An In vivo study: Adjuvant activity of poly-n-vinyl-2-pyrrolidone-co-acrylic acid on immune responses against Melanoma synthetic peptide

Advances of Antimicrobial Peptide-Based Biomaterials for the Treatment of Bacterial Infections

Owing to the increase in multidrug-resistant bacterial isolates in hospitals globally and the lack of truly effective antimicrobial agents, antibiotic resistant bacterial infections have increased substantially. There is thus an urgent need to develop new antimicrobial drugs and their related formulations. In recent years, natural antimicrobial peptides (AMPs), AMP optimization, self-assembled AMPs, AMP hydrogels, and biomaterial-assisted delivery of AMPs have shown great potential in the treatment of bacterial infections. In this review, it is focused on the development prospects and shortcomings of various AMP-based biomaterials for treating animal model infections, such as abdominal, skin, and eye infections. It is hoped that this review will inspire further innovations in the design of AMP-based biomaterials for the treatment of bacterial infections and accelerate their commercialization.

In Vitro Assessment of Poly-N-Vinylpyrrolidone/Acrylic Acid Nanoparticles Biocompatibility in a Microvascular Endothelium Model

An amphiphilic copolymer of N-vinyl-2-pyrrolidone and acrylic acid—namely, p(VP-AA)-OD6000 (p(VP-AA))—was synthesized to prepare p(VP-AA) nanoparticles (NPs). Furthermore, the copolymer was linked with CFSE, and the so-prepared nanoparticles were loaded with the DiI dye to form D nanoparticles (DNPs). In this study, as demonstrated by immunofluorescence microscopy, immunofluorescence, and confocal microscopy, DNPs were readily taken up by human microvascular endothelial cells (HMEC-1) cells in a concentration-dependent manner. Upon uptake, both the CFSE dye (green stain) and the DiI dye (red stain) were localized to the cytoplasm of treated cells. Treatment with p(VP-AA) did not affect the viability of normal and challenged with LPS, HMEC-1 cells at 0.010 mg/mL and induced a dose-dependent decrease of these cells’ viability at the higher concentrations of 0.033 and 0.066 mg/mL (p ≤ 0.01; p ≤ 0.001, respectively). Furthermore, we focused on the potential immunological activation of HMEC-1 endothelial cells upon p(VP-AA) NPs treatment by assessing the expression of adhesion molecules (E-Selectin, ICAM-1, and V-CAM). NPs treatments at concentrations utilized (p = NS) did not affect individual adhesion molecules’ expression. p(VP-AA) NPs do not activate the endothelium and do not affect its viability at pharmacologically relevant concentrations.

Novel natural inhibitors targeting B-RAF(V600E) by computational study

The aim of this research was to screen the ZINC15 database to select lead compounds and drug candidates which can inhibit B-RAF (V600E). In order to identify drugs potentially inhibited B-RAF (V600E), numerous modules of Discovery Studio 4.5 were employed. Structure-based screening using LibDock was carried out followed by ADME (absorption, distribution, metabolism, excretion) and toxicity prediction. CDOCKER was performed to demonstrate the binding affinity and mechanism between ligands and B-RAF(V600E). To evaluate whether ligand-receptor complexes were stable, molecular dynamics were employed. Two novel natural compounds (ZINC000100168592 and ZINC000049784088) from ZINC15 database were found binding to B-RAF(V600E) with more favorable interaction energy in comparison with the reference drug Vemurafenib. Also, they were predicted with less ames mutagenicity, rodent carcinogenicity, non-developmental toxic potential and tolerance to cytochrome P450 2D6 (CYP2D6). The molecular dynamics simulation analysis indicated that the compound-B-RAF(V600E) complexes had more favorable potential energy compared with Vemurafenib and they can exist in natural environments stably. The result of this study shows that ZINC000100168592 and ZINC000049784088 are ideal leading potential compounds to inhibit B-RAF(V600E). The findings of this study and these selected drug candidates greatly contributed to the medication design and improvement of B-RAF(V600E) and other proteins.

Microgels and hydrogels as delivery systems for antimicrobial peptides

Due to rapid development of bacterial resistance against antibiotics, an emerging health crisis is underway, where 'simple' infections may no longer be treatable. Antimicrobial peptides (AMPs) constitute a class of substances attracting interest in this context. So far, research on AMPs has primarily focused on the identification of potent and selective peptides, as well as on the action mode of such peptides. More recently, there has been an increasing awareness that the delivery of AMPs is challenging due to their size, net positive charge, amphiphilicity, and proteolytic susceptibility. Hence, successful development of AMP therapeutics will likely require also careful design of efficient AMP delivery systems. In the present brief review, we discuss microgels, as well as related polyelectrolyte complexes and macroscopic hydrogels, as delivery systems for AMPs. In doing so, key factors for peptide loading and release are outlined and exemplified, together with consequences of this for functional performance relating to antimicrobial effects and cell toxicity.

Complexation between antimicrobial peptides and polyelectrolytes

As a result of increasing bacterial resistance against antibiotics, we are facing an emerging health crisis, in which 'simple' infections may no longer be treatable. One class of molecules attracting interest in this context is antimicrobial peptides (AMPs), and considerable research efforts have been directed to identifying selective and potent AMPs. In addition, since in vivo delivery of AMPs is challenging, there is an emerging awareness that successful development of AMP therapeutics can be facilitated by careful design of AMPs delivery systems. In the present overview, we discuss polyelectrolyte complexation as a strategy to deliver AMPs. In doing so, key factors for AMP-polyelectrolyte complexation are illustrated for AMP-polyelectrolyte nanoparticle formation, as well as for AMP incorporation in polyelectrolyte microgels and multilayer structures, and consequences of these for functional performance exemplified.