The Role of Antimicrobial Peptides in Preterm Birth.

Antimicrobial peptides (AMPs) are short cationic amphipathic peptides with a wide range of antimicrobial properties and play an important role in the maintenance of immune homeostasis by modulating immune responses in the reproductive tract. As intra-amniotic infection and microbial dysbiosis emerge as common causes of preterm births (PTBs), a better understanding of the AMPs involved in the development of PTB is essential. The altered expression of AMPs has been reported in PTB-related clinical presentations, such as preterm labor, intra-amniotic infection/inflammation, premature rupture of membranes, and cervical insufficiency. Moreover, it was previously reported that dysregulation of AMPs may affect the pregnancy prognosis. This review aims to describe the expression of AMPs associated with PTBs and to provide new perspectives on the role of AMPs in PTB.

The Effects of Luminescent CdSe Quantum Dot-Functionalized Antimicrobial Peptides Nanoparticles on Antibacterial Activity and Molecular Mechanism.

BACKGROUND: With the development of bacterial resistance, the range of effective antibiotics is increasingly becoming more limited. The effective use of nanoscale antimicrobial peptides (AP) in therapeutic and diagnostic methods is a strategy for new antibiotics. METHODS: Combining both AP and cadmium selenide (CdSe) into a composite material may result in a reagent with novel properties, such as enhanced antibacterial activity, fluorescence and favorable stability in aqueous solution. RESULTS: AP-loaded CdSe NPs (AP-CdSe NPs) showed strong antibacterial activity against multidrug-resistant (MDR) Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in vitro and in vivo. Colony-forming unit (CFU) and minimum inhibitory concentration (MIC) assays showed that AP-CdSe NPs have highly effective antibacterial activity. The quantitative analysis of apoptosis by flow cytometry analysis further confirmed that MDR E. coli and S. aureus treated with AP-CdSe NPs had death rates of 98.76% and 99.13%, respectively. Also, AP-CdSe NPs was found to inhibit bacterial activity in an in vivo bacteremia model in mice infected with S. aureus. In addition, the antibacterial mechanism of AP-CdSe NPs was determined by RNA sequencing analysis. Gene ontology (GO) analysis and Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis revealed the molecular mechanism of the antibacterial effect of AP-CdSe NPs. Importantly, histopathology analysis, and hematological toxicity analysis indicated that AP-CdSe NPs had few side effects. CONCLUSION: These results demonstrate that AP loaded on CdSe NPs had a higher water solubility, bioavailability and antibacterial effect compared with raw AP. This study reports findings that are helpful for the design and development of antibacterial treatment strategies based on AP.

Antimicrobial and Amyloidogenic Activity of Peptides. Can Antimicrobial Peptides Be Used against SARS-CoV-2?

At present, much attention is paid to the use of antimicrobial peptides (AMPs) of natural and artificial origin to combat pathogens. AMPs have several points that determine their biological activity. We analyzed the structural properties of AMPs, as well as described their mechanism of action and impact on pathogenic bacteria and viruses. Recently published data on the development of new AMP drugs based on a combination of molecular design and genetic engineering approaches are presented. In this article, we have focused on information on the amyloidogenic properties of AMP. This review examines AMP development strategies from the perspective of the current high prevalence of antibiotic-resistant bacteria, and the potential prospects and challenges of using AMPs against infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Antimicrobial peptides: a promising strategy for lung cancer drug discovery?

INTRODUCTION: Antimicrobial peptides (AMPs), also called host defense peptides (HDPs), are identified in almost any form of life, which play an important role in innate immune systems. They have a broad spectrum of antifungal, antiviral, antibacterial, and anticancer activities. Lung cancer remains the leading cause of global cancer-related death. Unfortunately, lung cancer chemotherapy is accompanied by serious side effects, nonspecific toxicity, and multidrug resistance. Hence, to overcome these drawbacks, anticancer peptides (ACPs) derived from AMPs may represent a potential promising synergistic treatment strategy for lung cancer. AREAS COVERED: In this review, the authors provide the recent advancements in the use of AMPs for the treatment of lung cancer. Furthermore, the anti-lung cancer modes of action of these peptides have been fully reviewed. Importantly, various strategies for increasing the efficiency and safety of AMPs have been discussed. EXPERT OPINION: The combination of AMPs and other cancer treatment approaches such as chemotherapy, nanoparticle-based delivery systems, and photodynamic therapy can be used as a promising revolutionary strategy for the treatment of lung cancer. The most significant limitations of this strategy that need to be focused on are low efficiency and off-target events.

Hyaluronic acid and antimicrobial peptide-modified gold/silver hybrid nanocages to combat bacterial multidrug resistance.

Bacterial multidrug resistance is a major challenge for the treatment of infection. In this study, a gold-silver hybrid nanocage (Au/Ag NCs) is designed to conjugated with an antimicrobial peptide (AP) and hyaluronic acid (HA) via Au-S bond and electrostatic adsorption respectively. HA-P(Au/Ag) shows a small size (128 nm), a high efficiency of photothermal conversion, and a good stability. Under near-infrared (NIR) irradiation, HA-P(Au/Ag) effectively kills multidrug resistant bacteria-Acinetobacter baumannii (MDR-AB) by disrupting their inner and outer membrane. A pneumonia model caused by MDR-AB is established in mice. HA-P(Au/Ag) treatment reduces the number of bacterial colonies and inflammation in lung tissues and restores the structure of pulmonary alveoli. HA-P(Au/Ag)/NIR treatment increases the survival rate of pneumonia mice to 100%. Safety evaluation demonstrates that HA-P(Au/Ag) causes little cytotoxicity and hemolysis, and shows neglectable impact to the key indicators of kidney and liver function. To conclude, HA-P(Au/Ag) is a highly efficient and safe strategy that is promising to combat MDR-AB caused infection in vitro and in vivo.

Anti-bacterial activity of inorganic nanomaterials and their antimicrobial peptide conjugates against resistant and non-resistant pathogens.

This review details the antimicrobial applications of inorganic nanomaterials of mostly metallic form, and the augmentation of activity by surface conjugation of peptide ligands. The review is subdivided into three main sections, of which the first describes the antimicrobial activity of inorganic nanomaterials against gram-positive, gram-negative and multidrug-resistant bacterial strains. The second section highlights the range of antimicrobial peptides and the drug resistance strategies employed by bacterial species to counter lethality. The final part discusses the role of antimicrobial peptide-decorated inorganic nanomaterials in the fight against bacterial strains that show resistance. General strategies for the preparation of antimicrobial peptides and their conjugation to nanomaterials are discussed, emphasizing the use of elemental and metallic oxide nanomaterials. Importantly, the permeation of antimicrobial peptides through the bacterial membrane is shown to aid the delivery of nanomaterials into bacterial cells. By judicious use of targeting ligands, the nanomaterial becomes able to differentiate between bacterial and mammalian cells and, thus, reduce side effects. Moreover, peptide conjugation to the surface of a nanomaterial will alter surface chemistry in ways that lead to reduction in toxicity and improvements in biocompatibility.

New technologies in benign prostatic hyperplasia management.

PURPOSE OF REVIEW: Surgical debulking of the adenoma/transition zone has been the fundamental principle which underpins transurethral resection of the prostate - still acknowledged to be the gold-standard therapy for benign prostatic hyperplasia (BPH). However, there has been a recent resurgence in development of new BPH technologies driven by enhanced understanding of prostate pathophysiology, development of new ablative technologies, and the need for less morbid alternatives as the mean age and complexity of the treatment population continues to increase. The objective of this review is to highlight new BPH technologies and review their available clinical data with specific emphasis on unique features of the technology, procedural effectiveness and safety, and potential impact on current treatment paradigms. RECENT FINDINGS: New technologies have emerged that alter the shape of the prostate to decrease urinary obstruction and enhance delivery of a lethal thermal dose by steam injection into the transition zone of the prostate. Energy can be delivered to the prostate via a beam of high-pressure saline or focused acoustic energy to mechanically disintegrate prostate tissue. Methods of cell death are being targeted with selectivity by the arterial supply with embolization and specific to prostate cells via injectable biological therapies. SUMMARY: A number of new technologies are at various stages of development and improve on the transurethral resection of the prostate paradigm by moving closer to the ideal BPH therapy which is definitive, can be performed in minutes, in the office setting, with only local anesthesia and oral sedation.

Phase 1 and 2 studies demonstrate the safety and efficacy of intraprostatic injection of PRX302 for the targeted treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia.

BACKGROUND: PRX302 is a prostate specific antigen (PSA)-activated pore-forming protein toxin under development as a targeted approach for improving lower urinary tract symptoms (LUTS) caused by benign prostatic hyperplasia (BPH) without affecting sexual function. OBJECTIVE: To evaluate the safety and efficacy of PRX302 in men with moderate to severe BPH. DESIGN, SETTING, AND PARTICIPANTS: Eligible subjects were refractory, intolerant, or unwilling to undergo medical therapies for BPH and had International Prostate Symptom Score (IPSS) ≥12, a quality of life (QoL) score ≥3, and prostate volumes between 30 and 80 g. Fifteen patients were enrolled in phase 1 studies, and 18 patients entered phase 2 studies. INTERVENTIONS: Subjects received intraprostatic injection of PRX302 into the right and left transition zone via a transperineal approach in an office-based setting. Phase 1 subjects received increasing concentrations of PRX302 at a fixed volume; phase 2 subjects received increasing volumes per deposit at a fixed concentration. MEASUREMENTS: IPSS, QoL, prostate volume, maximum flow rate (Q(max)), International Index of Erectile Function, serum PSA levels, pharmacokinetics, and adverse events were recorded at 30, 60, 90, 180, 270, and 360 d after treatment with PRX302. RESULTS AND LIMITATIONS: Sixty percent of men in the phase 1 study and 64% of men in the phase 2 study treated with PRX302 had ≥30% improvement compared to baseline in IPSS out to day 360. Patients also experienced improvement in QoL and reduction in prostate volume out to day 360. Patients receiving ≥1 ml of PRX302 per deposit had the best response overall. PRX302 had no deleterious effect on erectile function. Adverse events were mild to moderate and transient in nature. The major study limitation was the small sample size. CONCLUSIONS: The promising safety profile and evidence of efficacy in the majority of treated subjects in these phase 1 and 2 studies supports further development of PRX302 as a minimally invasive, targeted treatment for BPH.