Evaluation of an antibacterial peptide-loaded amniotic membrane/silk fibroin electrospun nanofiber in wound healing.

Antimicrobial peptides (AMPs) are among the compounds that have significant potential to deal with infectious skin wounds. Using wound dressings or skin scaffolds containing AMPs can be an effective way to overcome infections caused by antibiotic-resistant strains. In this study, we developed an amniotic membrane-based skin scaffold using silk fibroin to improve mechanical properties and CM11 peptide as an antimicrobial peptide. The peptide was coated on the scaffold using the soaking method. The fabricated scaffold was characterised by SEM and FTIR, and their mechanical strength, biodegradation, peptide release, and cell cytotoxicity analyses were performed. Then, their antimicrobial activity was measured against antibiotic-resistant strains of Pseudomonas aeruginosa and Staphylococcus aureus. The in vivo biocompatibility of this scaffold was evaluated by subcutaneously implanting it under the skin of the mouse and counting lymphocytes and macrophages in the implanted area. Finally, the regenerative ability of the scaffold was analyzed in the mouse full-thickness wound model by measuring the wound diameter, H&E staining, and examining the expression rate of genes involved in the wound healing process. The developed scaffolds exerted an inhibiting effect on the bacteria growth, indicating their proper antimicrobial property. In vivo biocompatibility results showed no significant count of macrophages and lymphocytes between the test and control groups. The wound closure rate was significantly higher in the wound covered with fibroin electrospun-amniotic membrane loaded with 32 µg/mL CM11, where the relative expression rates of collagen I, collagen III, TGF-ß1 and TGF-ß3 were higher compared with the other groups.

Immunosenescence and inflamm-ageing in COVID-19.

The destructive effects of coronavirus disease 2019 (COVID-19) on the elderly and people with cardiovascular disease have been proven. New findings shed light on the role of aging pathways on life span and health age. New therapies that focus on aging-related pathways may positively impact the treatment of this acute respiratory infection. Using new therapies that boost the level of the immune system can support the elderly with co-morbidities against the acute form of COVID-19. This article discusses the effect of the aging immune system against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the pathways affecting this severity of infection.

Rapamycin attenuates gene expression of programmed cell death protein-ligand 1 and Foxp3 in the brain; a novel mechanism proposed for immunotherapy in the brain.

BACKGROUND AND PURPOSE: Programmed cell death protein-1 (PD1) expresses on the cell surface of the activated lymphocytes and at least a subset of Foxp3+ regulatory T cells. The binding of PD1 to its ligands including PD-L1 and PD-L2 leads to deliver an inhibitory signal to the activated cells. Although PD1/PD-L signal deficiency can lead to failure in the self-tolerance and development of autoimmunity disorders, PD1 blockade with monoclonal antibodies is considered an effective strategy in cancer immunotherapy. Determining effective environmental factors such as stress conditions on the expression of PD1 and PD-L1 genes can provide an immunotherapeutic strategy to control PD1 signaling in the patients Mammalian target of rapamycin signaling is a stress-responsive pathway in the cells that can be blocked by rapamycin. In this study, the effects of rapamycin on the expression of immunoregulatory genes were investigated in the stress condition. EXPERIMENTAL APPROACH: Daily administration of rapamycin (1.5 mg/kg per day) was used in the mouse model of restraint stress and the relative expression of PD1, PD-L1, and Foxp3 genes in the brain and spleen were evaluated using quantitative real-time polymerase chain reaction method. FINDINGS/RESULTS: With our observation, daily restraint stress ceased rapamycin to decrease the expression of Foxp3 in the brain significantly. These findings would be beneficial in developing tolerance to autoimmune diseases and finding immunopathology of stress in the CNS. In another observation, daily administration of rapamycin decreased the expression of PD-L1 in the brain cells of mice. In the spleen samples, significant alteration in genes of interest expression was not detected for all groups of the study. CONCLUSION AND IMPLICATIONS: Downregulation of the PD-L1 gene in the brain induced by rapamycin can be followed in future experiences for preventing immunosuppressive effects of PD/PD-L1 signal in the brain.

Clinical characteristics and outcome of hospitalized COVID-19 patients with diabetes: A single-center, retrospective study in Iran.

AIM: To describe the epidemiological and clinical characteristics along with outcomes of hospitalized Coronavirus Disease 2019 (COVID-19) patients with and without diabetes. METHODS: This retrospective, single-center study included 595 consecutive hospitalized patients with confirmed COVID-19 at Baqiyatallah Hospital in Tehran, Iran, from February 26, 2020 to March 26, 2020. Demographic data, clinical, laboratory, and radiological findings were collected and compared between patients based on diabetes status. Complications and clinical outcomes were followed up until April 4, 2020. RESULTS: From among the 595 hospitalized patients with COVID-19, the median age was 55 years and 401 (67.4%) were male. The most common symptoms included fever (419 [70.4%]), dry cough (368 [61.8%]) and dyspnea (363 [61%]). A total of 148 patients (24.9%) had diabetes, and compared with patients without diabetes, these patients had more comorbidities (eg, hypertension [48.6% vs. 22.3%; P < 0.001]); had higher levels of white blood cell count, neutrophil count, C-reactive protein, erythrocyte sedimentation rate and blood urea nitrogen, and had a higher proportion of patchy ground-glass opacity in chest computed tomography findings (52.7% vs. 25.7%; P < 0.001). Significantly, patients with diabetes had more complications and needed more respiratory support than those without diabetes (P < 0.001). At the end of the follow-up, treatment failure and death was significantly higher in patients with diabetes compared to those without diabetes (17.8% vs. 8.7%; P = 0.003). CONCLUSION: COVID-19 patients with diabetes are at a higher risk of complications and a higher in-hospital mortality during hospitalization. Diabetes status of COVID-19 patients and frequent monitoring of glycemia would be helpful to prevent deteriorating clinical conditions.

Developing a DNA aptamer-based approach for biosensing cystatin-c in serum: An alternative to antibody-based methods.

Oligonucleotide aptamers are short, synthetic and single-stranded DNA or RNA molecules capable of binding to a wide range of molecules, from small molecules to large cells. Nowadays, aptamers are valuable tools in research, clinical diagnosis and treatment. Their small size and high specificity in addition to their lack of immunogenicity make them great alternatives to other diagnosing candidates such as antibodies. In this study, we have introduced a new method based on competitive Enzyme-Linked Aptamer Sorbent Assay (ELASA) using single-stranded DNA (ssDNA) aptamers to measure cystatin-c levels in serum samples. To this aim, through a Systematic Evolution of Ligands by Exponential Enrichment (SELEX) process a number of aptamers were selected from which an aptamer with a Kd (dissociation constant) value of 65.5 ±â€¯0.007 nM was chosen for further analyses. The limit of detection (LoD) was found to be 216.077 pg/ml. The results of the analytical application of this method in serum samples were comparable to those of commonly used commercial kits.

Evaluation and statistical optimization of a method for methylated cell-free fetal DNA extraction from maternal plasma.

PURPOSE: Methylated cell-free fetal DNA (cffDNA) in maternal plasma can potentially be used as a biomarker for accurate noninvasive prenatal testing (NIPT) of fetal disorders. Recovery and purification of cffDNA are key steps for downstream applications. In this study, we aimed to developed and evaluated different aspects of an optimized method and compared its efficiency with common methods used for extraction of methylated cffDNA. METHODS: Single factor experiments, Plackett-Burman (PB) design, and response surface methodology (RSM) were conducted for conventional Triton/Heat/Phenol (cTHP) method optimization. The total cell-free DNA (cfDNA) was extracted from pooled maternal plasma using the optimized method called the Triton/Heat/Phenol/Glycogen (THPG), cTHP method, a column-based kit, and a magnetic bead-based kit. In the next step, methylated cfDNA from the extracted total cfDNA was enriched using a methylated DNA immunoprecipitation (MeDIP) kit. Real-time quantitative polymerase chain reaction was performed on the RASSF1 gene and hyper region to determine the genomic equivalents per milliliter (GEq/ml) values of the methylated cfDNA and cffDNA, respectively. RESULTS: The optimum values of the significant factors affecting cfDNA extraction from 200 µl of plasma were 3% SDS, 1% Triton X-100, 0.9 µg/µl glycogen, and 0.3 M sodium acetate. The GEq/ml values of methylated cffDNA extracted using the THPG method were significantly higher than for the tested extraction methods (p < 0.001). CONCLUSIONS: Our results indicate that the THPG method is more efficient than the other tested methods for extraction of low copy number methylated cffDNA from a small volume of maternal plasma.

Electrospun Schizophyllan/polyvinyl alcohol blend nanofibrous scaffold as potential wound healing.

In this study, aqueous Schizophyllan (SPG) (1.5 w/v%) was mixed with aqueous polyvinyl alcohol (PVA) (10 w/v%) at various volume ratios and electrospun to prepare nanofibers. The fiber diameter was decreased by increasing the SPG content. A reliable linear relationship (p < 0.01) was established between the solution properties and fiber diameter. Contiguous, bead-free, and smooth fibers were obtained when the SPG/PVA ratios were 20:80, 30:70, and 40:60. FT-IR spectra, SEM images, tensile testing, swelling ratios, and water contact angle were utilized to characterize this glutaraldehyde (Glu) vapor cross-linked nanofibers in order to analyze the morphology, functional groups, mechanical attributes, hydrophilicity, and humidity of the nanofibers for skin tissue regeneration. Furthermore, the cell culture that was studied by the use of fibroblast (L929) cells showed that these SPG-based nanofibrous scaffolds could generate the improved cell adhesion. In conclusion, it was observed that SPG/PVA nanofiber mat in a volume ratio of 20:80 after 3 day was a suitable material for improving the wound healing, as it could increase cell proliferation and migration that possessed fiber diameter. The characteristics of this nanofiber were 267 nm, contact angle of 47.75°, good swelling behavior (289%), the ultimate strength of 6.513 MPa, Young modulus of 2.665 MPa, and cell viability of 150%.

Bio-barcode technology for detection of Staphylococcus aureus protein A based on gold and iron nanoparticles.

S. aureus is one of important causes of disease, food poisoning in humans and animals. The generally methods for detection of S. aureus is time consuming. Therefore, a new method is necessary for rapid, sensitive and specific diagnosis of S. aureus. In the present study, two probes and a Bio-barcode DNA were designed for detection of S. aureus (Protein A). Firstly, magnetic nanoparticle (MNPs) and gold nanoparticle (AuNPs) were synthesized at 80 °C and 100 °C, respectively. The AuNPs and the MNPs were functionalized with probe1, Bio-barcode DNA and probe2, respectively. Target DNA was added into the nanomaterial's system containing bio-barcode DNA-AuNPs-probe1 and probe2-MNPs to formed bio-barcode DNA-AuNPs-probe1-target DNA-probe2-MNPs complex. The bio-barcode DNA-AuNPs-probe1-target DNA-probe2-MNPs complex was separated with magnetic field. Finally, the bio-barcode DNA was released from surface of complex using DTT (0.8 M) and there was isolated of nanoparticles by magnetic field and centrifuge. The fluorescence intensity of bio-barcode DNA was measured in different concentrations of S. aureus (101 to 108 CFU mL-1) by fluorescence spectrophotometry. The results showed that standard curve was linearly from 102 to 107 CFU mL-1. Limit of detection of bio-barcode assay for both PBS and real samples was 86 CFU mL-1.

CdS nanocrystals/graphene oxide-AuNPs based electrochemiluminescence immunosensor in sensitive quantification of a cancer biomarker: p53.

An ultrahigh sensitive, simple and reliable Electrochemiluminescence (ECL) immunosensor for selective quantification of p53 protein was designed according to the enhancement effects of AuNPs on ECL emission of CdS nanocrystals (CdS NCs). CdS NCs were immobilized on the glassy carbon electrode and AuNPs introduced to the process through formation of a sandwich-type immunocomplex between first anti-p53/p53/ secondary anti-p53. ECL of CdS NCs firstly evoked the SPR of AuNPs which in return amplified the CdS NCs ECL intensity. By using graphene oxide in immunosensor fabrication procedure, and attaching more AuNPs on the surface of the electrode, the ECL intensity was further increased resulting in much higher sensitivity. After applying the optimum conditions, the linear range of the developed immunosensor was found between 20 and 1000 fg/ml with a calculated limit of detection of 4 fg/ml. Moreover, the interference, reproducibility and storage stability studies of the immunosensor were investigated. Finally, immunosensor's authenticity was evaluated by detecting the p53 protein in human spikes which offers it as a potential in early detection of cancer, monitoring the cancer progress and clinical prognosis.

Molecular Landscape in Alveolar Soft Part Sarcoma: Implications for Molecular Targeted Therapy.

Alveolar soft part sarcoma (ASPS) is a highly aggressive rare soft tissue sarcoma (STS) with poor prognosis especially in the metastatic form. ASPS is resistant to standard chemotherapy. Although, early diagnosis and surgical resection of operable tumor could lead to improved patient survival but novel treatment options are needed for advanced (metastatic) ASPS. This malignancy exhibits highly angiogenic behavior which reflects hyper-activation and over expression of angiogenic factors. Understanding the molecular events in this type of sarcoma is important in finding novel molecular based targeted therapies. We aim to review molecular aspects of ASPS growth and treatment.

Intraperitoneal immunization with Urease loaded N-trimethyl Chitosan nanoparticles elicits high protection against Brucella melitensis and Brucella abortus infections.

Brucella (B) species are brucellosis causative agents, a worldwide zoonotic illness causing Malta fever in humans and abortion in domestic animals. In this work, we evaluated the vaccine potential of Trimethyl chitosan (TMC) nanoparticles formulation of Urease (TMC/Urease) against brucellosis. TMC/Urease nanoparticles and urease without any adjuvant were separately administered both orally and intraperitoneally. Intraperitoneal (i.p.) administration of urease alone as well as oral administration of both TMC/Urease nanoparticles and urease alone, elicited low titers of specific immunoglobulin G (IgG), while i.p. immunization with TMC/Urease nanoparticles induced high specific IgG production levels. As it was indicated by the cytokine assay and the antibody isotypes, i.p. immunization by urease alone, and TMC/Urease nanoparticles induced a mixed Th1-Th2 immune response, whereas oral administration of both urease alone and TMC/Urease nanoparticles induced a mixed Th1-Th17 immune response. In lymphocyte proliferation assay, spleen cells from i.p.-vaccinated mice with TMC/Urease nanoparticles showed a strong recall proliferative response. Vaccinated animals were challenged with virulent strains of B. melitensis and B. abortus. I.p. vaccination with TMC/Urease nanoparticles resulted in a high degree of protection. Altogether, our results indicated that TMC nanoparticles are a potent delivery system for i.p.-administered Brucella antigens.

Using gold nanoparticles in diagnosis and treatment of melanoma cancer.

Several studies have been devoted to clear functionalization of gold nanoparticles (AuNPs) in different fields such as cellular and molecular biology, microbiology, immunology and physiology. In line with the high diagnostic value of AuNPs, its therapeutic application has been intensively developed in tumour therapy, in recent years. One of the best clinical applications of AuNPs is its use in targeted delivery of anti-cancer drugs. Recent studies have focused on the application of AuNPs to treat melanoma - a malignant neoplasm sourced from melanocytes skin cells - with poor prognosis in advanced stages. Furthermore, early diagnosis can be successfully achieved through utilizing this technique even at early stages with localized distribution. Herein, this study details the previous researches focusing on the use of AuNPs as a novel diagnostic and therapeutic option in management of melanoma.

Ultrahigh sensitive enhanced-electrochemiluminescence detection of cancer biomarkers using silica NPs/graphene oxide: A comparative study.

The increasing progress in using nano-biomaterials for medical purposes has opened new horizons toward researchers around the globe. To investigate the presence of these nanomaterials and the impacts they might have, a comparative enhanced-electrochemiluminescence immunosensing study has been designed. The effects of utilizing graphene oxide, silica, and gold nanoparticles in cancer diagnosis were evaluated during the quantification of two major cancer biomarkers (CEA and AFP) in different approaches. In other words, first and second approaches were designed to employ nanomaterials while third and fourth approaches were developed in absence of those. Accordingly, resulted LODs experienced dramatic amplification when nano-biomaterials were included in the immunosensor modification (for AFP: 1st and 3rd approaches: 1.36fg/ml in comparison with 0.39ng/ml, and for CEA: 2nd and 4th approaches: 1.90fg/ml versus 0.46ng/ml, respectively). Correspondingly, capability of nano-biomaterials for developing highly sensitive and more efficient immunosensors was validated through selectivity, stability, reproducibility, and feasibility examinations.

Performance and Predictive Value of First Trimester Screening Markers for Down Syndrome in Iranian Pregnancies.

Objective: To investigate the performance of first trimester Down syndrome (DS) screening markers in Iranian pregnancies.Although sonographic and serum markers are currently recommended for the first trimester screening of Down syndrome, the screening performance of the markers depends on the race and ethnicity. Materials and methods: A retrospective case-control study using first trimester screening results recorded with the prenatal diagnostic multi-centers in Iran. A total of 6,384 pregnant women were examined from March 2012 to February 2017. Totally 100 Down syndrome cases and 266 matched controls were selected and the maternal characteristics, sonographic and biochemical screening data were collected. Statistical analysis was performed using logistic regression and descriptive statistics. A decision tree model was designed using the chi-squared automatic interaction detection method based on serum markers. Results: For screening of DS pregnancies, PAPP-A (cut-off 0.795 MoM) yielded the highest sensitivity (86%) and NB marker presented highest specificity (96.24%). combination of the biochemical markers PAPP-A and ß-hCG (cut-off: 1.55 MoM) showed the highest sensitivity over other combined markers. The decision-tree model based on serum markers improved (91% DR For a 5% FPR) first trimester screening performance. Conclusion: The novel decision-tree model base on serum markers revealed a better predictive value to achieve high sensitivity and specificity of first trimester Down syndrome screening in Iranian population.

Oral immunization of mice with Omp31-loaded N-trimethyl chitosan nanoparticles induces high protection against Brucella melitensis infection.

Brucellosis is a group of closely associated zoonotic bacterial illnesses caused by members of the genus Brucella. B. melitensis Omp31 is a promising candidate for a subunit vaccine against brucellosis. This study surveyed the immunogenicity of Omp31 alone and with incomplete Freund's adjuvant (Omp31-IFA) and N-trimethyl chitosan (TMC/Omp31) nanoparticles (NPs), as well as the effect of Omp31 immunization route on immunological responses and protection. After expression and purification, the recombinant Omp31 (rOmp31) was loaded onto TMC NPs by ionic gelation. The particle size, loading efficiency and in vitro release of the NPs were examined. Omp31-IFA was administered intraperitoneally, while TMC/Omp31 NPs were administered orally and intraperitoneally. According to the antibody subclasses and cytokine profile, intraperitoneal immunization by Omp31-IFA and TMC/Omp31 NPs induced T helper 1 (Th1) and Th1-Th2 immune responses, respectively. On the other hand, oral immunization with TMC/Omp31 NPs elicited a mixed Th1-Th17 immune response. Data obtained from the cell proliferation assay showed that vaccination with Omp31 stimulated a vigorous antigen-specific cell proliferative response, which could be further increased after oral immunization with TMC/Omp31 NPs. Vaccinated groups of mice when challenged with B. melitensis 16M were found to be significantly protected in the orally administered group in comparison with the intraperitoneally immunized mice. Results of this study indicated that the reason for high protection after oral vaccination can be via elicited Th17 response.

Detection of Pseudomonas aeruginosa by a triplex polymerase chain reaction assay based on lasI/R and gyrB genes.

Pseudomonas aeruginosa is a nosocomial pathogen, which, due to its inherent and acquired resistance to a wide range of antibiotics, causes high mortality rates. Therefore, rapid detection of the bacterium with high specificity and sensitivity plays a critical role in the control of the pathogenic bacterium. The aim of this study was to evaluate the accuracy and specificity of a prompt detection of the bacterium based on a triplex polymerase chain reaction that amplifies the lasI, lasR and gyrB genes. For this purpose, 30 clinical isolates of P. aeruginosa and 30 wound biopsy samples were retrieved from clinical diagnostic laboratories. After the extraction of the chromosomal DNA, the desired genes were amplified using uniplex and triplex PCR with appropriate primers. The specificity of the primers was evaluated by a comparison of the PCR results for P. aeruginosa clinical samples and non-Pseudomonas species control samples. The sensitivity of the primers was determined using a serial dilution of the genomic DNA template (100 ng to 100 fg) and by a comparison of the PCR and bacterial culture results. The results showed that the triplex PCR assay was positive for all of the samples (100%), while the PCR identifications were negative for non-Pseudomonas species. Additionally, at 10(-4) and 10(-5) diluted genomic DNA from P. aeruginosa (10 pg and 1 pg), the triplex PCR test was positive for the Las and gyrB genes in all of the samples, respectively. Based on these results, the designed primers can be used for the rapid, specific and sensitive diagnosis of P. aeruginosa in a triplex PCR assay.