The Substantial Role of Cell and Nanoparticle Surface Properties in the Antibacterial Potential of Spherical Silver Nanoparticles [Response to Letter]

Marta Krychowiak-Maśnicka,1,* Weronika Paulina Wojciechowska,1,* Karolina Bogaj,1 Aleksandra Bielicka-Giełdoń,2 Ewa Czechowska,3 Magdalena Ziąbka,4 Magdalena Narajczyk,5 Anna Kawiak,6 Tomasz Mazur,7 Beata Szafranek,2 Aleksandra Królicka1 1University of Gdansk, Intercollegiate Faculty of Biotechnology, Laboratory of Biologically Active Compounds, Gdansk, Poland; 2University of Gdansk, Faculty of Chemistry, Gdansk, Poland; 3University of Gdansk, Intercollegiate Faculty of Biotechnology, Laboratory of Experimental and Translational Immunology, Gdansk, Poland; 4AGH University of Krakow, Faculty of Materials Science and Ceramics, Department of Ceramics and Refractories, Krakow, Poland; 5University of Gdansk, Faculty of Biology, Bioimaging Laboratory, Gdansk, Poland; 6University of Gdansk, Intercollegiate Faculty of Biotechnology, Laboratory of Plant Protection and Biotechnology, Gdansk, Poland; 7AGH University of Krakow, Academic Centre for Materials and Nanotechnology, Krakow, Poland*These authors contributed equally to this workCorrespondence: Marta Krychowiak-Maśnicka, Laboratory of Biologically Active Compounds, Intercollegiate Faculty of Biotechnology of the University of Gdansk and the Medical University of Gdansk, University of Gdansk, Abrahama 58, Gdansk, 80-307, Poland, Email [email protected]

The Substantial Role of Cell and Nanoparticle Surface Properties in the Antibacterial Potential of Spherical Silver Nanoparticles

Marta Krychowiak-Maśnicka,1,* Weronika Paulina Wojciechowska,1,* Karolina Bogaj,1 Aleksandra Bielicka-Giełdoń,2 Ewa Czechowska,3 Magdalena Ziąbka,4 Magdalena Narajczyk,5 Anna Kawiak,6 Tomasz Mazur,7 Beata Szafranek,2 Aleksandra Królicka1 1University of Gdansk, Intercollegiate Faculty of Biotechnology, Laboratory of Biologically Active Compounds, Gdansk, Poland; 2University of Gdansk, Faculty of Chemistry, Gdansk, Poland; 3University of Gdansk, Intercollegiate Faculty of Biotechnology, Laboratory of Experimental and Translational Immunology, Gdansk, Poland; 4AGH University of Krakow, Faculty of Materials Science and Ceramics, Department of Ceramics and Refractories, Krakow, Poland; 5University of Gdansk, Faculty of Biology, Bioimaging Laboratory, Gdansk, Poland; 6University of Gdansk, Intercollegiate Faculty of Biotechnology, Laboratory of Plant Protection and Biotechnology, Gdansk, Poland; 7AGH University of Krakow, Academic Centre for Materials and Nanotechnology, Krakow, Poland*These authors contributed equally to this workCorrespondence: Marta Krychowiak-Maśnicka, Laboratory of Biologically Active Compounds, Intercollegiate Faculty of Biotechnology of the University of Gdansk and the Medical University of Gdansk, University of Gdansk, Abrahama 58, Gdansk, 80-307, Poland, Email [email protected]: Although it is well known that the size, shape, and surface chemistry affect the biological potential of silver nanoparticles (AgNPs), the published studies that have considered the influence of AgNP surface on antibacterial activity have not provided conclusive results. This is the first study whose objective was to determine the significance of the surface net charge of AgNPs on their antibacterial potential, attraction to bacterial cells, and cell envelope disruption, considering differences in bacterial surface properties.Methods: We evaluated five commercial AgNP colloids with identical size and shape but different surface ligands. We thoroughly characterized their physicochemical properties, including the zeta potential, hydrodynamic diameter, and polydispersity index, and determined the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC), along with silver absorption into bacterial cells. Moreover, we investigated structural changes in bacteria treated with AgNPs by using a crystal violet assay and electron microscopy.Results: The zeta potential of AgNPs ranged from − 47.6 to +68.5 mV, with a hydrodynamic diameter of 29– 87 nm and a polydispersity index of 0.349– 0.863. Bacterial susceptibility varied significantly (0.5 ≤ MIC ≤ 256 μg Ag/mL; 1 ≤ MBC ≤ 256 μg Ag/mL); we found the lowest susceptibility in bacteria with a cell wall or a polysaccharide capsule. The most active AgNPs (0.5 ≤ MIC ≤ 32 μg Ag/mL; 2 ≤ MBC ≤ 64 μg Ag/mL) had a moderate surface charge (− 21.5 and +14.9 mV). The antibacterial potential was unrelated to ion dissolution or cell envelope disruption, and bacterial cells absorbed less of the most active AgNPs (1.75– 7.65%).Conclusion: Contrary to previous reports, we found that a moderate surface charge is crucial for the antibacterial activity of AgNPs, and that a significant attraction of the nanoparticle to the cell surface reduces the antibacterial potential of AgNPs. These findings challenge the existing views on AgNP antibacterial mechanisms and interactions with bacterial cells. Keywords: human pathogen, ESKAPE, Klebsiella pneumoniae, cell envelope, ICP-OES, cell–nanoparticle interactio

Effects of flavonoids on glycosaminoglycan synthesis: implications for substrate reduction therapy in Sanfilippo disease and other mucopolysaccharidoses

Sanfilippo disease (mucopolysaccharidosis type III, MPS III) is a severe metabolic disorder caused by accumulation of heparan sulfate (HS), one of glycosaminoglycans (GAGs), due to a genetic defect resulting in a deficiency of GAG hydrolysis. This disorder is characterized as the most severe neurological form of MPS, revealing rapid deterioration of brain functions. Among therapeutic approaches for MPS III, one of the most promising appears to be the substrate reduction therapy (SRT). Genistein (5, 7-dihydroxy-3- (4-hydroxyphenyl)-4H-1-benzopyran-4-one) is an isoflavone that has been used in SRT for MPS III. In this report, we tested effects of other flavonoids (apigenin, daidzein, kaempferol and naringenin) on GAG synthesis. Their cytotoxicity and anti-proliferation features were also tested. We found that daidzein and kaempferol inhibited GAG synthesis significantly. Moreover, these compounds were able to reduce lysosomal storage in MPS IIIA fibroblasts. Interestingly, although genistein is believed to inhibit GAG synthesis by blocking the tyrosine kinase activity of the epidermal growth factor receptor, we found that effects of other flavonoids were not due to this mechanism. In fact, combinations of various flavonoids resulted in significantly more effective inhibition of GAG synthesis than the use of any of these compounds alone. These results, together with results published recently by others, suggest that combination of flavonoids can be considered as a method for improvement of efficiency of SRT for MPS III

Floral micromorphology, histochemistry, ultrastructure and chemical composition of floral secretions in three Neotropical <i>Maxillariella</i> species (Orchidaceae)

Abstract Floral morphological adaptations and composition of secretions aim to ensure reproductive success. Maxillariella is part of the largest subtribe of Orchidaceae, and Maxillariella spp. are important components of the orchid flora of the Neotropics. The aim of this paper was to provide a detailed study of the reproductive biology of three morphologically and geographically distinct species: M. sanguinea, M. variabilis and M. vulcanica. For many years, species in this group were considered rewardless, but several studies have revealed that lips of some species may secrete resins. However, most published research has mainly focused on investigating either micromorphology (SEM, TEM, histochemistry) or fragrance composition (GC–MS). In this study, we make the first attempt to investigate Maxillariella flowers in a more comparative manner by combining both aspects. In all investigated species we reported the presence of resins with lipids, sugars and/or proteins, suggesting a potential role as a food reward. Scant quantities of residues indicate that they are produced periodically in small quantities. Chemical analysis revealed significant differences between species, however, the presence of some compounds was constant. Cycloartenal and cycloartenol (main ingredients of resin and wax-like material in some Maxillariinae) were not been found.</jats:p

Synthesis of antimicrobial silver nanoparticles through a photomediated reaction in an aqueous environment

Rafał Banasiuk,1,* Joanna E Frackowiak,2,* Marta Krychowiak,1 Marta Matuszewska,1 Anna Kawiak,1 Magdalena Ziabka,3 Zofia Lendzion-Bielun,4 Magdalena Narajczyk,5 Aleksandra Krolicka1 1Department of Biotechnology, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, 2Department of Pathophysiology, Medical University of Gdansk, Gdansk, 3Faculty of Materials Science and Ceramics, Department of Ceramics and Refractories, AGH-University of Science and Technology, Krak&oacute;w, 4Institute of Chemical and Environment Engineering, West Pomeranian University of Technology, Szczecin, 5Faculty of Biology, Laboratory of Electron Microscopy, University of Gdansk, Gdansk, Poland *These authors contributed equally to&nbsp;this work Abstract: A fast, economical, and reproducible method for nanoparticle synthesis has been developed in our laboratory. The reaction is performed in an aqueous environment and utilizes light emitted by commercially available 1 W light-emitting diodes (&lambda; =420 nm) as the catalyst. This method does not require nanoparticle seeds or toxic chemicals. The irradiation process is carried out for a period of up to 10 minutes, significantly reducing the time required for synthesis as well as environmental impact. By modulating various reaction parameters silver nanoparticles were obtained, which were predominantly either spherical or cubic. The produced nanoparticles demonstrated strong antimicrobial activity toward the examined bacterial strains. Additionally, testing the effect of silver nanoparticles on the human keratinocyte cell line and human peripheral blood mononuclear cells revealed that their cytotoxicity may be limited by modulating the employed concentrations of nanoparticles. Keywords: antimicrobial activity, green synthesis, nanocubes, nanospheres&nbsp

Silver Nanoparticles as Chlorhexidine and Metronidazole Drug Delivery Platforms: Their Potential Use in Treating Periodontitis [Corrigendum]

Steckiewicz KP, Cieci&#x00F3;rski P, Barci&#x0144;ska E, et al. Int J Nanomedicine. 2022;17:495&#x2013;517. Our authors have advised that the funding source number listed in the Acknowledgment section on page 513 was incorrect. The sentence should read from &#x201C;This work was supported by PRELUDIUM grant 2017/27/N/NZ7/0267 from the Polish National Science Centre&#x2026;&#x201D; to &#x201C;This work was supported by PRELUDIUM grant 2017/27/N/NZ7/02675 from the Polish National Science Centre&#x2026;&#x201D; The authors apologize for this oversight

Salicylic acid can reduce infection symptoms caused by Dickeya solani in tissue culture grown potato (Solanum tuberosum L.) plants

The potential for control of Dickeya solani infections in potato by elicitation of in vitro grown potato plants with salicylic acid (SA) was investigated by selective plating and confocal laser scanning macroscopy (CLSM). In replicated experiments potato plants grown on medium supplemented with 25 or 50 μM of SA were evaluated for the phytotoxic effects. Potato plants grown on medium supplemented with SA and inoculated with GFP-tagged D. solani were investigated for blackleg development and colonization of potato plants by the bacteria. Three days after inoculation, colonization of roots by D. solani was observed in 100 % control plants grown on medium without SA but not in plants grown on medium supplemented with 50 μM SA. After 14 days, 100 % of control plants showed severe disease symptoms, whereas plants grown on medium supplemented with 50 μM SA and inoculated with bacteria did not express any symptoms. After 14 days bacteria were found inside 100 % stems of control plants in densities of ca. 103–104 cfu g−1 and inside ca. 10–15 % stems of plants treated with 50 μM SA in densities similar to these in the control plants. The GFP-tagged bacteria were macroscopically detected on the surface of the roots of control plants but not on the surface of the plants treated with 50 μM SA 14 days after inoculation. The implications of SA treatments on plant fitness and disease development are discussed.</p

Genistein in Sanfilippo disease: A randomized controlled crossover trial

Objective: Sanfilippo disease (mucopolysaccharidosis type III [MPS III]) is a rare neurodegenerative metabolic disease caused by a deficiency of 1 of the 4 enzymes involved in the degradation of heparan sulfate (HS), a glycosaminoglycan (GAG). Genistein has been proposed as potential therapy but its efficacy remains uncertain. We aimed to determine the efficacy of genistein in MPS III. Methods: Thirty patients were enrolled. Effects of genistein were determined in a randomized, crossover, placebocontrolled intervention with a genistein-rich soy isoflavone extract (10mg/kg/day of genistein) followed by an openlabel extension study for patients who were on genistein during the last part of the crossover. Results: Genistein resulted in a significant decrease in urinary excretion of total GAGs (p 0.02, slope = 0.68mg GAGs/mmol creatinine/mo) and in plasma concentrations of HS (p 0.01, slope = 15.85ng HS/ml/mo). No effects on total behavior scores or on hair morphology were observed. Parents or caregivers could not predict correctly during which period of the crossover a patient was on genistein. Interpretation: Genistein at 10mg/kg/day effectively reduces urinary excretion of GAGs and plasma HS concentration in patients with MPS III. However, the absolute reduction in GAGs and in HS is small and values after 12 months of treatment remain within the range as observed in untreated patients. No clinical efficacy was detected. Substantially higher doses of genistein might be more effective as suggested by recent studies in animal models. ANN NEUROL 2012; 71: 110-12