Strategies to Overcome Antimicrobial Resistance in Nosocomial Infections, A Review and Update.

Nosocomial infections, also known as healthcare-associated infections, are a signif-icant global concern due to their strong association with high mortality and morbidity in both developed and developing countries. These infections are caused by a variety of pathogens, particularly the ESKAPE group of bacteria, which includes the six pathogens Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudo-monas aeruginosa, and Enterobacter spp. These bacteria have demonstrated noteworthy re-sistance to different antibiotics. Antimicrobial resistance mechanisms can manifest in various forms, including restricting drug uptake, modifying drug targets, inactivating drugs, active drug efflux, and biofilm formation. Accordingly, various strategies have been developed to combat antibiotic-resistant bacteria. These strategies encompass the development of new antibiotics, the utilization of bacterio-phages that specifically target these bacteria, antimicrobial combination therapy and the use of peptides or enzymes that target the genomes or essential proteins of resistant bacteria. Among promising approaches to overcome antibiotic resistance, the CRISPR/Cas system stands out and offers many advantages. This system enables precise and efficient editing of genetic material at specific locations in the genome. Functioning as a bacterial "adaptive im-mune system," the CRISPR/Cas system recognizes, degrades, and remembers foreign DNA sequences through the use of spacer DNA segments that are transcribed into CRISPR RNAs (crRNA). This paper has focused on nosocomial infections, specifically the pathogens involved in hospi-tal infections, the mechanisms underlying bacterial resistance, and the strategies currently em-ployed to address this issue. Special emphasis has been placed on the application of CRISPR/Cas technology for overcoming antimicrobial resistance.

VEGFR2 Mimicking Peptide Inhibits the Proliferation of Human Umbilical Vein Endothelial Cells (Huvecs) by Blocking VEGF.

INTRODUCTION: A variety of key human physiological processes rely on angiogenesis, ranging from reproduction and fetal growth to wound healing and tissue repair. Furthermore, this process significantly contributes to tumor progression, invasion, and metastasis. As the strongest inducer of angiogenesis, Vascular Endothelial Growth Factor (VEGF) and its receptor (VEGFR) are targets of therapeutic research for blocking pathological angiogenesis. OBJECTIVE: Preventing the interaction between VEGF and VEGFR2 by a peptide is a promising strategy for developing antiangiogenic drug candidates. This study was aimed at designing and evaluating VEGF-targeting peptides using in silico and in vitro techniques. METHODS: The VEGF binding site of VEGFR2 was considered a basis for peptide design. The interaction of VEGF and all three peptides derived from VEGFR2 were analyzed using ClusPro tools. In a complex with VEGF, the peptide with a higher docking score was evaluated to confirm its stability using molecular dynamics (MD) simulation. The gene coding for the selected peptide was cloned and expressed in E. coli BL21. The bacterial cells were cultured on a large scale, and the expressed recombinant peptide was purified using Ni-NTA chromatography. Refolding of the denatured peptide was carried out by the stepwise removal of the denaturant. The reactivity of peptides was confirmed using western blotting and enzyme-linked immunosorbent assay (ELISA) assays. Finally, the inhibition potency of the peptide on human umbilical vein endothelial cells was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl- 2H-tetrazolium bromide (MTT) assay. RESULTS: Among three peptides, the peptide with the best docking pose and the highest affinity for VEGF was selected for further studies. Then the stability of the peptide was confirmed over the 100 ns MD simulation. After in silico analyses, the selected peptide was presented for in vitro analysis. Expression of the selected peptide in E. coli BL21 resulted in a pure peptide with a yield of approximately 200 µg/ml. Analysis by ELISA revealed the high reactivity of the peptide with VEGF. Western blot analysis confirmed the specific reactivity of selected peptides with VEGF. The MTT assay revealed the growth inhibitory effect of the peptide on human umbilical vein endothelial cells with an IC50 value of 247.8 µM. CONCLUSION: In summary, the selected peptide demonstrated a promising inhibitory effect on human umbilical vein endothelial cells that could be a valuable anti-angiogenic candidate for further assessment. Additionally, these in silico and in vitro data provide new insights into peptide design and engineering.

In silico Validation of Pseudomonas aeruginosa Exotoxin A Domain I Interaction with the Novel Human scFv Antibody.

BACKGROUND: Pseudomonas (P.) aeruginosa is one of the leading causes of nosocomial infections. The pathogenicity of P. aeruginosa is related to its inherent antimicrobial resistance and the diverse virulence factors of this bacterium. Owing to the specific role of exotoxin A in P. aeruginosa pathogenesis, it is known as a promising therapeutic candidate to develop antibodies as an alternative to antibiotics. OBJECTIVE: The present study aimed to validate the interaction between a single-chain fragment variable (scFv) antibody identified from an scFv phage library against domain I exotoxin A by bioinformatic tools. METHODS: For this, several bioinformatics tools, including Ligplot, Swiss PDB viewer (SPDBV), PyMOL, I-TASSER, Gromacs, and ClusPro servers were used to evaluate the interaction of scFv antibody with P. aeruginosa exotoxin A. The I-TASSER server was utilized to predict the function and structure of proteins. The interaction of two proteins was analyzed using ClusPro tools. The best docking results were further analyzed with Ligplot, Swiss PDB viewer, and PyMOL. Consequently, molecular dynamics simulation was utilized to predict the stability of the secondary structure of the antibody and the binding energy of the scFv antibody to the domain I of exotoxin A. RESULTS: As a result, we demonstrated that data from computational biology could provide proteinprotein interaction information between scFv antibody/domain I exotoxin A and offers new insights into antibody development and therapeutic expansion. CONCLUSION: In summary, a recombinant human scFv capable of neutralizing P. aeruginosa exotoxin A is recommended as a promising treatment for infections caused by P. aeruginosa.

The Role of Interferons in Long Covid Infection.

Although the new generation of vaccines and anti-COVID-19 treatment regimens facilitated the management of acute COVID-19 infections, concerns about post-COVID-19 syndrome or Long Covid are rising. This issue can increase the incidence and morbidity of diseases such as diabetes, and cardiovascular, and lung infections, especially among patients suffering from neurodegenerative disease, cardiac arrhythmias, and ischemia. There are numerous risk factors that cause COVID-19 patients to experience post-COVID-19 syndrome. Three potential causes attributed to this disorder include immune dysregulation, viral persistence, and autoimmunity. Interferons (IFNs) are crucial in all aspects of post-COVID-19 syndrome etiology. In this review, we discuss the critical and double-edged role of IFNs in post-COVID-19 syndrome and how innovative biomedical approaches that target IFNs can reduce the occurrence of Long Covid infection.

Recent advances for cancer detection and treatment by microfluidic technology, review and update.

Numerous cancer-associated deaths are owing to a lack of effective diagnostic and therapeutic approaches. Microfluidic systems for analyzing a low volume of samples offer a precise, quick, and user-friendly technique for cancer diagnosis and treatment. Microfluidic devices can detect many cancer-diagnostic factors from biological fluids and also generate appropriate nanoparticles for drug delivery. Thus, microfluidics may be valuable in the cancer field due to its high sensitivity, high throughput, and low cost. In the present article, we aim to review recent achievements in the application of microfluidic systems for the diagnosis and treatment of various cancers. Although microfluidic platforms are not yet used in the clinic, they are expected to become the main technology for cancer diagnosis and treatment. Microfluidic systems are proving to be more sensitive and accurate for the detection of cancer biomarkers and therapeutic strategies than common assays. Microfluidic lab-on-a-chip platforms have shown remarkable potential in the designing of novel procedures for cancer detection, therapy, and disease follow-up as well as the development of new drug delivery systems for cancer treatment.

Engineering of Ocriplasmin Variants by Bioinformatics Methods for the Reduction of Proteolytic and Autolytic Activities.

Background: Ocriplasmin has been developed for the induction of posterior vitreous detachment in patients with vitreomacular adhesion. At physiological pH, ocriplasmin is susceptible to autolytic and proteolytic degradation, limiting its activity duration. These undesirable properties of ocriplasmin can be reduced by site-directed mutagenesis, so that its enzymatic activities can be augmented. This study aimed to design ocriplasmin variants with improved biological/physicochemical characteristics via bioinformatics tools. Methods: This study was performed in Tabriz University of Medical Sciences, Tabriz, Iran, 2019. Through site-directed mutagenesis, three ocriplasmin variants were designed. Structural analysis was performed on the wild-type variant and the mutant variants using the Protein Interactions Calculator (PIC) server. The interactions between the S-2403 substrate and the ocriplasmin variants were studied by molecular docking simulations, and binding capability was evaluated by the calculation of free binding energy. The conformational features of protein-substrate complex systems for all the variants were evaluated using molecular dynamic simulations at 100 nanoseconds. Results: The structural analysis of ocriplasmin revealed that the substitution of threonine for alanine 59 significantly reduced proteolytic activity, while the substitution of glutamic acid for lysine 156 influenced autolytic function. The molecular docking simulation results indicated the appropriate binding of the substrate to the ocriplasmin variants with high-to-low affinities. The binding affinity of the wild-type variant for the substrate was higher than that between the mutant variants and the substrate. Simulation analyses, consisting of the root-mean-square deviation, the root-mean-square fluctuation, and the center-of-mass average distance showed a higher affinity of the substrate for the wild type than for the mutant variants. Conclusion: The mutational analysis of ocriplasmin revealed that A59T and K156E mutagenesis could be used for the development of a new variant with higher therapeutic efficacy.

Rational Design of Anti-Angiogenic Peptides to Inhibit VEGF/VEGFR2 Interactions for Cancer Therapeutics.

BACKGROUND: Angiogenesis is a critical physiological process that plays a key role in tumor progression, metastatic dissemination, and invasion. In the last two decades, the vascular endothelial growth factor (VEGF) signaling pathway has been the area of extensive researches. VEGF executes its special effects by binding to vascular endothelial growth factor receptors (VEGFRs), particularly VEGFR-2. OBJECTIVE: The inhibition of VEGF/VEGFR2 interaction is known as an effective cancer therapy strategy. The current study pointed to design and model an anti-VEGF peptide based on VEGFR2 binding regions. METHOD: The large-scale peptide mutation screening was used to achieve a potent peptide with high binding affinity to VEGF for possible application in inhibition of VEGF/VEGFR2 interaction. The AntiCP and Peptide Ranker servers were used to generate the possible peptides library with anticancer activities and prediction of peptides bioactivity. Then, the interaction of VEGF and all library peptides were analyzed using Hex 8.0.0 and ClusPro tools. A number of six peptides with favorable docking scores were achieved. All of the best docking scores of peptides in complexes with VEGF were evaluated to confirm their stability, using molecular dynamics simulation (MD) with the help of the GROMACS software package. RESULTS: As a result, two antiangiogenic peptides with 13 residues of PepA (NGIDFNRDFFLGL) and PepC (NGIDFNRDKFLFL) were achieved and introduced to inhibit VEGF/VEGFR2 interactions. CONCLUSIONS: In summary, this study provided new insights into peptide-based therapeutics development for targeting VEGF signaling pathway in tumor cells. PepA and PepC are recommended as potentially promising anticancer agents for further experimental evaluations.

New Developments in Anti-Angiogenic Therapy of Cancer, Review and Update.

BACKGROUND: Angiogenesis is one of the critical physiological processes, by which the new blood vessels are generated from the pre-existing vessels in the early stage of vasculogenesis. While normal angiogenesis is critical for development and tissue growth, pathologic angiogenesis is important for the growth and spread of cancers by supplying nutrients and oxygen as well as providing a conduit for distant metastasis. In the last two decades, angiogenesis has been the area of extensive researches, indicating antiangiogenic target therapy as an effective strategy for cancer therapy. At present, this field has become a major avenue for research and development of novel therapeutics. OBJECTIVE: This review is dedicated to an updated review of the most prominent antiangiogenic agents, emphasizing the novel advancements and their applications, in particular, in the fields of antibodies, peptides, vaccines, endogenous inhibitors, Nanoparticles (NPs), antiangiogenic oligonucleotides and small molecules. Also, the potential role of 3D microfluidic models as an affordable and time-saving tool for angiogenesis investigations are discussed. METHODS: Firstly, we collected and summarized new developments that have occurred in all review and research articles in databases. Then, we used important keywords related to antiangiogenic target therapy and their applications for retrieval of most relevant data. RESULTS: This review is based on recent research and review articles and intended to cover all newly discovered agents inhibiting tumor angiogenesis and in particular, VEGF. CONCLUSION: New research studies have shown that anti-angiogenesis agents especially, in the form of combination therapy are effective in various cancers treatment.

Anti-cancer Immunotoxins, Challenges, and Approaches.

The development of recombinant immunotoxins (RITs) as a novel therapeutic strategy has made a revolution in the treatment of cancer. RITs result from the fusion of antibodies to toxin proteins for targeting and eliminating cancerous cells by inhibiting protein synthesis. Despite indisputable outcomes of RITs regarding inhibition of multiple cancer types, high immunogenicity has been known as the main obstacle in the clinical use of RITs. Various strategies have been proposed to overcome these limitations, including immunosuppressive therapy, humanization of the antibody fragment moiety, generation of immunotoxins originated from endogenous human cytotoxic enzymes, and modification of the toxin moiety to escape the immune system. This paper is devoted to review recent advances in the design of immunotoxins with lower immunogenicity.

Development and characterization of a novel conductive polyaniline-g-polystyrene/Fe3O4 nanocomposite for the treatment of cancer.

The goal of this study is to synthesize, characterize and investigate some physicochemical properties of conductive polyaniline-g-polystyrene/Fe3O4 (Fe3O4/PSt-g-PANi) nanocomposites. For this purpose, initially, Fe3O4 nanoparticles were synthesized by a co-precipitation method. Then, the desired nanocomposite was synthesized in two steps. First, the atom transfer radical polymerization (ATRP) of styrene was performed using an ATRP initiator attached to the surface of Fe3O4 nanoparticles, followed by functionalization of the Fe3O4-PSt with amine groups (-NH2). Second, surface oxidative graft copolymerization of aniline was accomplished using the -NH2 moieties on the Fe3O4/PSt-NH2 as the anchoring sites. The prepared materials were characterized by various instruments, including TEM, SEM, TGA, EDX, FT-IR, XRD and conductivity measurements. The results indicated that the synthesized conductive polymer/Fe3O4 nanocomposites had higher electrical conductivity and thermal resistance than those of the corresponding homopolymers.

The role of microRNAs and nanoparticles in ovarian cancer: a review.

MicroRNAs (miRNAs) have had a revolutionary impact on cancer research over the recent years. They emerge as important players in tumourigenesis, leading to a paradigm shift in oncology. Ovarian cancer is the leading cause of death among gynaecologic malignancies. Therefore, there is a strong need for prognostic and predictive markers for early diagnosis which helps optimize and personalize treatment. Asymptomatically, ovarian cancer is often diagnosed at advanced and incurable stages. Efficient targeting and sustained release of miRNAs/anti-miRNAs using nanoparticles conjugated with antibodies and/or peptides could reduce the required therapeutic dosage while minimizing systemic and cellular toxicity. Given miRNAs importance in clinical oncology, here we focus on the development of miRNA nanoformulations to achieve enhanced cellular uptake, bioavailability and accumulation at the tumour site. Although many obstacles need to be overcome, miRNA therapy could be a powerful tool for ovarian cancer prevention and treatment. In this review, we discuss about the emerging roles of miRNAs in various aspects of ovarian cancer.

ABT-737, Synergistically Enhances Daunorubicin-Mediated Apoptosis in Acute Myeloid Leukemia Cell Lines.

PURPOSE: Intensive chemotherapy with daunorubicin (DNR) is associated with serious side effects in acute myeloid leukemia (AML) patients. In this study the effect of small-molecule BH3-mimetic, ABT-737, on the sensitivity of HL60 and U937 AML cell lines was investigated. METHODS: The cytotoxic effects of DNR and ABT-737, alone or in combination were assessed using MTT assay and combination index analysis. The effects of treatments on the cell proliferation was determined by trypan blue assay. ELISA cell death assay was used for measurement of apoptosis. RESULTS: IC50 values of DNR and ABT-737 were 2.52 and 0.59 µM for HL-60 cells line and 1.31 and 0.80 µM for U937 cell line at 24 h, respectively. Surprisingly, combination treatment significantly lowered the IC50 values in a synergic manner in both cell lines. Moreover, treatment with a mixture of two agents had more growth inhibition effect relative to the monotherapy. RESULTS of apoptosis assay showed that the cytotoxic effects are related to the enhancement of apoptosis. CONCLUSION: Our study suggests that ABT-737 synergistically enhances the cytotoxic effect of DNR in AML cell lines and therefore may be useful to overcome chemoresistance of leukemia patients.

Inhibitory effects of ß-cyclodextrin-helenalin complexes on H-TERT gene expression in the T47D breast cancer cell line - results of real time quantitative PCR.

BACKGROUND: Nowadays, the encapsulation of cytotoxic chemotherapeutic agents is attracting interest as a method for drug delivery. We hypothesized that the efficiency of helenalin might be maximized by encapsulation in ß-cyclodextrin nanoparticles. Helenalin, with a hydrophobic structure obtained from flowers of Arnica chamissonis and Arnica Montana, has anti-cancer and anti-inflammatory activity but low water solubility and bioavailability. ß-Cyclodextrin (ß-CD) is a cyclic oligosaccharide comprising seven D-glucopyranoside units, linked through 1,4-glycosidic bonds. MATERIALS AND METHODS: To test our hypothesis, we prepared ß-cyclodextrin- helenalin complexes to determine their inhibitory effects on telomerase gene expression by real-time polymerase chain reaction (q-PCR) and cytotoxic effects by colorimetric cell viability (MTT) assay. RESULTS: MTT assay showed that not only ß-cyclodextrin has no cytotoxic effect on its own but also it demonstrated that ß-cyclodextrin- helenalin complexes inhibited the growth of the T47D breast cancer cell line in a time and dose-dependent manner. Our q-PCR results showed that the expression of telomerase gene was effectively reduced as the concentration of ß-cyclodextrin-helenalin complexes increased. CONCLUSIONS: ß-Cyclodextrin-helenalin complexes exerted cytotoxic effects on T47D cells through down-regulation of telomerase expression and by enhancing Helenalin uptake by cells. Therefore, ß-cyclodextrin could be superior carrier for this kind of hydrophobic agent.