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.

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.

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.

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.

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.

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.

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.

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.