Search

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

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

Ewelina Piktel,1 Urszula Wnorowska,1 Joanna Depciuch,2 Dawid Łysik,3 Mateusz Cieśluk,1 Krzysztof Fiedoruk,1 Joanna Mystkowska,3 Magdalena Parlińska-Wojtan,2 Paul A Janmey,4 Robert Bucki1 1Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, Białystok, 15-222, Poland; 2Institute of Nuclear Physic, Polish Academy of Sciences, Krakow, PL-31342, Poland; 3Institute of Biomedical Engineering, Bialystok University of Technology, Bialystok, 15-351, Poland; 4Department of Physiology and Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA, 19102, USACorrespondence: Robert Bucki, Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Bialystok, Mickiewicza 2C, Bialystok, 15-222, Poland, Tel + 48 85 748 5793, Email buckirobert@gmail.comBackground: 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.Graphical Abstract: Keywords: gold nanoparticles, non-spherical nanoparticles, N-acetyl-cysteine, bacteria biofilm, cystic fibrosis, Pseudomonas aeruginosa

Paulina Paprocka,1 Bonita Durnaś,1,2 Angelika Mańkowska,1 Karol Skłodowski,3 Grzegorz Król,1 Magdalena Zakrzewska,3 Michał Czarnowski,3 Patrycja Kot,1 Kamila Fortunka,1 Stanisław Góźdź,2 Paul B Savage,4 Robert Bucki1,3 1Department of Microbiology and Immunology, Institute of Medical Science, Collegium Medicum, Jan Kochanowski University in Kielce, Kielce, Poland; 2Holy Cross Oncology Center of Kielce, Kielce, Poland; 3Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, Białystok, Poland; 4Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USACorrespondence: Robert Bucki Tel +48-85-7485493Fax +48-85 748 54 16Email buckirobert@gmail.comBackground: The increasing number of infections caused by antibiotic resistant strains of Pseudomonas aeruginosa posed a very serious challenge for clinical practice. This standing is driving scientists to develop new antibiotics against these microorganisms.Methods: In this study, we measured the MIC/MBC values and estimated the ability of tested molecules to prevent bacterial biofilm formation to explore the effectiveness of β-lactam antibiotics ceftolozane/tazobactam, ceftazidime/avibactam, meropenem/vaborbactam, and ceragenins CSA-13, CSA-44, and CSA-131 against 150 clinical isolates of Pseudomonas aeruginosa that were divided into five groups, based on their antibiotic resistance profiles to beta-lactams. Selected strains of microorganisms from each group were also subjected to prolonged incubations (20 passages) with ceragenins to probe the development of resistance towards those molecules. Cytotoxicity of tested ceragenins was evaluated using human red blood cell (RBCs) hemolysis and microscopy observations of human lung epithelial A549 cells after ceragenin treatment. Poloxamer 407 (pluronic F-127) at concentrations ranging from 0.5% to 5% was tested as a potential drug delivery substrate to reduce ceragenin toxicity.Results: Collected data proved that ceragenins at low concentrations are highly active against clinical strains of Pseudomonas aeruginosa regardless of their resistance mechanisms to conventional antibiotics. Ceragenins also show low potential for resistance development, high antibiofilm activity, and controlled toxicity when used together with poloxamer 407.Conclusion: This data strongly supports the need for further study directed to develop this group of molecules as new antibiotics to fighting infections caused by antibiotic resistant strains of Pseudomonas aeruginosa.Keywords: ceragenin, antibacterial agents, Pseudomonas aeruginosa, antibiotic resistant bacteria, new antibiotics

Ewelina Piktel,1 Ilona Ościłowska,2 Łukasz Suprewicz,1 Joanna Depciuch,3 Natalia Marcińczyk,4 Ewa Chabielska,4 Przemysław Wolak,5 Tomasz Wollny,6 Marianna Janion,5 Magdalena Parlinska-Wojtan,3 Robert Bucki1 1Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Bialystok, Bialystok, 15-222, Poland; 2Department of Medicinal Chemistry, Medical University of Bialystok, Bialystok, 15-222, Poland; 3Institute of Nuclear Physics Polish Academy of Sciences, Krakow, PL-31342, Poland; 4Department of Biopharmacy, Medical University of Bialystok, Bialystok, 15-222, Poland; 5 Institute of Medical Sciences, Collegium Medicum, Jan Kochanowski University, Kielce, 25-317, Poland; 6Holy Cross Cancer Center in Kielce, Kielce, 25-734, PolandCorrespondence: Robert BuckiDepartment of Medical Microbiology and Nanobiomedical Engineering, Medical University of Bialystok, Mickiewicza 2C, Bialystok, 15-222, PolandTel + 48 85 748 5793Email buckirobert@gmail.comBackground: 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.Keywords: gold nanoparticles, ovarian cancer, gold nanopeanuts, anti-cancer therapy, nanotechnology, apoptosis, autophagy

Mateusz Cieśluk,1 Katarzyna Pogoda,2 Piotr Deptuła,1 Paulina Werel,3 Alina Kułakowska,3 Jan Kochanowicz,3 Zenon Mariak,4 Tomasz Łysoń,4 Joanna Reszeć,5 Robert Bucki1 1Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Bialystok, Bialystok PL-15222, Poland; 2Institute of Nuclear Physics, Polish Academy of Sciences, Krakow PL-31342, Poland; 3Department of Neurology, Medical University of Bialystok, Bialystok PL-15276, Poland; 4Department of Neurosurgery, Medical University of Bialystok, Bialystok PL-15276, Poland; 5Department of Pathology, Medical University of Bialystok, Bialystok PL-15269, PolandCorrespondence: Robert BuckiDepartment of Medical Microbiology and Nanobiomedical Engineering, Medical University of Bialystok, Mickiewicza 2C, Bialystok 15-222, PolandTel +48 85 784 5483Email buckirobert@gmail.comBackground: The tissue-mechanics environment plays a crucial role in human brain physiological development and the pathogenesis of different diseases, especially cancer. Assessment of alterations in brain mechanical properties during cancer progression might provide important information about possible tissue abnormalities with clinical relevance.Methods: With atomic force microscopy (AFM), the stiffness of freshly removed human brain tumor tissue was determined on various regions of the sample and compared to the stiffness of healthy human brain tissue that was removed during neurosurgery to gain access to tumor mass. An advantage of indentation measurement using AFM is the small volume of tissue required and high resolution at the single-cell level.Results: Our results showed great heterogeneity of stiffness within metastatic cancer or primary high-grade gliomas compared to healthy tissue. That effect was not clearly visible in lower-grade tumors like meningioma.Conclusion: Collected data indicate that AFM might serve as a diagnostic tool in the assessment of human brain tissue stiffness in the process of recognizing tumors.Keywords: AFM, brain tumors, human tissue rheology, mechanomarkers, glioblastoma

Sylwia Joanna Chmielewska,1 Karol Skłodowski,1 Ewelina Piktel,1 Łukasz Suprewicz,1 Krzysztof Fiedoruk,1 Tamara Daniluk,1 Przemysław Wolak,2 Paul B Savage,3 Robert Bucki1 1Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, Białystok, Poland; 2The Faculty of Medicine and Health Sciences of the Jan Kochanowski University in Kielce, Kielce, Poland; 3Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USACorrespondence: Robert BuckiDepartment of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, Mickiewicza 2C, Białystok 15-222, PolandTel +48 85 748 5493Fax +48 85 748 5416Email buckirobert@gmail.comBackground 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.Keywords: antibiotic resistance, NDM-1, CSA-13, CSA-44, CSA-131, ceragenins, CPE

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

Katarzyna Niemirowicz-Laskowska,1 Katarzyna Głuszek,1 Ewelina Piktel,1 Karlis Pajuste,2 Bonita Durnaś,3 Grzegorz Król,3 Agnieszka Z Wilczewska,4 Paul A Janmey,5 Aiva Plotniece,2 Robert Bucki1 1Department of Microbiological and Nanobiomedical Engineering, Medical University of Bialystok, Bialystok, Poland; 2Laboratory of Membrane Active Compounds and β-Diketones, Latvian Institute of Organic Synthesis, Riga, Latvia; 3Department of Microbiology and Immunology, The Faculty of Health Sciences of the Jan Kochanowski University in Kielce, Kielce, 4Institute of Chemistry, University of Bialystok, Białystok, Poland; 5Department of Physiology, Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA, USA 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. Keywords: magnetic nanoparticles, 1,4-dihydropyridine, antibacterial, antifungal, immunomodulatory properties

Robert Bucki,1,* Bonita Durnaś,2,* Marzena Wątek,2,3 Ewelina Piktel,1 Katrina Cruz,4 Przemysław Wolak,2 Paul B Savage,5 Paul A Janmey4 1Department of Microbiological and Nanobiomedical Engineering, Medical University of Białystok, Białystok, 2Department of Microbiology and Immunology, The Faculty of Health Sciences of the Jan Kochanowski University in Kielce, 3Holy Cross Oncology Center of Kielce, Kielce, Kielce, Poland; 4Department of Physiology, Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA, 5Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA *These authors contributed equally to this work Abstract: 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. Keywords: antibiotic activity, polyelectrolyte network, depolymerizing factors, cathelicidin, ceragenins, DNase 1, cystic fibrosis

Grażyna Tokajuk,1,2 Katarzyna Niemirowicz,1 Piotr Deptuła,1,3 Ewelina Piktel,1 Mateusz Cieśluk,1 Agnieszka Z Wilczewska,4 Jan R Dąbrowski,3 Robert Bucki1 1Department of Microbiological and Nanobiomedical Engineering, Medical University of Białystok, 2Department of Intergrated Dentistry, Medical University of Białystok, 3Department of Materials and Biomedical Engineering, Białystok University of Technology, 4Institute of Chemistry, University of Białystok, Białystok, Poland Abstract: 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. Keywords: chlorhexidine, magnetic nanoparticles, antimicrobial properties, anti-biofilm

Katarzyna Niemirowicz,1 Ewelina Piktel,1 Agnieszka Z Wilczewska,2 Karolina H Markiewicz,2 Bonita Durnaś,3 Marzena Wątek,4 Irena Puszkarz,3 Marta Wróblewska,5,6 Wieslawa Niklińska,7 Paul B Savage,8 Robert Bucki1,3 1Department of Microbiological and Nanobiomedical Engineering, Medical University of Bialystok, 2Institute of Chemistry, University of Bialystok, Bialystok, 3Department of Physiology, Pathophysiology and Immunology of Infections, The Faculty of Health Sciences of the Jan Kochanowski University in Kielce, 4Holy Cross Oncology Center of Kielce, Kielce, 5Department of Dental Microbiology, Medical University of Warsaw, 6Department of Microbiology, Central Clinical Hospital in Warsaw, Warsaw, 7Department of Histology and Embryology, Medical University of Bialystok, Bialystok, Poland; 8Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA Abstract: 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. Keywords: synergistic activity, antibiotic-resistant bacteria, LL-37 peptide, ceragenins, magnetic nanoparticles

Katarzyna Niemirowicz,1 Izabela Prokop,2 Agnieszka Z Wilczewska,3 Urszula Wnorowska,1 Ewelina Piktel,1 Marzena Wątek,4 Paul B Savage,5 Robert Bucki1,6 1Department of Microbiological and Nanobiomedical Engineering, Medical University of Bialystok, 2Department of Medicinal Chemistry, Medical University of Bialystok, 3Institute of Chemistry, University of Bialystok, Bialystok, 4Department of Hematology, Holy Cross Oncology Center of Kielce, Kielce, Poland; 5Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA; 6Department of Physiology, Pathophysiology and Microbiology of Infections, The Faculty of Health Sciences of the Jan Kochanowski University in Kielce, Kielce, Poland Abstract: 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. Keywords: anticancer activity, colorectal cancer, ceragenin, cathelicidin LL-37, magnetic nanoparticles

Katarzyna Niemirowicz,1,2 Izabela Swiecicka,3 Agnieszka Z Wilczewska,4 Iwona Misztalewska,4 Beata Kalska-Szostko,4 Kamil Bienias,2 Robert Bucki,1,5,6 Halina Car21Department of Microbiological and Nanobiomedical Engineering, 2Department of Experimental Pharmacology, Medical University of Bialystok, 3Department of Microbiology, 4Institute of Chemistry, University of Bialystok, Bialystok, 5Faculty of Health Sciences, Jan Kochanowski University, Kielce, Poland; 6Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA, USAAbstract: Superparamagnetic iron oxide nanoparticles (SPIONs) and their derivatives (aminosilane and gold-coated) have been widely investigated in numerous medical applications, including their potential to act as antibacterial drug carriers that may penetrate into bacteria cells and biofilm mass. Pseudomonas aeruginosa is a frequent cause of infection in hospitalized patients, and significant numbers of currently isolated clinical strains are resistant to standard antibiotic therapy. Here we describe the impact of three types of SPIONs on the growth of P. aeruginosa during long-term bacterial culture. Their size, structure, and physicochemical properties were determined using transmission electron microscopy, X-ray diffraction analysis, and Fourier transform infrared spectroscopy. We observed significant inhibition of P. aeruginosa growth in bacterial cultures continued over 96 hours in the presence of gold-functionalized nanoparticles (Fe3O4@Au). At the 48-hour time point, growth of P. aeruginosa, as assessed by the number of colonies grown from treated samples, showed the highest inhibition (decreased by 40%). These data provide strong evidence that Fe3O4@Au can dramatically reduce growth of P. aeruginosa and provide a platform for further study of the antibacterial activity of this nanomaterial.Keywords: antibacterial activity, Pseudomonas aeruginosa, superparamagnetic nanoparticles, iron oxides, gold-coated nanoparticles