Remodeling of Paranasal Sinuses Mucosa Functions in Response to Biofilm-Induced Inflammation

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).

Ceragenin-mediated disruption of Pseudomonas aeruginosa biofilms

BACKGROUND

Microbial biofilms, as a hallmark of cystic fibrosis (CF) lung disease and other chronic infections, remain a desirable target for antimicrobial therapy. These biopolymer-based viscoelastic structures protect pathogenic organisms from immune responses and antibiotics. Consequently, treatments directed at disrupting biofilms represent a promising strategy for combating biofilm-associated infections. In CF patients, the viscoelasticity of biofilms is determined mainly by their polymicrobial nature and species-specific traits, such as Pseudomonas aeruginosa filamentous (Pf) bacteriophages. Therefore, we examined the impact of microbicidal ceragenins (CSAs) supported by mucolytic agents-DNase I and poly-aspartic acid (pASP), on the viability and viscoelasticity of mono- and bispecies biofilms formed by Pf-positive and Pf-negative P. aeruginosa strains co-cultured with Staphylococcus aureus or Candida albicans.

METHODS

The in vitro antimicrobial activity of ceragenins against P. aeruginosa in mono- and dual-species cultures was assessed by determining minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC/MFC). Inhibition of P. aeruginosa mono- and dual-species biofilms formation by ceragenins alone and in combination with DNase I or poly-aspartic acid (pASP) was estimated by the crystal violet assay. Additionally, the viability of the biofilms was measured by colony-forming unit (CFU) counting. Finally, the biofilms' viscoelastic properties characterized by shear storage (G') and loss moduli (G"), were analyzed with a rotational rheometer.

RESULTS

Our results demonstrated that ceragenin CSA-13 inhibits biofilm formation and increases its fluidity regardless of the Pf-profile and species composition; however, the Pf-positive biofilms are characterized by elevated viscosity and elasticity parameters.

CONCLUSION

Due to its microbicidal and viscoelasticity-modifying properties, CSA-13 displays therapeutic potential in biofilm-associated infections, especially when combined with mucolytic agents.

Efficacy of Ceragenins in Controlling the Growth of Oral Microorganisms: Implications for Oral Hygiene Management

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.

Ceragenins and Ceragenin-Based Core-Shell Nanosystems as New Antibacterial Agents against Gram-Negative Rods Causing Nosocomial Infections

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.

Ceragenins exhibit antiviral activity against SARS-CoV-2 by increasing the expression and release of type I interferons upon activation of the host's immune response

The COVID-19 pandemic caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) heavily burdened the entire world socially and economically. Despite a generation of vaccines and therapeutics to confront infection, it remains a threat. Most available antivirals target viral proteins and block their activity or function. While such an approach is considered effective and safe, finding treatments for specific viruses of concern leaves us unprepared for developed resistance and future viral pandemics of unknown origin. Here, we propose ceragenins (CSAs), synthetic amphipathic molecules designed to mimic the properties of cationic antimicrobial peptides (cAMPs), as potential broad-spectrum antivirals. We show that selected CSAs exhibit antiviral activity against SARS-CoV-2 and low-pathogenic human coronaviruses 229E, OC43, and NL63. The mechanism of action of CSAs against coronaviruses is mainly attributed to the stimulation of antiviral cytokines, such as type I interferons or IL-6. Our study provides insight into a novel immunomodulatory strategy that might play an essential role during the current pandemic and future outbreaks.

Metallic Nanoparticles and Core-Shell Nanosystems in the Treatment, Diagnosis, and Prevention of Parasitic Diseases

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.

Metallic Nanosystems in the Development of Antimicrobial Strategies with High Antimicrobial Activity and High Biocompatibility

Antimicrobial resistance is a major and growing global problem and new approaches to combat infections caused by antibiotic resistant bacterial strains are needed. In recent years, increasing attention has been paid to nanomedicine, which has great potential in the development of controlled systems for delivering drugs to specific sites and targeting specific cells, such as pathogenic microbes. There is continued interest in metallic nanoparticles and nanosystems based on metallic nanoparticles containing antimicrobial agents attached to their surface (core shell nanosystems), which offer unique properties, such as the ability to overcome microbial resistance, enhancing antimicrobial activity against both planktonic and biofilm embedded microorganisms, reducing cell toxicity and the possibility of reducing the dosage of antimicrobials. The current review presents the synergistic interactions within metallic nanoparticles by functionalizing their surface with appropriate agents, defining the core structure of metallic nanoparticles and their use in combination therapy to fight infections. Various approaches to modulate the biocompatibility of metallic nanoparticles to control their toxicity in future medical applications are also discussed, as well as their ability to induce resistance and their effects on the host microbiome.

Recombinant human plasma gelsolin reverses increased permeability of the blood-brain barrier induced by the spike protein of the SARS-CoV-2 virus

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.

Metformin Induces PRODH/POX-Dependent Apoptosis in Breast Cancer Cells

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-7^WT) and POX knockdown MCF-7 cells (MCF-7^crPOX 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-7^crPOX cells (IC50∼28 mM). In MCF-7^WT 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-7^crPOX cells, the processes were less affected than in MCF-7^WT 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.

N-Acetyl-Cysteine Increases Activity of Peanut-Shaped Gold Nanoparticles Against Biofilms Formed by Clinical Strains of Pseudomonas aeruginosa Isolated from Sputum of Cystic Fibrosis Patients

Background

Extracellular polymeric substances (EPS) produced by bacteria, as they form a biofilm, determine the stability and viscoelastic properties of biofilms and prevent antibiotics from penetrating this multicellular structure. To date, studies demonstrated that an appropriate optimization of the chemistry and morphology of nanotherapeutics might provide a favorable approach to control their interaction with EPS and/or diffusion within the biofilm matrix. Targeting the biofilms’ EPS, which in certain conditions can adopt liquid crystal structure, was demonstrated to improve the anti-biofilm activity of antibiotics and nanoparticles. A similar effect is achievable by interfering EPS’ production by mucoactive agents, such as N-acetyl-cysteine (NAC). In our previous study, we demonstrated the nanogram efficiency of non-spherical gold nanoparticles, which due to their physicochemical features, particularly morphology, were noted to be superior in antimicrobial activity compared to their spherical-shaped counterparts.

Methods

To explore the importance of EPS matrix modulation in achieving a suitable efficiency of peanut-shaped gold nanoparticles (AuP NPs) against biofilms produced by Pseudomonas aeruginosa strains isolated from cystic fibrosis patients, fluorescence microscopy, as well as resazurin staining were employed. Rheological parameters of AuP NPs-treated biofilms were investigated by rotational and creep-recovery tests using a rheometer in a plate-plate arrangement.

Results

We demonstrated that tested nanoparticles significantly inhibit the growth of mono- and mixed-species biofilms, particularly when combined with NAC. Notably, gold nanopeanuts were shown to decrease the viscosity and increase the creep compliance of Pseudomonas biofilm, similarly to EPS-targeting NAC. Synergistic activity of AuP NPs with tobramycin was also observed, and the AuP NPs were able to eradicate bacteria within biofilms formed by tobramycin-resistant isolates.

Conclusion

We propose that peanut-shaped gold nanoparticles should be considered as a potent therapeutic agent against Pseudomonas biofilms.

Extracellular Vimentin as a Target Against SARS-CoV-2 Host Cell Invasion

Infection of human cells by pathogens, including SARS-CoV-2, typically proceeds by cell surface binding to a crucial receptor. The primary receptor for SARS-CoV-2 is the angiotensin-converting enzyme 2 (ACE2), yet new studies reveal the importance of additional extracellular co-receptors that mediate binding and host cell invasion by SARS-CoV-2. Vimentin is an intermediate filament protein that is increasingly recognized as being present on the extracellular surface of a subset of cell types, where it can bind to and facilitate pathogens' cellular uptake. Biophysical and cell infection studies are done to determine whether vimentin might bind SARS-CoV-2 and facilitate its uptake. Dynamic light scattering shows that vimentin binds to pseudovirus coated with the SARS-CoV-2 spike protein, and antibodies against vimentin block in vitro SARS-CoV-2 pseudovirus infection of ACE2-expressing cells. The results are consistent with a model in which extracellular vimentin acts as a co-receptor for SARS-CoV-2 spike protein with a binding affinity less than that of the spike protein with ACE2. Extracellular vimentin may thus serve as a critical component of the SARS-CoV-2 spike protein-ACE2 complex in mediating SARS-CoV-2 cell entry, and vimentin-targeting agents may yield new therapeutic strategies for preventing and slowing SARS-CoV-2 infection.

Hypogelsolinemia and Decrease in Blood Plasma Sphingosine-1-Phosphate in Patients Diagnosed with Severe Acute Pancreatitis

BACKGROUND

Acute pancreatitis (AP) is a frequent hospitalization cause of patients suffering from gastrointestinal disorders. Gelsolin has an ability to bind bioactive lipids including different sphingolipids engaged in inflammatory response. Importantly, hypogelsolinemia was observed in patients with different states of acute and chronic inflammation.

AIMS

The aim of the present study was to assess the interplay of blood plasma gelsolin and blood plasma sphingosine-1-phosphate (S1P) concentration in patients diagnosed with acute pancreatitis.

MATERIALS AND METHODS

To assess the concentration of gelsolin and S1P, immunoblotting and HPLC technique were employed, respectively. Additionally, the concentrations of amylase, lipase, C-reactive protein (CRP), procalcitonin (PCT) and the number of white blood cells (WBC) and platelet (PLT) were recorded.

RESULTS

We found that both pGSN and S1P concentrations in the plasma of the AP patients were significantly lower (pGSN ~ 15-165 mg/L; S1P ~ 100-360 pmol/mL) when compared to the levels of pGSN and S1P in a control group (pGSN ~ 130-240 mg/L; S1P ~ 260-400 pmol/mL). Additionally, higher concentrations of CRP, WBC, amylase and lipase were associated with low level of gelsolin in the blood of AP patients. No correlations between the level of PCT and PLT with gelsolin concentration were noticed.

CONCLUSION

Plasma gelsolin and S1P levels decrease during severe acute pancreatitis. Simultaneous assessment of pGSN and S1P can be useful in development of more accurate diagnostic strategies for patients with severe acute pancreatitis.

Targeting bacteria causing otitis media using nanosystems containing nonspherical gold nanoparticles and ceragenins

Aim: To evaluate the antibacterial and antibiofilm activity of ceragenin-conjugated nonspherical gold nanoparticles against the most common agents of otitis media. Methods: Minimal inhibitory and bactericidal concentrations and colony-counting assays, as well as colorimetric and fluorimetric methods, were used to estimate the antibacterial activity of compounds in phosphate-buffered saline and human cerumen. The nanosystems' biocompatibility and ability to decrease IL-8 release was tested using keratinocyte cells. Results: The tested compounds demonstrated strong antimicrobial activity against planktonic and biofilm cultures at nontoxic doses due to the induction of oxidative stress followed by the damage of bacterial membranes. Conclusion: This study indicates that ceragenin-conjugated nonspherical gold nanoparticles have potential as new treatment methods for eradicating biofilm-forming pathogens associated with otitis media.

Targeting the Gut Microbiota to Relieve the Symptoms of Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a common, chronic, functional disorder with a large impact on world population. Its pathophysiology is not completely revealed; however, it is certain that dysregulation of the bidirectional communications between the central nervous system (CNS) and the gut leads to motility disturbances, visceral hypersensitivity, and altered CNS processing characterized by differences in brain structure, connectivity and functional responsiveness. Emerging evidence suggests that gut microbiota exerts a marked influence on the host during health and disease. Gut microbiome disturbances can be also important for development of IBS symptoms and its modulation efficiently contributes to the therapy. In this work, we review the current knowledge about the IBS therapy, the role of gut microbiota in pathogenesis of IBS, and we discuss that its targeting may have significant impact on the effectiveness of IBS therapy.

Ceragenin-Coated Non-Spherical Gold Nanoparticles as Novel Candidacidal Agents

BACKGROUND

Infections caused by Candida spp. have become one of the major causes of morbidity and mortality in immunocompromised patients. Therefore, new effective fungicides are urgently needed, especially due to an escalating resistance crisis.

METHODS

A set of nanosystems with rod- (AuR), peanut- (AuP), and star-shaped (AuS) metal cores were synthesized. These gold nanoparticles were conjugated with ceragenins CSA-13, CSA-44, and CSA-131, and their activity was evaluated against Candida strains (n = 21) through the assessment of MICs (minimum inhibitory concentrations)/MFCs (minimum fungicidal concentrations). Moreover, in order to determine the potential for resistance development, serial passages of Candida cells with tested nanosystems were performed. The principal mechanism of action of Au NPs was evaluated via ROS (reactive oxygen species) generation assessment, plasma membrane permeabilization, and release of the protein content. Finally, to evaluate the potential toxicity of Au NPs, the measurement of hemoglobin release from red blood cells (RBCs) was carried out.

RESULTS

All of the tested nanosystems exerted a potent candidacidal activity, regardless of the species or susceptibility to other antifungal agents. Significantly, no resistance development after 25 passages of Candida cells with AuR@CSA-13, AuR@CSA-44, and AuR@CSA-131 nanosystems was observed. Moreover, the fungicidal mechanism of action of the investigated nanosystems involved the generation of ROS, damage of the fungal cell membrane, and leakage of intracellular contents. Notably, no significant RBCs hemolysis at candidacidal doses of tested nanosystems was detected.

CONCLUSIONS

The results provide rationale for the development of gold nanoparticles of rod-, peanut-, and star-shaped conjugated with CSA-13, CSA-44, and CSA-131 as effective candidacidal agents.

Inhomogeneity of stiffness and density of the extracellular matrix within the leukoplakia of human oral mucosa as potential physicochemical factors leading to carcinogenesis

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.

Extracellular vimentin as a target against SARS-CoV-2 host cell invasion

Infection of human cells by pathogens, including SARS-CoV-2, typically proceeds by cell surface binding to a crucial receptor. In the case of SARS-CoV-2, angiotensin-converting enzyme 2 (ACE2) has been identified as a necessary receptor, but not all ACE2-expressing cells are equally infected, suggesting that other extracellular factors are involved in host cell invasion by SARS-CoV-2. Vimentin is an intermediate filament protein that is increasingly recognized as being present on the extracellular surface of a subset of cell types, where it can bind to and facilitate pathogens' cellular uptake. Here, we present evidence that extracellular vimentin might act as a critical component of the SARS-CoV-2 spike protein-ACE2 complex in mediating SARS-CoV-2 cell entry. We demonstrate direct binding between vimentin and SARS-CoV-2 pseudovirus coated with the SARS-CoV-2 spike protein and show that antibodies against vimentin block in vitro SARS-CoV-2 pseudovirus infection of ACE2-expressing cells. Our results suggest new therapeutic strategies for preventing and slowing SARS-CoV-2 infection, focusing on targeting cell host surface vimentin.

ROS-Mediated Apoptosis and Autophagy in Ovarian Cancer Cells Treated with Peanut-Shaped Gold Nanoparticles

Background

Even with considerable improvement in treatment of epithelial ovarian cancer achieved in recent years, an increasing chemotherapy resistance and disease 5-year relapse is recorded for a majority part of patients that encourages the search for better therapeutic options. Gold nanoparticles (Au NPs) due to plethora of unique physiochemical features are thoroughly tested as drug delivery, radiosensitizers, as well as photothermal and photodynamic therapy agents. Importantly, due to highly controlled synthesis, it is possible to obtain nanomaterials with directed size and shape.

Methods

In this work, we developed novel elongated-type gold nanoparticles in the shape of nanopeanuts (AuP NPs) and investigated their cytotoxic potential against ovarian cancer cells SKOV-3 using colorimetric and fluorimetric methods, Western blot, flow cytometry, and fluorescence microscopy.

Results

Peanut-shaped gold nanoparticles showed high anti-cancer activity in vitro against SKOV-3 cells at doses of 1–5 ng/mL upon 72 hours treatment. We demonstrate that AuP NPs decrease the viability and proliferation capability of ovarian cancer cells by triggering cell apoptosis and autophagy, as evidenced by flow cytometry and Western blot analyses. The overproduction of reactive oxygen species (ROS) was noted to be a critical mediator of AuP NPs-mediated cell death.

Conclusion

These data indicate that gold nanopeanuts might be developed as nanotherapeutics against ovarian cancer.

Physics Comes to the Aid of Medicine-Clinically-Relevant Microorganisms through the Eyes of Atomic Force Microscope

Despite the hope that was raised with the implementation of antibiotics to the treatment of infections in medical practice, the initial enthusiasm has substantially faded due to increasing drug resistance in pathogenic microorganisms. Therefore, there is a need for novel analytical and diagnostic methods in order to extend our knowledge regarding the mode of action of the conventional and novel antimicrobial agents from a perspective of single microbial cells as well as their communities growing in infected sites, i.e., biofilms. In recent years, atomic force microscopy (AFM) has been mostly used to study different aspects of the pathophysiology of noninfectious conditions with attempts to characterize morphological and rheological properties of tissues, individual mammalian cells as well as their organelles and extracellular matrix, and cells’ mechanical changes upon exposure to different stimuli. At the same time, an ever-growing number of studies have demonstrated AFM as a valuable approach in studying microorganisms in regard to changes in their morphology and nanomechanical properties, e.g., stiffness in response to antimicrobial treatment or interaction with a substrate as well as the mechanisms behind their virulence. This review summarizes recent developments and the authors’ point of view on AFM-based evaluation of microorganisms’ response to applied antimicrobial treatment within a group of selected bacteria, fungi, and viruses. The AFM potential in development of modern diagnostic and therapeutic methods for combating of infections caused by drug-resistant bacterial strains is also discussed.

Rod-shaped gold nanoparticles exert potent candidacidal activity and decrease the adhesion of fungal cells

Aim: To investigate the fungicidal activity of rod-shaped gold nanoparticles (AuR NPs) against Candida strains isolated from hematooncological patients and representative strains of filamentous fungi. Methods: Colony-counting assays, colorimetric and fluorometric methods and atomic force microscopy were employed. Results: AuR NPs were characterized by their potent fungicidal activity against all tested isolates, regardless of the species or drug susceptibility, at concentrations that are nontoxic to the host cells. The membrane-permeabilizing properties of AuR NPs and induction of reactive oxygen species were recognized as crucial for fungicidal activity. Conclusions: The results provide a rationale for the development of nonspherical Au NPs as effective antifungals or drug-delivery carriers to improve therapy for fungal infections.

Two Lineages of Pseudomonas aeruginosa Filamentous Phages: Structural Uniformity over Integration Preferences

Pseudomonas aeruginosa filamentous (Pf) bacteriophages are important factors contributing to the pathogenicity of this opportunistic bacterium, including biofilm formation and suppression of bacterial phagocytosis by macrophages. In addition, the capacity of Pf phages to form liquid crystal structures and their high negative charge density makes them potent sequesters of cationic antibacterial agents, such as aminoglycoside antibiotics or host antimicrobial peptides. Therefore, Pf phages have been proposed as a potential biomarker for risk of antibiotic resistance development. The majority of studies describing biological functions of Pf viruses have been performed with only three of them: Pf1, Pf4, and Pf5. However, our analysis revealed that Pf phages exist as two evolutionary lineages (I and II), characterized by substantially different structural/morphogenesis properties, despite sharing the same integration sites in the host chromosomes. All aforementioned model Pf phages are members of the lineage I. Hence, it is reasonable to speculate that their interactions with P. aeruginosa and impact on its pathogenicity may be not completely extrapolated to the lineage II members. Furthermore, in order to organize the present numerical nomenclature of Pf phages, we propose a more informative approach based on the insertion sites, that is, Pf-tRNA-Gly, -Met, -Sec, -tmRNA, and -DR (direct repeats), which are fully compatible with one of five types of tyrosine integrases/recombinases XerC/D carried by these viruses. Finally, we discuss possible evolutionary mechanisms behind this division and consequences from the perspective of virus-virus, virus-bacterium, and virus-human interactions.

NDM-1 Carbapenemase-Producing Enterobacteriaceae are Highly Susceptible to Ceragenins CSA-13, CSA-44, and CSA-131

Background and Purpose

Treatment of infections caused by NDM-1 carbapenemase-producing Enterobacteriaceae (CPE) represents one of the major challenges of modern medicine. In order to address this issue, we tested ceragenins (CSAs – cationic steroid antimicrobials) as promising agents to eradicate various NDM-1-producing Gram-negative enteric rods.

Materials and Methods

Susceptibility to CSA-13, CSA-44, and CSA-131 of four reference NDM-1 carbapenemase-producing strains, ie, Escherichia coli BAA-2471, Enterobacter cloacae BAA-2468, Klebsiella pneumoniae subsp. pneumoniae BAA-2472, and K. pneumoniae BAA-2473 was assessed by MIC/MBC testing of planktonic cells as well as biofilm formation/disruption assays. To define the mechanism of CSAs bactericidal activity, their ability to induce generation of reactive oxygen species (ROS), permeabilization of the inner and outer membranes, and their mechanical and adhesive properties upon CSA addition were examined. Additionally, hemolytic assays were performed to assess CSAs hemocompatibility.

Results

All tested CSAs exert substantial bactericidal activity against NDM-1-producing bacteria. Moreover, CSAs significantly prevent biofilm formation as well as reduce the mass of developed biofilms. The mechanism of CSA action comprises both increased permeability of the outer and inner membrane, which is associated with an extensive ROS generation. Additionally, atomic force microscopy (AFM) analysis has shown morphological alterations in bacterial cells and the reduction of stiffness and adhesion properties. Importantly, CSAs are characterized by low hemolytic activity at concentrations that are bactericidal.

Conclusion

Development of ceragenins should be viewed as one of the valid strategies to provide new treatment options against infections associated with CPE. The studies presented herein demonstrate that NDM-1-positive bacteria are more susceptible to ceragenins than to conventional antibiotics. In effect, CSA-13, CSA-44, and CSA-131 may be favorable for prevention and decrease of global burden of CPE.

Quantification of Synergistic Effects of Ceragenin CSA-131 Combined with Iron Oxide Magnetic Nanoparticles Against Cancer Cells

BACKGROUND

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.

Recombinant Human Plasma Gelsolin Stimulates Phagocytosis while Diminishing Excessive Inflammatory Responses in Mice with Pseudomonas aeruginosa Sepsis

Plasma gelsolin (pGSN) is a highly conserved abundant circulating protein, characterized by diverse immunomodulatory activities including macrophage activation and the ability to neutralize pro-inflammatory molecules produced by the host and pathogen. Using a murine model of Gram-negative sepsis initiated by the peritoneal instillation of Pseudomonas aeruginosa Xen 5, we observed a decrease in the tissue uptake of IRDye^®800CW 2-deoxyglucose, an indicator of inflammation, and a decrease in bacterial growth from ascitic fluid in mice treated with intravenous recombinant human plasma gelsolin (pGSN) compared to the control vehicle. Pretreatment of the murine macrophage line RAW264.7 with pGSN, followed by addition of Pseudomonas aeruginosa Xen 5, resulted in a dose-dependent increase in the proportion of macrophages with internalized bacteria. This increased uptake was less pronounced when cells were pretreated with pGSN and then centrifuged to remove unbound pGSN before addition of bacteria to macrophages. These observations suggest that recombinant plasma gelsolin can modulate the inflammatory response while at the same time augmenting host antibacterial activity.

Nanoantibiotics containing membrane-active human cathelicidin LL-37 or synthetic ceragenins attached to the surface of magnetic nanoparticles as novel and innovative therapeutic tools: current status and potential future applications

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.

Expression and Function of Host Defense Peptides at Inflammation Sites

There is a growing interest in the complex role of host defense peptides (HDPs) in the pathophysiology of several immune-mediated inflammatory diseases. The physicochemical properties and selective interaction of HDPs with various receptors define their immunomodulatory effects. However, it is quite challenging to understand their function because some HDPs play opposing pro-inflammatory and anti-inflammatory roles, depending on their expression level within the site of inflammation. While it is known that HDPs maintain constitutive host protection against invading microorganisms, the inducible nature of HDPs in various cells and tissues is an important aspect of the molecular events of inflammation. This review outlines the biological functions and emerging roles of HDPs in different inflammatory conditions. We further discuss the current data on the clinical relevance of impaired HDPs expression in inflammation and selected diseases.

Toxicity of parasites and their unconventional use in medicine

INTRODUCTION

Over 300 species of parasites can possibly be passed on humans. Most of the parasitic infections are defined based on their pathogenicity; however, some positive effects of a parasite existence within the human body have recently been suggested. Beneficial outcomes of parasite infections might result from the production and release of metabolites, modification of host immune response or products uptake of the host.

OBJECTIVE

The aim of the study was a comprehensive analysis of a wide range of effects of parasites on the human body, including an overview of the toxic and positive effects.

STATE OF KNOWLEDGE

In the light of the latest research presenting the unconventional use of parasites in medicine, the widely understood of their impact on the human body can also be considered in a positive context. Clinical cases from diseases caused by the toxic effects of parasites, as described in recent years, indicate that the problem of parasitic infections still persists. Despite a great deal of knowledge about the toxic effects of parasites on the human organism and, above all, despite the improvement in sanitary conditions, there is a resurgence of parasitic infections, as evidenced, e.g. by the examples presented in this review.

CONCLUSIONS

The examples of positive effects of parasites presented so far give hope for the future in terms of fighting many diseases for which pharmacological treatment has not yet brought a positive effect. A better understanding of those processes might lead to the development of new methods of unconventional medical treatment.

Decreased Activity of Blood Acid Sphingomyelinase in the Course of Multiple Myeloma

Acid sphingomyelinase (aSMase) is involved in the generation of metabolites that function as part of the sphingolipid signaling pathway. It catalyzes the breakdown of sphingomyelin into ceramide, a bioactive lipid that, among other roles, is involved in regulation of apoptosis. Dry drop blood test (DBS) and colorimetric 2-step enzymatic assay were used to assess the activity of human blood aSMase, beta-galactosidase, and beta-glucosidase, these enzymes are lysosomal hydrolases that catalyze the degradation of related sphingolipids, of sphingolipid signaling molecules. Blood was collected from a group of healthy volunteers and patients that were diagnosed with multiple myeloma (MM) in various stages of the disease. Additionally, activity of those enzymes in patients diagnosed with other hematological cancers was also assessed. We found that aSMase activity in the blood of patients with MM (at the time of diagnosis) was 305.43 pmol/spot*20 h, and this value was significantly lower (p < 0.030) compared to the healthy group 441.88 pmol/spot*20 h. Our collected data suggest a possible role of aSMase in pathogenesis of MM development.

Susceptibility of microbial cells to the modified PIP2-binding sequence of gelsolin anchored on the surface of magnetic nanoparticles

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.

Use of ceragenins as a potential treatment for urinary tract infections

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.

Inhibition of inflammatory response in human keratinocytes by magnetic nanoparticles functionalized with PBP10 peptide derived from the PIP2-binding site of human plasma gelsolin

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.

Bactericidal and immunomodulatory properties of magnetic nanoparticles functionalized by 1,4-dihydropyridines

Background

1,4-Dihydropyridine (1,4-DHP) and its derivatives are well-known calcium channel blockers with antiarrhythmic and antihypertensive activities. These compounds exhibit pleiotropic effects including antimicrobial activities that rely on their positive charge and amphipathic nature. Use of magnetic nanoparticles (MNPs) as carriers of 1,4-DHP modulates their properties and enables improved formulations with higher efficacy and less toxicity.

Methods

In this study, the antimicrobial and immunomodulatory activities of novel 1,4-DHP derivatives in free form and immobilized on MNPs were determined by evaluating pathogen outgrowth and proinflammatory cytokine release in experimental settings that involve incubation of various 1,4-DHPs with clinical isolates of bacteria or fungi as well as mammalian cell culture models.

Results

Conventional immobilization of 1,4-DHP on aminosilane-coated MNPs markedly enhances their antimicrobial activity compared to nonimmobilized molecules, in part because of the higher affinity of these nanosystems for bacterial cell wall components in the presence of human body fluids.

Conclusion

Optimized nanosystems are characterized by improved biocompatibility and higher anti-inflammatory properties that provide new opportunities for the therapy of infectious diseases.

Targeting polyelectrolyte networks in purulent body fluids to modulate bactericidal properties of some antibiotics

The response of the human immune system to most bacterial infections results in accumulation of neutrophils at infection sites that release a significant quantity of DNA and F-actin. Both are negatively charged polyelectrolytes that can interact with positively charged host defense molecules such as cathelicidin-delivered LL-37 peptide or other cationic antibiotic agents. Evaluation of the ability of bacterial outgrowth (using luminescence measurements or counting colony-forming units) to form a biofilm (quantified by crystal violet staining) and analysis of the structure of DNA/F-actin network by optical microscopy in human pus samples treated with different antibiotics in combination with plasma gelsolin, DNAse 1, and/or poly-aspartic acid revealed that bactericidal activity of most tested antibacterial agents increases in the presence of DNA/F-actin depolymerizing factors.

Use of magnetic nanoparticles as a drug delivery system to improve chlorhexidine antimicrobial activity

Nanotechnology offers new tools for developing therapies to prevent and treat oral infections, particularly biofilm-dependent disorders, such as dental plaques and endodontic and periodontal diseases. Chlorhexidine (CHX) is a well-characterized antiseptic agent used in dentistry with broad spectrum activity. However, its application is limited due to inactivation in body fluid and cytotoxicity toward human cells, particularly at high concentrations. To overcome these limitations, we synthesized nanosystems composed of aminosilane-coated magnetic nanoparticles functionalized with chlorhexidine (MNP@CHX). In the presence of human saliva, MNPs@CHX displayed significantly greater bactericidal and fungicidal activity against planktonic and biofilm-forming microorganisms than free CHX. In addition, CHX attached to MNPs has an increased ability to restrict the growth of mixed-species biofilms compared to free CHX. The observed depolarization of mitochondria in fungal cells treated with MNP@CHX suggests that induction of oxidative stress and oxidation of fungal structures may be a part of the mechanism responsible for pathogen killing. Nanoparticles functionalized by CHX did not affect host cell proliferation or their ability to release the proinflammatory cytokine, IL-8. The use of MNPs as a carrier of CHX has great potential for the development of antiseptic nanosystems.

Development of antifungal therapies using nanomaterials

The number and diversity of chemical structures currently available as antibacterial drugs is much higher compared with the number of active substances in relation to pathogenic fungi. In this review we focus on nanotechnology approaches, which offer promising strategies to create nanoagents that possess broad-spectrum antifungal activity and might overcome mechanisms of antibiotic resistance. Special attention was given to magnetic nanoparticles and their ability to restrict fungal growth directly, which depends on surface chemistry and pathogen strains. We speculate that future developments of new antifungal methods will take advantage of the current knowledge of using of magnetic nanomaterials as anticancer agents based on their ability to induce hyperthermia and enhance photosensitizing processes.

Anaerobic bacteria growth in the presence of cathelicidin LL-37 and selected ceragenins delivered as magnetic nanoparticles cargo

BACKGROUND

Cationic antibacterial peptides (CAPs) and synthetic molecules mimicking the amphiphilic structure of CAPs, such as ceragenins, are promising compounds for the development of new antimicrobials.

RESULTS

We tested the in vitro activity of ceragenins CSA-13 and CSA-131 against several anaerobic bacteria including Bacteroides spp. and Clostridium difficile. We compared results to the activity of cathelicidin LL-37, metronidazole and nanosystems developed by attachment of CSA-13 and CSA-131 to magnetic nanoparticles (MNPs). The antibacterial effect was tested using killing assay and modified CLSI broth microdilution assay. Ceragenins CSA-13 and CSA-131 displayed stronger bactericidal activity than LL-37 or metronidazole against all of the tested bacterial strains. Additionally CSA-131 revealed an enhanced ability to prevent the formation of Bacteroides fragilis and Propionibacterium acnes biofilms.

CONCLUSIONS

These data confirmed that ceragenins display antimicrobial activity against a broad range of microorganisms including anaerobic bacteria and deserve further investigations as compounds serving to develop new treatment against anaerobic and mixed infections.

Formulation and candidacidal activity of magnetic nanoparticles coated with cathelicidin LL-37 and ceragenin CSA-13

Fungal infections caused by Candida spp. represent an emerging problem during treatment of immunocompromised patients and those hospitalized with serious principal diseases. The ever-growing number of fungal strains exhibiting drug resistance necessitates the development of novel antimicrobial therapies including those based on membrane-permeabilizing agents and nanomaterials as drug carriers. In this study, the fungicidal activities of LL-37 peptide, ceragenin CSA-13 and its magnetic derivatives (MNP@LL-37, MNP@CSA-13) against laboratory and clinical strains of C. albicans, C. glabrata and C. tropicalis were evaluated. These experiments confirm the high anti-fungal activity of these well-characterized agents mediated by their interaction with the fungal membrane and demonstrate elevated activity following immobilization of LL-37 and CSA-13 on the surface of magnetic nanoparticles (MNPs). Furthermore, MNP-based nanosystems are resistant to inhibitory factors present in body fluids and effectively inhibit formation of fungal biofilm. Simultaneously, synthesized nanostructures maintain immunomodulatory properties, described previously for free LL-37 peptide and CSA-13 substrate and they do not interfere with the proliferation and viability of osteoblasts, confirming their high biocompatibility.

Sphingosine-1-Phosphate Metabolism and Its Role in the Development of Inflammatory Bowel Disease

Beyond their role as structural molecules, sphingolipids are involved in many important cellular processes including cell proliferation, apoptosis, inflammation, and migration. Altered sphingolipid metabolism is observed in many pathological conditions including gastrointestinal diseases. Inflammatory bowel disease (IBD) represents a state of complex, unpredictable, and destructive inflammation of unknown origin within the gastrointestinal tract. The mechanisms explaining the pathophysiology of IBD involve signal transduction pathways regulating gastro-intestinal system’s immunity. Progressive intestinal tissue destruction observed in chronic inflammation may be associated with an increased risk of colon cancer. Sphingosine-1-phosphate (S1P), a sphingolipid metabolite, functions as a cofactor in inflammatory signaling and becomes a target in the treatment of IBD, which might prevent its conversion to cancer. This paper summarizes new findings indicating the impact of (S1P) on IBD development and IBD-associated carcinogenesis.

Core-shell magnetic nanoparticles display synergistic antibacterial effects against Pseudomonas aeruginosa and Staphylococcus aureus when combined with cathelicidin LL-37 or selected ceragenins

Core–shell magnetic nanoparticles (MNPs) are promising candidates in the development of new treatment methods against infections, including those caused by antibiotic-resistant pathogens. In this study, the bactericidal activity of human antibacterial peptide cathelicidin LL-37, synthetic ceragenins CSA-13 and CSA-131, and classical antibiotics vancomycin and colistin, against methicillin-resistant Staphylococcus aureus Xen 30 and Pseudomonas aeruginosa Xen 5, was assessed alone and in combination with core–shell MNPs. Fractional inhibitory concentration index and fractional bactericidal concentration index were determined by microdilution methods. The potential of combined therapy using nanomaterials and selected antibiotics was confirmed using chemiluminescence measurements. Additionally, the ability of tested agents to prevent bacterial biofilm formation was evaluated using crystal violet staining. In most conditions, synergistic or additive effects were observed when combinations of core–shell MNPs with ceragenins or classical antibiotics were used. Our study revealed that a mixture of membrane-active agents such as LL-37 peptide or ceragenin CSA-13 with MNPs potentialized their antibacterial properties and might be considered as a method of delaying and overcoming bacterial drug resistance.

Recent insights in nanotechnology-based drugs and formulations designed for effective anti-cancer therapy

The rapid development of nanotechnology provides alternative approaches to overcome several limitations of conventional anti-cancer therapy. Drug targeting using functionalized nanoparticles to advance their transport to the dedicated site, became a new standard in novel anti-cancer methods. In effect, the employment of nanoparticles during design of antineoplastic drugs helps to improve pharmacokinetic properties, with subsequent development of high specific, non-toxic and biocompatible anti-cancer agents. However, the physicochemical and biological diversity of nanomaterials and a broad spectrum of unique features influencing their biological action requires continuous research to assess their activity. Among numerous nanosystems designed to eradicate cancer cells, only a limited number of them entered the clinical trials. It is anticipated that progress in development of nanotechnology-based anti-cancer materials will provide modern, individualized anti-cancer therapies assuring decrease in morbidity and mortality from cancer diseases. In this review we discussed the implication of nanomaterials in design of new drugs for effective antineoplastic therapy and describe a variety of mechanisms and challenges for selective tumor targeting. We emphasized the recent advantages in the field of nanotechnology-based strategies to fight cancer and discussed their part in effective anti-cancer therapy and successful drug delivery.

The Role of Cathelicidin LL-37 in Cancer Development

LL-37 is a C-terminal peptide proteolytically released from 18 kDa human cathelicidin protein (hCAP18). Chronic infections, inflammation, tissue injury and tissue regeneration are all linked with neoplastic growth, and involve LL-37 antibacterial and immunomodulatory functions. Such a link points to the possible involvement of LL-37 peptide in carcinogenesis. An increasing amount of evidence suggests that LL-37 can have two different and contradictory effects--promotion or inhibition of tumor growth. The mechanisms are tissue-specific, complex, and depend mostly on the ability of LL-37 to act as a ligand for different membrane receptors whose expression varies on different cancer cells. Overexpression of LL-37 was found to promote development and progression of ovarian, lung and breast cancers, and to suppress tumorigenesis in colon and gastric cancer. This review explores and summarizes the current views on how LL-37 contributes to immunity, pathophysiology and cell signaling involved in malignant tumor growth.

Magnetic nanoparticles enhance the anticancer activity of cathelicidin LL-37 peptide against colon cancer cells

The pleiotropic activity of human cathelicidin LL-37 peptide includes an ability to suppress development of colon cancer cells. We hypothesized that the anticancer activity of LL-37 would improve when attached to the surface of magnetic nanoparticles (MNPs). Using colon cancer culture (DLD-1 cells and HT-29 cells), we evaluated the effects of MNPs, LL-37 peptide, its synthetic analog ceragenin CSA-13, and two novel nanosystems, ie, MNP@LL-37 and MNP@CSA-13, on cancer cell viability and apoptosis. Treatment of cancer cells with the LL-37 peptide linked to MNPs (MNP@LL-37) caused a greater decrease in cell viability and a higher rate of apoptosis compared with treatment using free LL-37 peptide. Additionally, we observed a strong ability of ceragenin CSA-13 and MNP@CSA-13 to induce apoptosis of DLD-1 cells. We found that both nanosystems were successfully internalized by HT-29 cells, and cathelicidin LL-37 and ceragenin CSA-13 might play a key role as novel homing molecules. These results indicate that the previously described anticancer activity of LL-37 peptide against colon cancer cells might be significantly improved using a theranostic approach.

Bactericidal activity and biocompatibility of ceragenin-coated magnetic nanoparticles

Background

Ceragenins, synthetic mimics of endogenous antibacterial peptides, are promising candidate antimicrobial agents. However, in some settings their strong bactericidal activity is associated with toxicity towards host cells. To modulate ceragenin CSA-13 antibacterial activity and biocompatibility, CSA-13-coated magnetic nanoparticles (MNP-CSA-13) were synthesized. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to characterize MNP-CSA-13 physicochemical properties. Bactericidal action and ability of these new compounds to prevent Pseudomonas. aeruginosa biofilm formation were assessed using a bacteria killing assay and crystal violet staining, respectively. Release of hemoglobin from human red blood cells was measured to evaluate MNP-CSA-13 hemolytic activity. In addition, we used surface activity measurements to monitor CSA-13 release from the MNP shell. Zeta potentials of P. aeruginosa cells and MNP-CSA-13 were determined to assess the interactions between the bacteria and nanoparticles. Morphology of P. aeruginosa subjected to MNP-CSA-13 treatment was evaluated using atomic force microscopy (AFM) to determine structural changes indicative of bactericidal activity.

Results

Our studies revealed that the MNP-CSA-13 nanosystem is stable and may be used as a pH control system to release CSA-13. MNP-CSA-13 exhibits strong antibacterial activity, and the ability to prevent bacteria biofilm formation in different body fluids. Additionally, a significant decrease in CSA-13 hemolytic activity was observed when the molecule was immobilized on the nanoparticle surface.

Conclusion

Our results demonstrate that CSA-13 retains bactericidal activity when immobilized on a MNP while biocompatibility increases when CSA-13 is covalently attached to the nanoparticle.