Pseudomonas aeruginosa is an adaptable organism, frequently found in chronic infections, and for which antimicrobial resistance is a growing concern. Therefore, there is an urgent need for alternative therapeutic strategies. Cationic antimicrobial peptides (AMPs) offer potent bactericidal activity but suffer from limited selectivity and potential host toxicity. To enhance species-specific targeting, we designed two prodrug variants of the AMP D-Bac8CLeu2,5─EEEE-D-Bac8CLeu2,5 and ELEG-D-Bac8CLeu2,5─engineered for activation by the P. aeruginosa extracellular aminopeptidase PaAP. While both prodrug motifs effectively neutralized the positive charge of D-Bac8CLeu2,5 and prevented DNA-peptide complex formation, EEEE-D-Bac8CLeu2,5 showed negligible antimicrobial activity due to slow and incomplete activation. In contrast, ELEG-D-Bac8CLeu2,5 underwent rapid PaAP-mediated activation, restoring bactericidal activity in planktonic cultures and biofilms. PaAP contributed significantly to complete prodrug activation, particularly within biofilms, where the accumulation of partially activated intermediates correlated with biphasic killing kinetics. The prodrug showed reduced activity against other ESKAPEE pathogens, demonstrating selective activation by P. aeruginosa. Experiments selecting resistant bacteria revealed distinct mutations in lipopolysaccharide biosynthesis pathways for D-Bac8CLeu2,5 and the prodrug, with limited cross-resistance. These findings establish aminopeptidase-activated AMP prodrugs as a promising approach for species-selective antimicrobial therapy and highlight the feasibility of exploiting bacterial enzymes for controlled antimicrobial peptide activation.

To identify pancoronaviral inhibitors, we sought to identify peptides that bound the evolutionarily conserved SARS-CoV-2 spike fusion peptide (FP). We screened the NEB PhD-7-mer random combinatorial phage display library against FP, synthesised as a D-peptide, to identify peptides from the L-library to be synthesised as proteolytically resistant D peptides. We selected the top ten peptides that were not seen in another published screen with this library, as these were more likely to be specific. All ten D-peptides had no impact on the infection of Vero-E6/TMPRSS2 cells by SARS-CoV-2. Screening of a proteomic-derived phage display library from the disordered regions of human proteins identified two overlapping 14mer peptides from a region of OTUD1. While a synthetic peptide based on their sequences failed to markedly inhibit viral entry, molecular dynamics structural modelling highlighted a stable binding mode where positive residues on one side of the OTUD1 helix interacted with hydrophobic residues of the FP triple-helical wedge. Thus, while the two phage display strategies failed to yield peptide sequences that are themselves strong inhibitors of viral infection, they led to the development of a computational model that can underpin future designs of potential pancoronaviral FP disruptors.

Antiviral peptides derived from the heptad region of RNA viral entry proteins inhibit both retroviral and coronaviral fusion in vivo. Another key region for SARS-CoV-2 fusion is the evolutionarily conserved fusion peptide (FP), motivating us to identify peptides that bind FP and might inhibit viral entry across coronaviruses. We screened the NEB PhD-7mer random combinatorial phage display library against FP, synthesised as a D-peptide. This strategy was used to identify peptides from the L-library that could then be synthesised as proteolytically resistant D peptides. We selected the top seven peptides that were not seen in another published screen with this library, as these were more likely to be specific. All seven D-peptides had no impact on the infection of Vero-E6/TMPRSS2 cells by SARS-CoV-2. We also screened a proteomic derived phage display library from the disordered regions of human proteins. Two overlapping peptides were identified from a region of OTUD1, which is known to influence various viral infections. However, a synthetic peptide based on their sequences failed to markedly inhibit viral entry. Thus, while two alternative phage display screening strategies identified potential binding peptides, none of these peptides in their current forms represented strong candidates for direct viral inhibition.

Introduction:Acute and chronic wound infections involving biofilms and caused by antimicrobial resistant (AMR) pathogens present significant challenges in healthcare, leading to substantial patient morbidity, increased hospital stays, and rising healthcare costs. Novel antimicrobial therapies are urgently needed to address these infections. Methods:A screening of multiple antimicrobial peptides (AMPs) was performed and the most potent candidate, D-Bac8c2,5 Leu, was tested against monospecies and polymicrobial biofilms of Staphylococcus aureus and Pseudomonas aeruginosa using static and dynamic in vitro models. Cytotoxicity was evaluated on human cell lines, and the peptide was incorporated into a methylcellulose hydrogel to assess sustained release and antimicrobial efficacy as a hydrogel dressing. Results:D-Bac8c2,5 Leu significantly reduced biofilm viability in both monospecies and polymicrobial biofilms. In static biofilm assays, treatment led to a 2-3 log reduction in bacterial load compared to untreated controls. In Duckworth biofilm flow device, a similar reduction was observed, demonstrating efficacy in conditions mimicking wound environments. Furthermore, D-Bac8c2,5 Leu exhibited low cytotoxicity against human cell lines, and its incorporation into a methylcellulose hydrogel facilitated sustained release and enhanced antimicrobial activity. Furthermore, the peptide-loaded hydrogel showed considerable efficacy in disrupting pre-formed biofilms, underscoring its potential as a novel treatment for acute and chronic wound infections. Discussion:These findings highlight the potential of D-Bac8c2,5 Leu to help address the urgent need for effective therapies against AMR pathogens and biofilm-associated wound infections. Further studies should focus on in vivo efficacy to optimize its therapeutic application in wound care.

Cationic amphipathic poly(ethylene glycol)-based polymers are generated with synthetic efficiencies allowing their evaluation as antimicrobial peptide (AMP) mimetics. Accordingly, statistical copolymers with cationic units consistently functionalized with guanyl groups, but different side-chain lengths, and hydrophobic units displaying long aliphatic, branched, and/or aromatic side chains are produced and tested for their antimicrobial and hemolytic properties. The results obtained indicate that candidates with activities and selectivity commensurate to some AMPs can be obtained and that further development of this novel type of antimicrobial peptidomimetics, pegtides, is warranted for clinical and/or biotechnological applications.

Background: Gain(1q) is among the most frequent high-risk cytogenetic abnormalities in multiple myeloma (MM), closely linked with treatment resistance, disease progression, and the development of extramedullary disease (EMD). The F11R gene, encoding Junctional Adhesion Molecule-A (JAM-A), is located on chromosome 1q. Beyond adhesive function, JAM-A drives oncogenic signalling via cis-dimerization, promoting proliferation, survival, motility, and dissemination of cancer cells. This study aims to functionally validate JAM-A as a driver of MM progression and to develop a second-generation peptide inhibitor that disrupts JAM-A cis-dimerization, with the aim of impairing MM cell proliferation, adhesion to the bone marrow (BM) niche, invasion and tumour formation. Methods: F11R expression and associations with cytogenetic risk and survival were analysed using the CoMMpass IA20 dataset. Functional studies included siRNA JAM-A knockdown in JAM-A–high KMS18 cells and JAM-A overexpression in JAM-A–low MM1S cells. JAM-A protein levels were confirmed by Western blot; proliferation was assessed using CyQuant assays. A structure-guided peptide library was designed to improve binding affinity and stability to the JAM-A cis-dimer interface. Candidates were screened for anti-proliferative activity in MM cell lines and primary CD138+ patient-derived cells. Mechanistic assays included β-galactosidase senescence, adhesion to HS5 stromal cells and invasion assays using transwell inserts to identify and validate a lead compound. Peptide specificity was confirmed by using JAM-A knockdown cells. The lead peptide was further evaluated in vivo using the chick chorioallantoic membrane (CAM) model, a rapid and cost-effective xenograft platform developed by our lab (PMID: 35267611) to rapidly screen novel therapies in vivo. This model supports the growth of “plasmacytoma like” tumours from MM cells. KMS18 cells were pre-treated with 200 µM of lead peptide prior to implantation. Tumours were grown for four days; tumour burden was quantified macroscopically and by immunohistochemistry for Ki67 and CD138. Results: Median F11R expression was significantly (p<0.0001) higher in MM patients with gain(1q) (9.61 TPM, n=396) compared to those without (7.138 TPM, n=396 and progressively increased from healthy donors through to relapsed MM (RRMM) (mean healthy: 48.4 vs RRMM: 87.83, p=0.0425) High JAM-A expression was associated with inferior progression-free survival (JAM-A low: 1106 days vs JAM-A high: 914 days, p=0.0516) and overall survival (JAM-A low: 2922 days vs JAM-A high: 2356 days, p=0.0009). Functional studies demonstrated that JAM-A overexpression promotes proliferation: (54% increased in over-expressing cells versus empty vector controls, p=0.0152, (MM1S n=2). From the novel peptide library designed, a peptide termed P4 emerged as the most potent inhibitor of MM cell growth (KMS18 p=0.037, n=4), and reduced proliferation in patient-derived CD138+ cells (n=5). P4 both induced senescence and significantly reduced MM cell adhesion to HS5 stromal cells (untreated: 100% vs P4 treated:71.28%, p=0.0024, n=3), consistent with the adhesive role of JAM-A. Pre-treatment with P4 reduced tumour burden in the CAM model (n=2). Pre-treated tumour xenografts were macroscopically reduced in size and tumour mass (mean: untreated 1.13g vs mean: pre-treated: 0.28g p=<0.0001), with reductions in Ki67 proliferation index and CD138+ plasma cell content. Conclusion: JAM-A is overexpressed in 1q amplified HR-MM patients and may represent a novel target for this group of patients. Our data suggests that a novel peptide targeting JAM-A may be effective in reducing MM cell proliferation and impairing adhesion to stromal cells. These findings support further preclinical development of JAM-A–targeting strategies in MM.

Combination of peptide conjugation and peptide mimetic techniques produces a selective antibacterial molecule from two broad spectrum antimicrobials.

Cationic antimicrobial peptides (AMPs), also called host defence peptides, have established antimicrobial and anticancer activities. Conjugation of an AMP to a bioactive molecule with complementary activity can address some of the clinical limitations of the peptide candidate. This approach has been particularly applied in antimicrobial applications of AMPs, but it remains relatively less explored in the generation of anticancer candidates. In this study, two usnic acid derivatives, based on hydrazinothiazole and benzylidenefuranone pharmacophore moieties, respectively, were conjugated to L-K6, a lysine/leucine-rich AMP, through a new pyrazole ligation intrinsically driven by the cargo molecule. Both components, the usnic acid derivative and the peptide, are selectively active against cancer cells, by targeting the human DNA repair enzyme tyrosyl-DNA phosphodiesterase 1 (TDP1) and through DNA damage, respectively. The two conjugates, based on a hydrazone linkage, exhibited pleiotropic effects, ranging from reduction in the activity of the parent drugs to their conservation or even enhancement. Notably, the conjugates retained some anti-TDP1 activity and displayed intermediate, or even higher, cytotoxicities against glioblastoma cells, compared to their individual components.

The common cold is generally considered a usually harmless infectious disease of the upper respiratory pathway, with mostly mild symptoms. However, it should not be overlooked, as a severe cold can lead to serious complications, resulting in hospitalization or death in vulnerable patients. The treatment of the common cold remains purely symptomatic. Analgesics as well as oral antihistamines or decongestants may be advised to relieve fever, and local treatments can clear the airways and relieve nasal congestion, rhinorrhea, or sneezing. Certain medicinal plant specialties can be used as therapy or as complementary self-treatment. Recent scientific advances discussed in more detail in this review have demonstrated the plant’s efficiency in the treatment of the common cold. This review presents an overview of plants used worldwide in the treatment of cold diseases.

Internationalisation, as well as the need to interact with international partners in academia and in the pharmaceutical industry, brings an international experience to the pharmacist's career, which is essential. The objective of present work is to provide a preliminary study of the current situation of the pre-professional mobility of pharmacy students. It represents the first case study of the international pre-professional mobility of pharmacy students in France, and in north-eastern France in particular. The study is based on a recent preliminary survey among pharmacy students, conducted in 2020 at the University of Lorraine's Faculty of Pharmacy, reflecting the impact of international mobility programmes, such as the European Union educational and training mobility programme Erasmus+, on the pharmacy curriculum. The results of the present work tend to show that, despite a number of barriers to the international mobility of pharmacy students, the outcomes of international pre-professional mobility are rather positive in their globality.

:antimicrobial peptides (AMPs) are widely studiedas therapeutic agents due to their broad-spectrum efficacy againstinfections. However, their clinical use is hampered by the low invivo bioavailability and systemic toxicity. Such limitations might beovercome by using appropriate drug delivery systems. Here, thepreparation of a drug delivery system (DDS) by physicalconjugation of an arginine-rich peptide and hydrothermal carbonnanoparticles (CNPs) has been explored, and its antimicrobialefficacy againstEschericia coli(E. coli) andStaphylococcus aureusinvestigated in comparison with the unloaded carrier and the freepeptide. The mechanism of interaction between CNPs and thebacteria was investigated by scanning electron microscopy and acombined dielectrophoresis-Raman spectroscopy method for real-time analysis. In view of a possible systemic administration, theeffect of proteins on the stability of the DDS was investigated by using albumin as a model protein. The peptide was boundedelectrostatically to the CNPs surface, establishing an equilibrium modulated by pH and albumin. The DDS exhibited antimicrobialactivity toward the two bacterial strains, albeit lower as compared to the free peptide. The decrease in effectiveness towardE. coliwaslikely due to the rapid formation of a particle-induced extracellular matrix. The present results are relevant for the futuredevelopment of hydrothermal CNPs as drug delivery agents of AMPs.

Breast ductal carcinoma in situ (DCIS) is clinically challenging, featuring high diagnosis rates and few targeted therapies. Expression/signaling from junctional adhesion molecule-A (JAM-A) has been linked to poor prognosis in invasive breast cancers, but its role in DCIS is unknown. Since progression from DCIS to invasive cancer has been linked with overexpression of the human epidermal growth factor receptor-2 (HER2), and JAM-A regulates HER2 expression, we evaluated JAM-A as a therapeutic target in DCIS. JAM-A expression was immunohistochemically assessed in patient DCIS tissues. A novel JAM-A antagonist (JBS2) was designed and tested alone/in combination with the HER2 kinase inhibitor lapatinib, using SUM-225 cells in vitro and in vivo as validated DCIS models. Murine tumors were proteomically analyzed. JAM-A expression was moderate/high in 96% of DCIS patient tissues, versus 23% of normal adjacent tissues. JBS2 bound to recombinant JAM-A, inhibiting cell viability in SUM-225 cells and a primary DCIS culture in vitro and in a chick embryo xenograft model. JBS2 reduced tumor progression in in vivo models of SUM-225 cells engrafted into mammary fat pads or directly injected into the mammary ducts of NOD-SCID mice. Preliminary proteomic analysis revealed alterations in angiogenic and apoptotic pathways. High JAM-A expression in aggressive DCIS lesions and their sensitivity to treatment by a novel JAM-A antagonist support the viability of testing JAM-A as a novel therapeutic target in DCIS.

Numerous studies have led to a better understanding of the mechanisms of action of viruses in systemic infections for the development of prevention strategies and very promising antiviral therapies. Viruses still remain one of the main causes of human diseases, mainly because the development of new vaccines is usually challenging and drug resistance has become an increasing concern in recent decades. Therefore, the development of potential antiviral agents remains crucial and is an unmet clinical need. One abundant source of potential therapeutic molecules are plants: they biosynthesize a myriad of compounds, including peptides which can have antimicrobial activity. Our objective is to summarize the literature on peptides with antiviral properties derived from plants and to identify key features of these peptides and their application in systemic viral infections. This literature review highlights studies including clinical trials which demonstrated that plant cyclotides have the ability to inhibit the growth of viruses causing human diseases, defensin-like peptides possess anti-HIV-1 activity, and lipid transfer proteins and some lectins exhibit a varied antimicrobial profile. To conclude, plant peptides remain interesting to explore in the context of emerging and re-emerging infectious diseases.

Human gastroenteritis viruses are amid the major causes of disease worldwide, responsible for more than 2 million deaths per year. Human noroviruses play a leading role in the gastroenteritis outbreaks and the continuous emergence of new strains contributes to the significant morbidity and mortality. Many aspects of the viral entry and infection process remain unclear, including the major response of the host cell to the virus, which is the trigger of several programmed cell death related mechanisms. In this review, we assessed apoptosis and autophagy at various stages in the infection process to provide better understanding of the viral-host interaction. This brings us closer to fully understanding how noroviruses work, thus allowing the development of specific antiviral therapies.

The degree of resin swelling in a particular solvent system is one of the critical parameters for solid-phase peptide synthesis (SPPS) and for solid-phase synthesis in general. Methods used for measuring the degree of resin swelling include microscopy-based and volumetry-based methods. This study describes and compares the use of both methods for a number of commercially available resins commonly used in SPPS, with a range of solvents, which have been identified in the literature as 'greener' than DCM, DMF and NMP. The results were analysed by statistical methods, and a significant correlation between the two distinct methods has been demonstrated for the first time. The results will likely be used, in conjunction with other literature methods, to help in choosing both the resin and solvent system for greener SPPS, as well as for continuous flow SPPS, which is of growing importance.