaxis with pumice and rubber cup; Group 3: prophylaxis with air-powder polishing device (APD). The surfaces of selected specimens from each group were evaluated under a scanning electron microscope (SEM), and the surface topography formed by the two prophylaxis methods was determined by atomic force microscopy (AFM). Adherence of Streptococcus mutans to the surface of specimens was determined by the plate counting method following immersion in a bacterial innoculum for 4 hours, rinsing and sonication. Data were analyzed by two-way ANOVA and post hoc Tukey test for multiple comparisons. Statistical significance was set at P

The objective of the present research was to formulate poly(lactide-co-glycolide) nanoparticles loaded with azithromycin with appropriate physicochemical properties and antimicrobial activity. Azithromycin-loaded poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) were prepared in three different ratios of drug to polymer by nanoprecipitation technique. Antibacterial activity of these nanoparticles was examined against gram-negative intra cellular microorganism Salmonella typhi. The antibacterial effect was investigated using serial dilution technique to achieve the minimum inhibitory concentration (MIC) of nanoparticles. The results showed that physicochemical properties were affected by drug to polymer ratio. The results showed that nanoscale size particles ranging from 212 to 252nm were achieved. Physicochemical properties were affected by drug to polymer ratio. The highest entrapment efficiency (78.5+/-4.2%) was obtained when the ratio of drug to polymer was 1:3. Zeta (zeta) potential of the nanoparticles was fairly negative. The DSC thermograms and X-ray diffraction patterns revealed that the drug in the nanoparticles was in amorphous state. FT-IR spectroscopy demonstrated no detectable interactions between the drug and polymer in molecular level. In vitro release study showed two phases: an initial burst for 4h followed by a very slow release pattern during a period of 24h. The results of antimicrobial activity test showed that the nanoparticles were more effective than pure azithromycin against S. typhi with the nanoparticles showing equal antibacterial effect at 1/8 concentration of the intact drug. In conclusion, the azithromycin nanoparticle preparations showed appropriate physicochemical and improved antimicrobial properties which can be useful for oral administration.

Rapid and sensitive detection techniques for indicator pathogens are important in pharmaceutical industry. However, common detection methods rely on bacterial culture in combination with biochemical tests, a process that typically takes 5–6 days to complete. Thus, the aim of this study was to develop a multiplex polymerase chain reaction (mPCR) assay for simultaneous detection and identification of four indicator pathogenic bacteria in a single reaction. Specific primers for indicator bacteria, namely Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosaand Salmonella, were applied to allow simultaneous detection of them, and the sensitivity and specificity of each primer pairs were determined. In the mPCR with mixed DNA samples, specific bands for corresponding bacteria were simultaneously detected. Agarose gel electrophoresis of PCR products revealed 100% specificity of mPCR with single bands in the expected sizes. Low levels of microbial contamination less than 10 cfu per milliliter or gram of product were detected using mPCR assay. The detection of all four indicator pathogenic bacteria were completed in less than 8 h with this novel mPCR method, whereas the conventional United States Pharmacopeia methods and uniplex PCR required 5–6 days and 27 h for completion, respectively. Using mPCR assay, the microbial quality control of nonsterile pharmaceutical products can be performed in a cost-effective and timely manner in pharmaceutical industry. PRACTICAL APPLICATIONS Detection of pathogenic indicatiors of Escherichia coli, Staphylococcus aureus, Salmonella and Pseudomonas aeruginosa is one of the mandatory tests in microbial quality of nonsterile pharmaceutical products; therefore, rapid and sensitive detection of the contaminations is of great importance for product release. According to the results of the present study, simultaneous detection of low levels of four major potential pathogenic bacteria in pharmaceutical finished products can be performed using mPCR in a cost-effective and timely manner, and upon these properties of the mPCR assay it could have potential applications in pharmaceutical industry.

Clarithromycin (CLR) formulation was prepared as PLGA nanoparticles in order to enhance the therapeutic effects using the distinctive features of a nanoparticulate delivery system. CLR loaded PLGA nanoparticles were prepared by Quasi Emulsion Solvent Diffusion (QESD) method using Poly lactic-co-Glycolic Acid (PLGA) as a biodegradable polymer. Antibacterial activity of the prepared formulations was evaluated against clinical strains of Helicobacter pylori, isolated from gastric biopsies of patients with gastritis, duodenal ulcer, peptic ulcer, and gastroesophageal reflux disease undergoing endoscopy, by using agar dilution method.Spherical nanoparticles with relatively narrow size distribution (between 200 and 800 nm) in the size range of 305 ± 138, 344 ± 148 and 362 ± 110 nm were achieved for F22, F23 and F23 respectively. CLR encapsulation percentages were measured to be 57.4 ± 4.3 to 80.2 ± 4.0%. CLR loaded PLGA nanoparticles showed equal or enhanced eradication effect against H. pylori strains according to the declined MIC values in comparison with the untreated CLR.In conclusion, the prepared CLR nanoformulation showed appropriate physicochemical properties and improved activity against H. pylori that could be a suitable candidate for oral preparations.

Helicobacter pylori infection is very common worldwide and is an important cause of gastritis, peptic ulcer disease, gastric mucosa-associated lymphoid tissue lymphoma, and gastric adenocarcinoma. Since the eradication requires treatment with multidrug regimens, prevention of primary infection by a suitable vaccine is attractive. Developing vaccines on the spot when and where an infection is breaking out might be possible, thanks to engineered nanoparticles. In this review, the nature of the host immune response to H. pylori infection is considered. We explain recent candidate vaccines and prophylactic or therapeutic immunization strategies for use against H. pylori. We also describe identification of different types of immune responses that may be related to protection against H. pylori infection. Thus, it seems that there is still a strong need to clarify the main protective immune response against H. pylori.

Metal nanoparticles, such as nanoparticles synthesized using gold, have numerous uncommon chemical and physical properties due to the effects of their quantum size and their large surface area, in comparison with other metal atoms or bulk metal. Gold nanoparticles (GNPs), in particular, are very attractive because of their size and shape-dependent properties. Metal nanoparticles have gathered extensive attention due to their uncommon properties and promising applications in photonics, electronics, biochemical sensing, and imaging. This review covers recent advances in the synthesis of GNPs.

Breast cancer is the most commonly diagnosed cancer and the leading cause of cancer death among women worldwide. Herbal medicines have tremendous potential as promising agents for the treatment of cancer. Curcumin is a natural polyphenol which has many anticancer effects. Because of its low aqueous solubility, low bioavailability, and quick degradation and metabolism, curcumin was released using PLGA-PEG nanoparticles. Herein, the efficiency of pure curcumin and curcumin-loaded PLGA-PEG in MCF-7 human breast cancer cell lines was studied. (1)H NMR, FT-IR and SEM demonstrated PLGA-PEG structure and curcumin loaded on nanoparticles. Subsequently, the cytotoxic effects of free curcumin and curcumin-loaded PLGA-PEG were determined via an MTT assay. Our study confirmed that curcumin-loaded PLGA-PEG has more cytotoxic effects on the MCF-7 breast cancer cell line and could be exploited as a potential source for developing novel drugs against breast cancer.

The properties of graphene, carbon sheets that are only one atom wide, have led researchers and companies to consider its synthesis, properties, and the applications in numerous fields. High-quality graphene is physically powerful, light, nearly transparent, and an exceptional conductor of heat and electricity. Its interactions with other materials and with light and its naturally two-dimensional nature produce unique properties, such as the bipolar transistor effect, ballistic transport of charges, and large quantum oscillations. The following review introduces the many potential applications of graphene.