Antimicrobial peptide-conjugated graphene coatings for prevention and treatment of bacterial infections.

Graphene, a two-dimensional hexagonal lattice of carbon atoms, displays remarkable physicochemical properties. In contrast to classical chemical exfoliation, chemical vapour deposition (CVD) technology has enabled the production of graphene that is both continuous and transparent. CVD graphene coatings on biomedical devices, such as contact lenses (CLs), offer several advantages, such as shielding from electromagnetic wave interference and dehydration protection.

Boronic acid derivatives inhibit Candida albicans growth by compromising energy metabolism.

Introduction: Fungal infections represent a global health concern with significant implications for human well-being. Among them, refractory and sight-threatening fungal keratitis (FK) poses a serious threat to ocular health. This underscores an urgent need for developing novel antifungal agents to meet clinical demands.

Discrete Brush Polymers Enhance F MRI Performance through Architectural Precision.

The development of metal-free magnetic resonance imaging (MRI) agents demands precise control over molecular architecture to achieve optimal performance. Current fluorine-based contrast agents rely on maximizing fluorine content (>20 wt %) for sensitivity, requiring extensive solubilizing groups that lead to signal-diminishing aggregation. Here we show that discrete brush polymers ( = 1.

Propranolol Ameliorates the Antifungal Activity of Azoles in Invasive Candidiasis.

The effectiveness of current antifungal therapies is hampered by the emergence of drug resistance strains, highlighting an urgent need for new alternatives such as adjuvant antifungal treatments. This study aims to examine the synergism between propranolol and antifungal drugs, based on the premise that propranolol is known to inhibit fungal hyphae. In vitro studies demonstrate that propranolol potentiates the antifungal activity of azoles and that the effect is more pronounced for propranolol-itraconazole combination.

Recent advances in copper and copper-derived materials for antimicrobial resistance and infection control.

Antibacterial properties of copper have been known for ages. With the rise of antimicrobial resistance (AMR), hospital-acquired infections, and the current SARS-CoV-2 pandemic, copper and copper-derived materials are being widely researched for healthcare ranging from therapeutics to advanced wound dressing to medical devices. We cover current research that highlights the potential uses of metallic and ionic copper, copper alloys, copper nanostructures, and copper composites as antibacterial, antifungal, and antiviral agents, including those against the SARS-CoV-2 virus.

Hybrid derivative of cathelicidin and human beta defensin-2 against Gram-positive bacteria: A novel approach for the treatment of bacterial keratitis.

Bacterial keratitis (BK) is a major cause of corneal blindness globally. This study aimed to develop a novel class of antimicrobial therapy, based on human-derived hybrid host defense peptides (HyHDPs), for treating BK. HyHDPs were rationally designed through combination of functional amino acids in parent HDPs, including LL-37 and human beta-defensin (HBD)-1 to -3.

Ocular Delivery of Predatory Bacteria with Cryomicroneedles Against Eye Infection.

The development of potent antibiotic alternatives with rapid bactericidal properties is of great importance in addressing the current antibiotic crisis. One representative example is the topical delivery of predatory bacteria to treat ocular bacterial infections. However, there is a lack of suitable methods for the delivery of predatory bacteria into ocular tissue.

Core-Shell Structured Antimicrobial Nanofiber Dressings Containing Herbal Extract and Antibiotics Combination for the Prevention of Biofilms and Promotion of Cutaneous Wound Healing.

Burn wounds are susceptible to microbial invasion from both resident and exogenous bacteria, which becomes a critical public health issue and causes substantial economic burden. There is a perceived demand to produce new antimicrobial wound dressings that hinder bacterial colonization while accelerating the healing process and hence would provide an improved standard of care for patients. Since ancient times, herbal extracts from medicinally important plants have extensively been used for treating burn injuries.

Mussel-Inspired Durable Antimicrobial Contact Lenses: The Role of Covalent and Noncovalent Attachment of Antimicrobials.

Contact lens is a major risk factor for microbial keratitis among contact lens wearers. Chemical strategies that can prevent microbial adhesion and biofilm formation are required to improve a wearer's hygiene and safety. Taking advantage of the material-independent properties of a polydopamine (pDA) coating, we investigated the role of covalent/noncovalent interactions of the antimicrobials and pDA in conferring long-term antimicrobial activities.

Nucleic acid peptide nanogels for the treatment of bacterial keratitis.

Cage-shaped nucleic acid nanocarriers are promising molecular scaffolds for the organization of polypeptides. However, there is an unmet need for facile loading strategies that truly emulate nature's host-guest systems to drive encapsulation of antimicrobial peptides (AMPs) without loss of biological activity. Herein, we develop DNA nanogels with rapid in situ loading of L12 peptide during the thermal annealing process.

Wound healing properties of magnesium mineralized antimicrobial nanofibre dressings containing chondroitin sulphate - a comparison between blend and core-shell nanofibres.

The development of antimicrobial nanofibre dressings that can protect the injured tissues from commensal pathogens while promoting tissue regeneration finds enormous potential in plastic and reconstructive surgery practices. To achieve this goal, we investigated the effect of chondroitin sulphate on the morphology, mechanical properties, wettability and biocompatibility of polydopamine crosslinked electrospun gelatin nanofibres containing mineralized magnesium. To extend the durability of dressings, we prepared composite dressings containing polycaprolactone (PCL) and gelatin as blend or core-shell nanofibres.

Rational Substitution of ε-Lysine for α-Lysine Enhances the Cell and Membrane Selectivity of Pore-Forming Melittin.

Here, we present a rational approach that enhances the membrane selectivity of a prolific pore-forming peptide, melittin, based on experimental observations that the cationic polymer, ε-polylysine, disrupts bacterial membranes with greater affinity over mammalian cells when compared to poly-l-lysine and poly-d-lysine. We systematically replaced three α-lysine residues in melittin with ε-lysine residues and identified key residues that are important for cytotoxicity. We then assessed the antimicrobial properties of the modified peptides which carry two or three ε-lysyl residues.

Multifunctional Antimicrobial Nanofiber Dressings Containing ε-Polylysine for the Eradication of Bacterial Bioburden and Promotion of Wound Healing in Critically Colonized Wounds.

Bacterial colonization of acute and chronic wounds is often associated with delayed wound healing and prolonged hospitalization. The rise of multi-drug resistant bacteria and the poor biocompatibility of topical antimicrobials warrant safe and effective antimicrobials. Antimicrobial agents that target microbial membranes without interfering with the mammalian cell proliferation and migration hold great promise in the treatment of traumatic wounds.

Protective Action of Linear Polyethylenimine against Colonization and Exaggerated Inflammation and .

Increased evolution of multidrug resistant pathogens necessitates the development of multifunctional antimicrobials. There is a perceived need for developing new antimicrobials that can interfere with acute inflammation after bacterial infections. Here, we investigated the therapeutic potential of linear polyethylenimine (LPEI) and .

Design and Syntheses of Highly Potent Teixobactin Analogues against Staphylococcus aureus, Methicillin-Resistant Staphylococcus aureus (MRSA), and Vancomycin-Resistant Enterococci (VRE) in Vitro and in Vivo.

The cyclic depsipeptide, teixobactin, kills a number of Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), and Mycobacterium tuberculosis without detectable resistance. To date, teixobactin is the only molecule in its class that has shown in vivo antibacterial efficacy. In this work, we designed and synthesized 10 new in vivo ready teixobactin analogues.

Antimicrobial Activity and Cell Selectivity of Synthetic and Biosynthetic Cationic Polymers.

The mammalian and microbial cell selectivity of synthetic and biosynthetic cationic polymers has been investigated. Among the polymers with peptide backbones, polymers containing amino side chains display greater antimicrobial activity than those with guanidine side chains, whereas ethylenimines display superior activity over allylamines. The biosynthetic polymer ε-polylysine (εPL) is noncytotoxic to primary human dermal fibroblasts at concentrations of up to 2,000 μg/ml, suggesting that the presence of an isopeptide backbone has greater cell selectivity than the presence of α-peptide backbones.

Bio-inspired crosslinking and matrix-drug interactions for advanced wound dressings with long-term antimicrobial activity.

There is a growing demand for durable advanced wound dressings for the management of persistent infections after deep burn injuries. Herein, we demonstrated the preparation of durable antimicrobial nanofiber mats, by taking advantage of strong interfacial interactions between polyhydroxy antibiotics (with varying number of OH groups) and gelatin and their in-situ crosslinking with polydopamine (pDA) using ammonium carbonate diffusion method. Polydopamine crosslinking did not interfere with the antimicrobial efficacy of the loaded antibiotics.

Latent Oxidative Polymerization of Catecholamines as Potential Cross-linkers for Biocompatible and Multifunctional Biopolymer Scaffolds.

Electrospinning of naturally occurring biopolymers for biological applications requires postspinning cross-linking for endurance in protease-rich microenvironments and prevention of rapid dissolution. The most commonly used cross-linkers often generate cytotoxic byproducts, which necessitate high concentrations or time-consuming procedures. Herein, we report the addition of "safe" catecholamine cross-linkers to collagen or gelatin dope solutions followed by electrospinning yielded junction-containing nanofibrous mats.

Insight into membrane selectivity of linear and branched polyethylenimines and their potential as biocides for advanced wound dressings.

Unlabelled: We report here structure-property relationship between linear and branched polyethylene imines by examining their antimicrobial activities against wide range of pathogens. Both the polymers target the cytoplasmic membrane of bacteria and yeasts, eliciting rapid microbicidal properties. Using multiscale molecular dynamic simulations, we showed that, in both fully or partially protonated forms LPEI discriminates between mammalian and bacterial model membranes whereas BPEI lacks selectivity for both the model membranes.

Multifunctional Polyphenols- and Catecholamines-Based Self-Defensive Films for Health Care Applications.

In an era of relentless evolution of antimicrobial resistance, there is an increasing demand for the development of efficient antimicrobial coatings or surfaces for food, biomedical, and industrial applications. This study reports the laccase-catalyzed room-temperature synthesis of mechanically robust, thermally stable, broad spectrum antimicrobial films employing interfacial interactions between poly(vinyl alcohol), PVA, and 14 naturally occurring catecholamines and polyphenols. The oxidative products of catecholamines and polyphenols reinforce the PVA films and also alter their surface and bulk properties.