The Study of Antistaphylococcal Potential of Omiganan and Retro-Omiganan Under Flow Conditions.

Staphylococcus aureus is considered one of the leading pathogens responsible for infections in humans and animals. The heterogeneous nature of diseases caused by these bacteria is due to the occurrence of multiple strains, differentiated by several mechanisms of antibiotic resistance and virulence factors. One of these is the ability to form biofilm.

Synthesis and Characterization of Antibacterial Chitosan Films with Ciprofloxacin in Acidic Conditions.

This work presents the results of research on obtaining chitosan (CS) films containing on their surface ciprofloxacin (CIP). A unique structure was obtained that not only gives new properties to the films, but also changes the way of coverage and structure of the surface. The spectroscopic test showed that in the process of application of CIP on the surface of CS film, CIP was converted from its crystalline form to an amorphic one, hence improving its bioavailability.

Quaternary Ammonium Salts of Cationic Lipopeptides with Lysine Residues - Synthesis, Antimicrobial, Hemolytic and Cytotoxic Activities.

Ultrashort cationic lipopeptides (USCLs) and quaternary ammonium salts constitute two groups of cationic surfactants with high antimicrobial activity. This study aimed to investigate the influence of quaternization of the amino group of the lysine side chain in USCLs on their antimicrobial, hemolytic and cytotoxic activities. To do this, two series of lipopeptides were synthesized, USLCs and their quaternized analogues containing trimethylated lysine residues - qUSCLs (quaternized ultrashort cationic lipopeptides).

Evaluation of Linkers' Influence on Peptide-Based Piezoelectric Biosensors' Sensitivity to Aldehydes in the Gas Phase.

Recent findings qualified aldehydes as potential biomarkers for disease diagnosis. One of the possibilities is to use electrochemical biosensors in point-of-care (PoC), but these need further development to overcome some limitations. Currently, the primary goal is to enhance their metrological parameters in terms of sensitivity and selectivity.

Influence of Lipidation Pattern of the KR12 Fragment of Peptide LL-37 on Its Antibacterial and Hemolytic Activities.

Contemporary medicine has been confronted by multidrug resistance. Therefore, new antibiotics are sought to alleviate the problem. In this study, we estimated the effect of the positioning and extent of lipidation (mainly octanoic acid residue) in the KR12-NH molecule on antibacterial and hemolytic activities.

Discovering highly potent antimicrobial peptides with deep generative model HydrAMP.

Antimicrobial peptides emerge as compounds that can alleviate the global health hazard of antimicrobial resistance, prompting a need for novel computational approaches to peptide generation. Here, we propose HydrAMP, a conditional variational autoencoder that learns lower-dimensional, continuous representation of peptides and captures their antimicrobial properties. The model disentangles the learnt representation of a peptide from its antimicrobial conditions and leverages parameter-controlled creativity.

Interaction of Positively Charged Oligopeptides with Blood Plasma Proteins.

In this project, we combine two areas of research, experimental characterization and molecular docking studies of the interaction of positively charged oligopeptides with crucial blood plasma proteins. The investigated peptides are rich in NH groups of amino acid side chains from Dap, Orn, Lys, and Arg residues, which are relevant in protein interaction. The peptides are 9- and 11-mer with the following sequences: (Lys-Dab-Dab-Gly-Orn-Pro-His-Lys-Arg-Lys-Dbt), (Lys-Dab-Ala-Gly-Orn-Pro-His-Lys-Arg), and (Lys-Dab-Dab-Gly-Orn-Pro-Phe(2-F)-Lys-Arg).

Glycosylated Lipopeptides-Synthesis and Evaluation of Antimicrobial Activity and Cytotoxicity.

Ultrashort cationic lipopeptides (USCLs) are promising antimicrobial agents that may be used to combat pathogens such as bacteria and fungi. USCLs consist of a few basic amino acid residues and at least one lipid moiety, usually a fatty acid chain. Generally, USCLs are potent antimicrobials but their major shortcoming is a relatively high cytotoxicity and hemolytic activity.

Activity of Novel Ultrashort Cyclic Lipopeptides against Biofilm of Isolated from VVC in the Ex Vivo Animal Vaginal Model and BioFlux Biofilm Model-A Pilot Study.

In recent years, clinicians and doctors have become increasingly interested in fungal infections, including those affecting the mucous membranes. Vulvovaginal candidiasis (VVC) is no exception. The etiology of this infection remains unexplained to this day, as well as the role and significance of asymptomatic vaginal colonization.

Understanding the Role of Self-Assembly and Interaction with Biological Membranes of Short Cationic Lipopeptides in the Effective Design of New Antibiotics.

This study investigates short cationic antimicrobial lipopeptides composed of 2-4 amino acid residues and C-C fatty acids attached to the N-terminal part of the peptides. The findings were discussed in the context of the relationship among biological activity, self-assembly, stability, and membrane interactions. All the lipopeptides showed the ability to self-assemble in PBS solution.

In Vitro Activity of Novel Lipopeptides against Triazole-Resistant .

Aspergillosis, which is mainly sustained by , includes a broad spectrum of diseases. They are usually severe in patients with co-morbidities. The first-line therapy includes triazoles, for which an increasing incidence of drug resistance has been lately described.

The Effect of Conjugation with Octaarginine, a Cell-Penetrating Peptide on Antifungal Activity of Imidazoacridinone Derivative.

Acridine cell-penetrating peptide conjugates are an extremely important family of compounds in antitumor chemotherapy. These conjugates are not so widely analysed in antimicrobial therapy, although bioactive peptides could be used as nanocarriers to smuggle antimicrobial compounds. An octaarginine conjugate of an imidazoacridinone derivative (Compound ) synthetized by us exhibited high antifungal activity against reference and fluconazole-resistant clinical strains (MICs ≤ 4 μg mL).

Cationic Peptides and Their Cu(II) and Ni(II) Complexes: Coordination and Biological Characteristics.

Antimicrobial peptides are a promising group of compounds used for the treatment of infections. In some cases, metal ions are essential to activate these molecules. Examples of metalloantibiotics are, for instance, bleomycin and dermcidin.

Antifungal Activity of Linear and Disulfide-Cyclized Ultrashort Cationic Lipopeptides Alone and in Combination with Fluconazole against Vulvovaginal spp.

Vulvovaginal candidiasis (VVC) occurs in over 75% of women at least once during their lifetime and is an infection that significantly affects their health. strains resistant to standard azole antifungal therapy and relapses of VVC are more and more common. Hypothetically, biofilm is one of the main reasons of relapses and failure of the therapy.

The Antimicrobial Activity of Omiganan Alone and In Combination against Isolated from Vulvovaginal Candidiasis and Bloodstream Infections.

Fungi from the genus are widespread commensals and, at the same time, are the leading cause of fungal infections worldwide. For instance, vulvovaginal candidiasis (VVC) affects approximately 75% of women at least once in their lifetime, remaining the second most common gynecological infection. On the contrary, hospital-acquired fungal bloodstream infections (BSIs), although less frequent, are characterized by a high mortality rate.

Biological and Physico-Chemical Characteristics of Arginine-Rich Peptide Gemini Surfactants with Lysine and Cystine Spacers.

Ultrashort cationic lipopeptides (USCLs) and gemini cationic surfactants are classes of potent antimicrobials. Our recent study has shown that the branching and shortening of the fatty acids chains with the simultaneous addition of a hydrophobic -terminal amino acid in USCLs result in compounds with enhanced selectivity. Here, this approach was introduced into arginine-rich gemini cationic surfactants.

Anticandidal Activity of Omiganan and Its Retro Analog Alone and in Combination with Fluconazole.

Vulvovaginal candidiasis (VVC) is a vaginal infection that manifests itself as several symptoms which can lead to various life-threatening complications. The majority of VVC is caused by Candida albicans strains, and it is estimated that approximately 75% of women worldwide would suffer from this condition at least once during their lifetime. Surprisingly, the detailed pathomechanism of yeast-like fungi invasions in vagina is not yet fully understood.

The Role of Counter-Ions in Peptides-An Overview.

Peptides and proteins constitute a large group of molecules that play multiple functions in living organisms. In conjunction with their important role in biological processes and advances in chemical approaches of synthesis, the interest in peptide-based drugs is still growing. As the side chains of amino acids can be basic, acidic, or neutral, the peptide drugs often occur in the form of salts with different counter-ions.

Effect of Disulfide Cyclization of Ultrashort Cationic Lipopeptides on Antimicrobial Activity and Cytotoxicity.

Ultrashort cationic lipopeptides (USCLs) are considered to be a promising class of antimicrobials with high activity against a broad-spectrum of microorganisms. However, the majority of these compounds are characterized by significant toxicity toward human cells, which hinders their potential application. To overcome those limitations, several approaches have been advanced.

In Vitro Efficiency of Antimicrobial Peptides against Staphylococcal Pathogens Associated with Canine Pyoderma.

The emergence of staphylococcal canine pathogens resistant to multiple antimicrobial agents is a growing and urgent problem in veterinary practice. Antimicrobial peptides (AMPs) seem to be a promising alternative to conventional antibiotics. The aim of this in vitro study was to evaluate the antimicrobial activity of selected AMPs against pathogenic staphylococcal strains, including multidrug- and methicillin-resistant strains isolated from canine pyoderma cases.

Lipidated Analogs of the LL-37-Derived Peptide Fragment KR12-Structural Analysis, Surface-Active Properties and Antimicrobial Activity.

An increasing number of multidrug-resistant pathogens is a serious problem of modern medicine and new antibiotics are highly demanded. In this study, different n-alkyl acids (C-C) and aromatic acids (benzoic and -cinnamic) were conjugated to the -terminus of KR12 amide. The effect of this modification on antimicrobial activity (ESKAPE bacteria and biofilm of ) and cytotoxicity (human red blood cells and HaCaT cell line) was examined.

Ultrashort Cationic Lipopeptides-Effect of -Terminal Amino Acid and Fatty Acid Type on Antimicrobial Activity and Hemolysis.

Ultrashort cationic lipopeptides (USCLs) are promising antimicrobial agents that hypothetically may be alternatively used to combat pathogens such as bacteria and fungi. In general, USCLs consist of fatty acid chains and a few basic amino acid residues. The main shortcoming of USCLs is their relatively high cytotoxicity and hemolytic activity.

Effect of self-assembly on antimicrobial activity of double-chain short cationic lipopeptides.

Short cationic antimicrobial lipopeptides with surfactant-like structure are promising antibiotic candidates that preferentially target microbial membranes. Therefore, we focused our study on double-chain lipopeptides, (C)Dab-KKK-NH and (C)Dap-KKK-NH, where Dab and Dap are 2,4-diaminobutyric and 2,3-diaminopropionic acids, respectively. We tried to answer a question how the self-assembly behaviour affects biological activities of the tested compounds.

Influence of Short Cationic Lipopeptides with Fatty Acids of Different Chain Lengths on Bacterial Biofilms Formed on Polystyrene and Hydrogel Surfaces.

Nowadays, biomaterials are applied in many different branches of medicine. They significantly improve the patients' comfort and quality of life, but also constitute a significant risk factor for biofilm-associated infections. Currently, intensive research on the development of novel materials resistant to microbial colonization as well as new compounds that are active against biofilms is being carried out.