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Summary: Background: Insulin resistance (IR) is an important risk factor for multiple chronic diseases, increasing mortality and reducing life expectancy. The associations between emerging surrogates for IR, triglyceride-glucose index (TyG) and TyG-related indicators, with all-cause mortality and life expectancy in middle-aged and older patients in primary care are unclear. Methods: This study originated from the Polish primary care cohort LIPIDOGRAM2015, including patients aged ≥45 years. Baseline fasting triglycerides and fasting glucose were used to derive TyG. Other TyG-related indicators included TyG-adjusted body mass index (TyG-BMI), TyG-adjusted waist circumference (TyG-WC), TyG-adjusted waist-to-hip, and TyG-adjusted waist-to-height. In this longitudinal analysis, we assessed associations between TyG-related indicators with total all-cause mortality, premature (age at death ≤75 years) all-cause mortality and years of life lost (YLL). Findings: We included 10,688 patients (mean age 61.8 ± 9.3 years; 63.5% female). Cumulative total and premature all-cause mortality were 7.2% and 4.6%, respectively, during 5.7 years (IQR 5.6–5.7) of follow-up. Lowest (Q1) and highest quartile (Q4) of TyG-BMI and TyG-WC were associated with total all-cause mortality (second quartile [Q2]: reference; TyG-BMI: Q1: aHR 1.33, 95% CI 1.07–1.65, Q4: aHR 1.28, 95% CI 1.03–1.58; TyG-WC: Q1: aHR 1.44, 95% CI 1.14–1.82, Q4: aHR 1.29, 95% CI 1.04–1.59), similar results for premature all-cause mortality. Within age 45–80 years, compared with Q2 and third quartile, YLL were 4.49 and 5.46 years for TyG-BMI Q1 and Q4, respectively, 3.24 and 5.31 years for TyG-WC Q1 and Q4, respectively. Interpretation: TyG-BMI and TyG-WC demonstrated a U-shaped association with total and premature all-cause mortality. Low and high levels of TyG-BMI and TyG-WC were associated with reduced life expectancy. Despite the relatively short follow-up period, significant associations were still observed, but longer follow-up studies are required to further explore these relationships. Funding: Polish Lipid Association, College of Family Physician in Poland, Valeant in Poland.

Abstract Objective The purpose of this study was to determine the association of a multi‐pronged treatment program in emergency department (ED) patients with an acute presentation of opioid use disorder (OUD) on the rate of subsequent opioid overdose (OD). This approach included ED‐initiated take‐home naloxone, prescription buprenorphine, and an ED‐based peer support and recovery program. Methods This was a retrospective observational analysis of adult patients presenting to the ED at a large urban hospital system from November 1, 2017 to March 17, 2023. Patients with an ED discharge diagnosis of OD or OUD were included. Outcomes determined were subsequent 90‐day OD and 180‐day OD death. Post hoc analyses were performed to identify intervention utilization throughout the study period including the COVID‐19 pandemic as well as ED characteristics associated with subsequent OD and OD death. Statistical comparisons were made using logistic regression and chi‐squared test. Results A total of 2634 patients presented to the ED with an opioid OD or diagnosis of OUD. Subsequent 90‐day OD decreased significantly over time (11.5%–2.3%, odds ratio [OR] 0.85, confidence interval [CI] 0.82–0.89). No single intervention was independently associated with 90‐day OD or 180‐day OD death. Resource utilization was stable during the COVID‐19 pandemic and increased afterward. A higher buprenorphine fill‐rate among all patients and the Back race subgroup was associated with a decrease in 90‐day OD. Conclusions Subsequent OD and OD death decreased over time after implementation of a multi‐pronged treatment program to ED patients with OUD. No single intervention was associated with a decrease of subsequent OD or OD death.

Szczepan Kaliniak,1 Krzysztof Fiedoruk,2 Jakub Spałek,1,3 Ewelina Piktel,2 Bonita Durnaś,1,3 Stanisław Góźdź,1,3 Robert Bucki,2,3 Sławomir Okła1,3 1Holy-Cross Cancer Center, Kielce, Poland; 2Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, Białystok, Poland; 3Institute of Medical Science, Collegium Medicum, Jan Kochanowski University of Kielce, Kielce, 25-317, PolandCorrespondence: Sławomir Okła, Department of Otolaryngology, Head and Neck Surgery, Holy-Cross Cancer Center, Kielce, 25-734, Poland, Tel/Fax +48 41 367 43 36, Email laryngologsco@gmail.comAbstract: Rhinosinusitis (RS) is an acute (ARS) or chronic (CRS) inflammatory disease of the nasal and paranasal sinus mucosa. CRS is a heterogeneous condition characterized by distinct inflammatory patterns (endotypes) and phenotypes associated with the presence (CRSwNP) or absence (CRSsNP) of nasal polyps. Mucosal barrier and mucociliary clearance dysfunction, inflammatory cell infiltration, mucus hypersecretion, and tissue remodeling are the hallmarks of CRS. However, the underlying factors, their priority, and the mechanisms of inflammatory responses remain unclear. Several hypotheses have been proposed that link CRS etiology and pathogenesis with host (eg, “immune barrier”) and exogenous factors (eg, bacterial/fungal pathogens, dysbiotic microbiota/biofilms, or staphylococcal superantigens). The abnormal interplay between these factors is likely central to the pathophysiology of CRS by triggering compensatory immune responses. Here, we discuss the role of the sinonasal microbiota in CRS and its biofilms in the context of mucosal zinc (Zn) deficiency, serving as a possible unifying link between five host and “bacterial” hypotheses of CRS that lead to sinus mucosa remodeling. To date, no clear correlation between sinonasal microbiota and CRS has been established. However, the predominance of Corynebacteria and Staphylococci and their interspecies relationships likely play a vital role in the formation of the CRS-associated microbiota. Zn-mediated “nutritional immunity”, exerted via calprotectin, alongside the dysregulation of Zn-dependent cellular processes, could be a crucial microbiota-shaping factor in CRS. Similar to cystic fibrosis (CF), the role of SPLUNC1-mediated regulation of mucus volume and pH in CRS has been considered. We complement the biofilms’ “mechanistic” and “mucin” hypotheses behind CRS pathogenesis with the “structural” one – associated with bacterial “corncob” structures. Finally, microbiota restoration approaches for CRS prevention and treatment are reviewed, including pre- and probiotics, as well as Nasal Microbiota Transplantation (NMT).Keywords: rhinosinusitis, chronic rhinosinusitis, nasal polyps, rhinosinusitis pathophysiology, rhinosinusitis pathophysiology, microbiota, nutritional immunity

Antimicrobial peptides (AMPs), commonly referred to as host defense peptides, are found in a wide range of organisms, including bacteria, plants, and both vertebrate and invertebrate animals. They function as an initial defense mechanism against pathogenic microorganisms, modulate immune responses, and in specific instances, confer protection against the onset of cancer. Pleurocidin (Ple) is a linear antimicrobial peptide with amphipathic α-helical conformation, isolated originally from the winter flounder (Pleuronectes americanus), notable for its wide-ranging effectiveness against both bacteria and fungi. While the majority of research on pleurocidin’s biological characteristics has primarily focused on deciphering its mechanisms of interaction with the biological membranes of pathogenic bacteria and host cells, as well as investigating its modes of killing activities, there is a growing body of evidence suggesting that pleurocidin and pleurocidin-derived analogs might be effectively employed as anti-cancer agents against breast carcinoma and leukemia due to their potent cytotoxic properties and selectivity towards cancer cells. Notably, some characteristics of pleurocidin observed in microbiological investigations of this compound could be effectively applied in examining the anti-cancer capabilities of Ple-like derivatives. This review provides a comprehensive overview of the literature on the biological activities of pleurocidin, pleurocidin-derived peptides, pleurocidin-containing hybrid peptides, and nanosystems. The primary emphasis is on elucidating the range of activities exhibited by these compounds, evaluating their potential therapeutic applications, assessing their safety profile, and identifying any limits observed thus far. This paper will also discuss potential areas for further investigation into the anti-cancer effects of Ple and its derivatives, drawing insights from microbiological research.

Piktel E, Markiewicz KH, Wilczewska AZ, et al. Int J Nanomedicine. 2020;15:4573–4589. It has been brought to the authors attention that Figure 6E showing nanosystem-mediated DNA fragmentation in DLD-1 colorectal cancer cells is a duplicate of part of Figure 3C that was previously published in the review article: Wnorowska U, Fiedoruk K, Piktel E, et al. J Nanobiotechnology. 2020;18(1):3 (https://doi.org/10.1186/s12951-019-0566-z). In addition, both Figures 5E and 6E were described with incorrect treatment conditions. Data obtained during corresponding experiments were verified; consequently, Figure 5E and 6E were updated using data from the original study. The correct Figure 5 is as follows. Figure 5 Continued. Figure 5 Anticancer activity of ceragenin CSA-131 and ceragenin-containing nanoformulations against lung carcinoma A549 cells. Increase of intracellular levels of reduced thiols in A549 cells treated with CSA-131 (grey bar), MNP@CSA-131 (red bar), CSA-131+MNP (blue bar) and MNP (yellow bar) when compared to untreated control (0 μg/mL; black bar) (A). The percentages of dead cells (black columns), PI-negative cells with low viability (dark grey columns) and healthy cells (light grey columns) in lung carcinoma cells treated with CSA-131, MNP@CSA-131, CSA-131 and MNP or naked MNPs (B). The proliferation of cancer cells treated with CSA-131 (grey squares), MNP@CSA-131 (red circles), CSA-131 + MNP (blue diamonds) and MNP (yellow inverted triangles) when compared to untreated control (black squares) estimated using resazurin-based fluorimetric method (C). Induction of apoptosis in A549 cells by CSA-131 and its magnetic derivatives (D). Percentage of early apoptotic (black columns), late apoptotic/dead cells (dark grey columns) and dead cells (light grey columns). For the purpose of the clarity of the presented data, live cells (Annexin V-negative and 7-AAD-negative) were not presented in the provided figures. Morphological alternations in nuclei of A549 cells upon treatment with CSA-131, MNP@CSA-131 and CSA-131 + MNP when compared to uncreated cells (E). White arrows indicate treatment-induced morphological changes in nuclei of treated cells. All experiments were performed using agents at a concentration of 10 μg/mL for 24 h. (A–D) demonstrate results from 3 to 6 individual experiments ± SD, for panel E results from one representative experiment are shown. * and ^ indicate statistical significance (p-value

Abstract Background Plasma gelsolin (pGSN) is an important part of the blood actin buffer that prevents negative consequences of possible F-actin deposition in the microcirculation and has various functions during host immune response. Recent reports reveal that severe COVID-19 correlates with reduced levels of pGSN. Therefore, using an in vitro system, we investigated whether pGSN could attenuate increased permeability of the blood–brain barrier (BBB) during its exposure to the portion of the SARS-CoV-2 spike protein containing the receptor binding domain (S1 subunit). Materials and methods Two- and three-dimensional models of the human BBB were constructed using the human cerebral microvascular endothelial cell line hCMEC/D3 and exposed to physiologically relevant shear stress to mimic perfusion in the central nervous system (CNS). Trans-endothelial electrical resistance (TEER) as well as immunostaining and Western blotting of tight junction (TJ) proteins assessed barrier integrity in the presence of the SARS-CoV-2 spike protein and pGSN. The IncuCyte Live Imaging system evaluated the motility of the endothelial cells. Magnetic bead-based ELISA was used to determine cytokine secretion. Additionally, quantitative real-time PCR (qRT-PCR) revealed gene expression of proteins from signaling pathways that are associated with the immune response. Results pGSN reversed S1-induced BBB permeability in both 2D and 3D BBB models in the presence of shear stress. BBB models exposed to pGSN also exhibited attenuated pro-inflammatory signaling pathways (PI3K, AKT, MAPK, NF-κB), reduced cytokine secretion (IL-6, IL-8, TNF-α), and increased expression of proteins that form intercellular TJ (ZO-1, occludin, claudin-5). Conclusion Due to its anti-inflammatory and protective effects on the brain endothelium, pGSN has the potential to be an alternative therapeutic target for patients with severe SARS-CoV-2 infection, especially those suffering neurological complications of COVID-19.

Abstract Ceragenins (CSAs) are synthetic, lipid-based molecules that display activities of natural antimicrobial peptides. Previous studies demonstrated their high in vitro activity against pathogens causing urinary tract infections (UTIs), but their efficiency in vivo was not explored to date. In this study, we aimed to investigate the bactericidal efficiency of ceragenins against E. coli (Xen14 and clinical UPEC strains) isolates both in vitro and in vivo, as well to explore CSA-13 biodistribution and ability to modulate nanomechanical alterations of infected tissues using animal model of UTI. CSA-44, CSA-131 and particularly CSA-13 displayed potent bactericidal effect against tested E. coli strains, and this effect was mediated by induction of oxidative stress. Biodistribution studies indicated that CSA-13 accumulates in kidneys and liver and is eliminated with urine and bile acid. We also observed that ceragenin CSA-13 reverses infection-induced alterations in mechanical properties of mouse bladders tissue, which confirms the preventive role of CSA-13 against bacteria-induced tissue damage and potentially promote the restoration of microenvironment with biophysical features unfavorable for bacterial growth and spreading. These data justify the further work on employment of CSA-13 in the treatment of urinary tract infections.

Ensuring proper dental hygiene is of paramount importance for individuals’ general well-being, particularly for patients receiving medical care. There is a prevailing utilization of conventional oral hygiene items, including toothbrushes and mouthwashes, which have gained widespread acceptance; nevertheless, their limitations encourage investigating novel options in this domain. Our study indicates that ceragenins (CSAs) being lipid analogs of host defense peptides, well-recognized for their wide-ranging antimicrobial properties, may be a potentially efficacious means to augment oral hygiene in hospitalized individuals. We demonstrate that ceragenins CSA-13, CSA-44, and CSA-131 as well as undescribed to date CSA-255 display potent antimicrobial activities against isolates of fungi, aerobic, and anaerobic bacteria from Candida, Streptococcus, Enterococcus, and Bacteroides species, which are well-recognized representatives of microbes found in the oral cavity. These effects were further confirmed against mono- and dual-species fungal and bacterial biofilms. While the ceragenins showed similar or slightly diminished efficacy compared to commercially available mouthwashes, they demonstrated a highly favorable toxicity profile toward host cells, that may translate into better maintenance of host mucosal membrane stability. This suggests that incorporating ceragenins into oral hygiene products could be a valuable strategy for reducing the risk of both oral cavity-localized and secondary systemic infections and for improving the overall health outcomes of individuals receiving medical treatment.

Acne vulgaris (AV) is a chronic inflammatory condition of the pilosebaceous units characterized by multiple immunologic, metabolic, hormonal, genetic, psycho-emotional dysfunctions, and skin microbiota dysbiosis. The latter is manifested by a decreased population (phylotypes, i.e., genetically distinct bacterial subgroups that play different roles in skin health and disease) diversity of the predominant skin bacterial commensal - Cutinbacterium acnes. Like in other dysbiotic disorders, an elevated expression of endogenous antimicrobial peptides (AMPs) is a hallmark of AV. AMPs, such as human β-defensins, cathelicidin LL-37, dermcidin, or RNase-7, due to their antibacterial and immunomodulatory properties, function as the first line of defense and coordinate the host-microbiota interactions. Therefore, AMPs are potential candidates for pharmaceutical prophylaxis or treating this condition. This study outlines the current knowledge regarding the importance of AMPs in AV pathomechanism in light of recent transcriptomic studies. In particular, their role in improving the tight junctions (TJs) skin barrier by activating the fundamental cellular proteins, such as PI3K, GSK-3, aPKC, and Rac1, is discussed. We hypothesized that the increased expression of AMPs and their patterns in AV act as a compensatory mechanism to protect the skin with an impaired permeability barrier. Therefore, AMPs could be key determinants in regulating AV development and progression, linking acne-associated immune responses and metabolic factors, like insulin/IGF-1 and PI3K/Akt/mTOR/FoxO1 signaling pathways or glucotoxicity. Research and development of anti-acne AMPs are also addressed. [ABSTRACT FROM AUTHOR]

Oral diseases, both acute and chronic, of infectious or non-infectious etiology, represent some of the most serious medical problems in dentistry. Data from the literature increasingly indicate that changes in the oral microbiome, and therefore, the overgrowing of pathological microflora, lead to a variety of oral-localized medical conditions such as caries, gingivitis, and periodontitis. In recent years, compelling research has been devoted to the use of natural antimicrobial peptides as therapeutic agents in the possible treatment of oral diseases. This review focuses on the potential of ceragenins (CSAs), which are lipid analogs of natural antimicrobial peptides, as molecules for the development of new methods for the prevention and treatment of oral diseases. Studies to date indicate that ceragenins, with their spectrum of multidirectional biological activities, including antimicrobial, tissue regeneration-stimulating, anti-inflammatory, and immunomodulatory properties, are strong candidates for further development of oral formulations. However, many of the beneficial properties of ceragenins require confirmation in experimental conditions reproducing the oral environment to fully determine their application potential. Their transition to practical use also requires more advanced testing of these molecules in clinical trials, which have only been conducted in limited numbers to date. [ABSTRACT FROM AUTHOR]

Background/Objectives: Bacterial vaginosis (BV), an infection caused primarily by Gardnerella vaginalis, is the most prevalent vaginal infection. Although BV is often characterized by an asymptomatic course, it can lead to considerable health complications. Currently, BV therapy choices are limited, and available treatments are complicated by concerns about antibiotic resistance. Ceragenins, which together comprise an innovative class of low molecular-weight, cholic acid-based antibacterial agents, have emerged as potential alternatives to conventional treatments. Methods: This study investigates (i) the antibacterial activity of ceragenins against G. vaginalis in in vitro experimental settings at varied pH, and (ii) the effectiveness and anti-inflammatory properties of CSA-13 in a G. vaginalis-induced bacterial vaginosis animal model. Results and Conclusions: We demonstrate that ceragenins, particularly CSA-13, maintain their antibacterial efficacy throughout pH range of 4.5–7, with the highest activity observed at neutral pH (7.0). Additionally, in an animal model, beneficial effects of ceragenins are attributed to anti-inflammatory properties of these compounds, making these compounds promising agents as potential new treatment options against G. vaginalis-associated vaginal infections. [ABSTRACT FROM AUTHOR]

The growing number of infections caused by multidrug-resistant bacterial strains, limited treatment options, multi-species infections, high toxicity of the antibiotics used, and an increase in treatment costs are major challenges for modern medicine. To remedy this, scientists are looking for new antibiotics and treatment methods that will effectively eradicate bacteria while continually developing different resistance mechanisms. Ceragenins are a new group of antimicrobial agents synthesized based on molecular patterns that define the mechanism of antibacterial action of natural antibacterial peptides and steroid-polyamine conjugates such as squalamine. Since ceragenins have a broad spectrum of antimicrobial activity, with little recorded ability of bacteria to develop a resistance mechanism that can bridge their mechanism of action, there are high hopes that this group of molecules can give rise to a new family of drugs effective against bacteria resistant to currently used antibiotics. Experimental data suggests that core-shell nanosystems, in which ceragenins are presented to bacterial cells on metallic nanoparticles, may increase their antimicrobial potential and reduce their toxicity. However, studies should be conducted, among others, to assess potential long-term cytotoxicity and in vivo studies to confirm their activity and stability in animal models. Here, we summarized the current knowledge on ceragenins and ceragenin-containing nanoantibiotics as potential new tools against emerging Gram-negative rods associated with nosocomial infections.

The usage of nanotechnology in the fight against parasitic diseases is in the early stages of development, but it brings hopes that this new field will provide a solution to target the early stages of parasitosis, compensate for the lack of vaccines for most parasitic diseases, and also provide new treatment options for diseases in which parasites show increased resistance to current drugs. The huge physicochemical diversity of nanomaterials developed so far, mainly for antibacterial and anti-cancer therapies, requires additional studies to determine their antiparasitic potential. When designing metallic nanoparticles (MeNPs) and specific nanosystems, such as complexes of MeNPs, with the shell of attached drugs, several physicochemical properties need to be considered. The most important are: size, shape, surface charge, type of surfactants that control their dispersion, and shell molecules that should assure specific molecular interaction with targeted molecules of parasites’ cells. Therefore, it can be expected that the development of antiparasitic drugs using strategies provided by nanotechnology and the use of nanomaterials for diagnostic purposes will soon provide new and effective methods of antiparasitic therapy and effective diagnostic tools that will improve the prevention and reduce the morbidity and mortality caused by these diseases.

OBJECTIVES: Hyperkalemia is a common life-threatening condition causing severe electrophysiologic derangements and arrhythmias. The beneficial effects of calcium (Ca2+) treatment for hyperkalemia have been attributed to "membrane stabilization," by restoration of resting membrane potential (RMP). However, the underlying mechanisms remain poorly understood. Our objective was to investigate the mechanisms underlying adverse electrophysiologic effects of hyperkalemia and the therapeutic effects of Ca2+ treatment. DESIGN: Controlled experimental trial. SETTING: Laboratory investigation. SUBJECTS: Canine myocytes and tissue preparations. INTERVENTIONS AND MEASUREMENTS: Optical action potentials and volume averaged electrocardiograms were recorded from the transmural wall of ventricular wedge preparations (n = 7) at baseline (4 mM potassium), hyperkalemia (8-12 mM), and hyperkalemia + Ca2+ (3.6 mM). Isolated myocytes were studied during hyperkalemia (8 mM) and after Ca2+ treatment (6 mM) to determine cellular RMP. MAIN RESULTS: Hyperkalemia markedly slowed conduction velocity (CV, by 67% +/- 7%; p < 0.001) and homogeneously shortened action potential duration (APD, by 20% +/- 10%; p < 0.002). In all preparations, this resulted in QRS widening and the "sine wave" pattern observed in severe hyperkalemia. Ca2+ treatment restored CV (increase by 44% +/- 18%; p < 0.02), resulting in narrowing of the QRS and normalization of the electrocardiogram, but did not restore APD. RMP was significantly elevated by hyperkalemia; however, it was not restored with Ca2+ treatment suggesting a mechanism unrelated to "membrane stabilization." In addition, the effect of Ca2+ was attenuated during L-type Ca2+ channel blockade, suggesting a mechanism related to Ca2+-dependent (rather than normally sodium-dependent) conduction. CONCLUSIONS: These data suggest that Ca2+ treatment for hyperkalemia restores conduction through Ca2+-dependent propagation, rather than restoration of membrane potential or "membrane stabilization." Our findings provide a mechanistic rationale for Ca2+ treatment when hyperkalemia produces abnormalities of conduction (i.e. QRS prolongation). [ABSTRACT FROM AUTHOR]

Although the antineoplastic activity of metformin (MET) is well established, the underlying mechanism of the activity is not understood. Since MET activates AMP kinase (AMPK) and proline dehydrogenase/proline oxidase (PRODH/POX) is stimulated by AMPK ligands (implicated in the regulation of cancer cell survival/apoptosis), the effect of MET on PRODH/POX-dependent apoptosis in wild-type MCF-7 cells (MCF-7WT) and POX knockdown MCF-7 cells (MCF-7crPOX cells) was studied. PRODH/POX catalyzes proline degradation generating ROS-induced apoptosis or autophagy. Availability of proline for PRODH/POX functions is regulated by the activity of prolidase (enzyme releasing proline from imidodipeptides), collagen biosynthesis (process consuming proline), and metabolism of proline, ornithine, and glutamic acid. We have found that MET is cytotoxic for MCF-7 cells (IC50∼17 mM), and to the lower extent for MCF-7crPOX cells (IC50∼28 mM). In MCF-7WT cells, the effect was accompanied by the inhibition of DNA biosynthesis, collagen biosynthesis, stimulation of ROS formation, AMPKα phosphorylation, and expression of prolidase, p53, caspase 8, caspase 9, and cleaved PARP. In MET-treated MCF-7crPOX cells, the processes were less affected than in MCF-7WT cells and the expression of caspase 9 was decreased, while cleaved caspase 8 and cleaved PARP were not detected. The effects were accompanied by an increase in the prolidase activity and proline concentration. The mechanism for MET-induced apoptosis involves the up-regulation of prolidase activity and a decrease in collagen biosynthesis contributing to an increase in the concentration of substrate (proline) for PRODH/POX-dependent ROS formation and activation of caspases −9 and −8. The data suggest that PRODH/POX participates in the MET-induced intrinsic and extrinsic apoptosis in MCF-7 cells.

Ewelina Piktel,1 Karolina H Markiewicz,2 Agnieszka Z Wilczewska,2 Tamara Daniluk,1 Sylwia Chmielewska,1 Katarzyna Niemirowicz-Laskowska,1 Joanna Mystkowska,3 Paulina Paprocka,4 Paul B Savage,5 Robert Bucki1,4 1Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Bialystok, Bialystok 15-222, Poland; 2Faculty of Chemistry, University of Bialystok, Bialystok 15-245, Poland; 3Department of Materials and Biomedical Engineering, Białystok University of Technology, Białystok 15-351, Poland; 4Department of Microbiology and Immunology, The Faculty of Medicine and Health Sciences, Jan Kochanowski University in Kielce, Kielce 25-317, Poland; 5Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84604, USACorrespondence: Robert Bucki Email buckirobert@gmail.comBackground: Therapeutic efficiency of ceragenins against cancers may be limited by lack of their hemocompatibility when high concentrations of molecules are required to reach a desired result. Synergistic effects observed upon administration of anticancer agents and metal nanoparticles may provide an opportunity to limit toxicity of immobilized ceragenins on the surface of metal nanoparticles and to improve their therapeutic efficiency at the same time. The aim of present work is to investigate the anticancer activities and hemocompatibility of nanoformulations consisting of ceragenin CSA-131 united with aminosilane-modified iron oxide-based magnetic nanoparticles (MNP) and prepared by 1) covalent bonding (MNP@CSA-131) or 2) by combining CSA-131 with MNP in 1:1 ratio (CSA-131 + MNP). Possible synergistic interactions between CSA-131 and magnetic nanoparticles were also quantified.Methods: MNP@CSA-131 and CSA-131+MNP were tested in vitro against selected lung and colon cancer cells using colorimetric, fluorimetric and flow cytometry methods.Results: Performed analysis demonstrates that MNP-based nanosystems significantly improve the killing efficiency of tested ceragenin, decreasing the viability of extra 1.37± 4.72% to 76.07± 15.30% cancer cells when compared to free CSA-131. Quantification of synergistic effects indicates the favorable interactions between CSA-131 and magnetic nanoparticles (CI < 1 for all tested doses), revealing at the same time a reduction in effective doses of ceragenin from 1.17 ± 0.61 to 34.57 ± 12.78 times when combined with MNP. We demonstrate that both MNP@CSA-131 and CSA-131+MNP induce significantly apoptosis of cancer cells and prevent the division of colon cancer cells even at relatively low doses of the active compound (10 μg/mL). Importantly, combining CSA-131 with MNP decreases the hemolytic activity of free ceragenin 4.72 to 7.88 times, which indicates a considerable improvement of hemotoxicity profile.Conclusion: Comparative analyses have revealed that both developed CSA-containing nanoformulations due to the utility of synergistic interactions between MNP and CSA-131, which are effective against lung and colon cancer cells. This indicates the new directions in preparation of MNP-based therapeutics, which are relatively easy to synthetize, cost-effective and safe when intravenously administrated.Keywords: ceragenins, anticancer activity, colon cancer, lung cancer, synergistic effects, combinatory therapy

Abstract Nanotechnology-based therapeutic approaches have attracted attention of scientists, in particular due to the special features of nanomaterials, such as adequate biocompatibility, ability to improve therapeutic efficiency of incorporated drugs and to limit their adverse effects. Among a variety of reported nanomaterials for biomedical applications, metal and metal oxide-based nanoparticles offer unique physicochemical properties allowing their use in combination with conventional antimicrobials and as magnetic field-controlled drug delivery nanocarriers. An ever-growing number of studies demonstrate that by combining magnetic nanoparticles with membrane-active, natural human cathelicidin-derived LL-37 peptide, and its synthetic mimics such as ceragenins, innovative nanoagents might be developed. Between others, they demonstrate high clinical potential as antimicrobial, anti-cancer, immunomodulatory and regenerative agents. Due to continuous research, knowledge on pleiotropic character of natural antibacterial peptides and their mimics is growing, and it is justifying to stay that the therapeutic potential of nanosystems containing membrane active compounds has not been exhausted yet.

Abstract Background Magnetic nanoparticles (MNPs) are characterized by unique physicochemical and biological properties that allow their employment as highly biocompatible drug carriers. Gelsolin (GSN) is a multifunctional actin-binding protein involved in cytoskeleton remodeling and free circulating actin sequestering. It was reported that a gelsolin derived phosphoinositide binding domain GSN 160–169, (PBP10 peptide) coupled with rhodamine B, exerts strong bactericidal activity. Results In this study, we synthesized a new antibacterial and antifungal nanosystem composed of MNPs and a PBP10 peptide attached to the surface. The physicochemical properties of these nanosystems were analyzed by spectroscopy, calorimetry, electron microscopy, and X-ray studies. Using luminescence based techniques and a standard killing assay against representative strains of Gram-positive (Staphylococcus aureus MRSA Xen 30) and Gram-negative (Pseudomonas aeruginosa Xen 5) bacteria and against fungal cells (Candida spp.) we demonstrated that magnetic nanoparticles significantly enhance the effect of PBP10 peptides through a membrane-based mode of action, involving attachment and interaction with cell wall components, disruption of microbial membrane and increased uptake of peptide. Our results also indicate that treatment of both planktonic and biofilm forms of pathogens by PBP10-based nanosystems is more effective than therapy with either of these agents alone. Conclusions The results show that magnetic nanoparticles enhance the antimicrobial activity of the phosphoinositide-binding domain of gelsolin, modulate its mode of action and strengthen the idea of its employment for developing the new treatment methods of infections.

Abstract Background Urinary tract infections (UTIs) are one of the most common bacterial infections. High recurrence rates and the increasing antibiotic resistance among uropathogens constitute a large social and economic problem in current public health. We assumed that combination of treatment that includes the administration ceragenins (CSAs), will reinforce the effect of antimicrobial LL-37 peptide continuously produced by urinary tract epithelial cells. Such treatment might be an innovative approach to enhance innate antibacterial activity against multidrug-resistant E. coli. Methods Antibacterial activity measured using killing assays. Biofilm formation was assessed using crystal violet staining. Viability of bacteria and bladder epithelial cells subjected to incubation with tested agents was determined using MTT assays. We investigated the effects of chosen molecules, both alone and in combinations against four clinical strains of E. coli, obtained from patients diagnosed with recurrent UTI. Results We observed that the LL-37 peptide, whose concentration increases at sites of urinary infection, exerts increased bactericidal effect against E. coli when combined with ceragenins CSA-13 and CSA-131. Conclusion We suggest that the employment of combination of natural peptide LL-37 with synthetic analogs might be a potential solution to treat urinary tract infections caused by drug-resistant bacteria.

Abstract Background Human plasma gelsolin (pGSN) is a multifunctional actin-binding protein involved in a variety of biological processes, including neutralization of pro-inflammatory molecules such as lipopolysaccharide (LPS) and lipoteichoic acid (LTA) and modulation of host inflammatory response. It was found that PBP10, a synthetic rhodamine B-conjugated peptide, based on the phosphoinositide-binding site of pGSN, exerts bactericidal activity against Gram-positive and Gram-negative bacteria, interacts specifically with LPS and LTA, and limits microbial-induced inflammatory effects. The therapeutic efficiency of PBP10 when immobilized on the surface of iron oxide-based magnetic nanoparticles was not evaluated, to date. Results Using the human keratinocyte cell line HaCaT stimulated by bacterially-derived LPS and LTA as an in vitro model of bacterial infection, we examined the anti-inflammatory effects of nanosystems consisting of iron oxide-based magnetic nanoparticles with aminosilane (MNP@NH2) or gold shells (MNP@Au) functionalized by a set of peptides, derived from the phosphatidylinositol 4,5-bisphosphate (PIP2)-binding site of the human plasma protein gelsolin, which also binds LPS and LTA. Our results indicate that these nanosystems can kill both Gram-positive and Gram-negative bacteria and limit the production of inflammatory mediators, including nitric oxide (NO), reactive oxygen species (ROS), and interleukin-8 (IL-8) in the response to heat-killed microbes or extracted bacterial cell wall components. The nanoparticles possess the potential to improve therapeutic efficacy and are characterized by lower toxicity and improved hemocompatibility when compared to free peptides. Atomic force microscopy (AFM) showed that these PBP10-based nanosystems prevented changes in nanomechanical properties of cells that were otherwise stimulated by LPS. Conclusions Neutralization of endotoxemia-mediated cellular effects by gelsolin-derived peptides and PBP10-containing nanosystems might be considered as potent therapeutic agents in the improved therapy of bacterial infections and microbial-induced inflammation.

Oral leukoplakia is a clinical term relating to various morphological lesions, including squamous cell hyperplasia, dysplasia and carcinoma. Leukoplakia morphologically manifested as hyperplasia with epithelial dysplasia is clinically treated as precancerous condition. Nevertheless, there is a lack of good markers indicating the transformation of premalignancies towards cancer. A better understanding of the mechanical environment within the tissues where tumors grow might be beneficial for the development of prevention, diagnostic, and treatment methods in cancer management. Atomic force microscopy (AFM) and immunohistology techniques were used to assess changes in the stiffness and morphology of oral mucosa and leukoplakia samples at different stages of their progression towards cancer. The Young's moduli of the tested leukoplakia samples were significantly higher than those of the surrounding mucus. Robust inhomogeneity of stiffness within leukoplakia samples, reflecting an increase in regeneration and collagen accumulation (increasing density) in the extracellular matrix (ECM), was observed. Within the histologically confirmed cancer samples, Young's moduli were significantly lower than those within the precancerous ones. Inhomogeneous stiffness within leukoplakia might act as “a mechanoagonist” that promotes oncogenesis. In contrast, cancer growth might require the reorganization of tissue structure to create a microenvironment with lower and homogenous stiffness. The immunohistology data collected here indicates that changes in tissue stiffness are achieved by increasing cell/ECM density. The recognition of new markers of premalignancy will aid in the development of new therapies and will expand the diagnostic methods.

Background Amiodarone is administered during resuscitation, but its antiarrhythmic effects during targeted temperature management are unknown. The purpose of this study was to determine the effect of both therapeutic hypothermia and amiodarone on arrhythmia substrates during resuscitation from cardiac arrest. Methods and Results We utilized 2 complementary models: (1) In vitro no‐flow global ischemia canine left ventricular transmural wedge preparation. Wedges at different temperatures (36°C or 32°C) were given 5 µmol/L amiodarone (36‐Amio or 32‐Amio, each n=8) and subsequently underwent ischemia and reperfusion. Results were compared with previous controls. Optical mapping was used to measure action potential duration, dispersion of repolarization (DOR), and conduction velocity (CV). (2) In vivo pig model of resuscitation. Pigs (control or targeted temperature management, 32–34°C) underwent ischemic cardiac arrest and were administered amiodarone (or not) after 8 minutes of ventricular fibrillation. In vitro: therapeutic hypothermia but not amiodarone prolonged action potential duration. During ischemia, DOR increased in the 32‐Amio group versus 32‐Alone (84±7 ms versus 40±7 ms, P