Luminescent gold nanoclusters for bioimaging applications

• Nonappa

Beilstein J. Nanotechnol. 2020, 11, 533–546, doi:10.3762/bjnano.11.42

• interact with S. aureus, DVFLGRGGGC (Pep10) and RHPDYSVVLLLRGGGC (Pep16), containing the sequences no. 348 to 352 and no. 361 to 372, were synthesized and used for the synthesis of Au-Pep10 and Au-pep16 NCs. Interestingly, both Au-pep10 and Au-pep16 NCs yielded similar results suggesting that these

• representation of Au-MTU/Prot NC synthesis. D) Microscopy images of S. aureus after treatment with Au-MTU/Prot NCs, Au-MTU/Prot NCs, and control. The red channel was excited at 405 nm. The images were 40 μm × 40 μm. E) A cross-sectional schematic view of a bacterium treated with Au-MTU/Prot. Figure panel 2A is

Facile biogenic fabrication of hydroxyapatite nanorods using cuttlefish bone and their bactericidal and biocompatibility study

• Satheeshkumar Balu,
• Manisha Vidyavathy Sundaradoss,
• Swetha Andra and
• Jaison Jeevanandam

Beilstein J. Nanotechnol. 2020, 11, 285–295, doi:10.3762/bjnano.11.21

• the TGA data revealed the thermal stability of Hap NRs. In addition, the antibacterial study showed a significant inhibitory effect of CB-Hap NRs against S. aureus (zone of inhibition – 14.5 ± 0.5 mm) and E. coli (13 ± 0.5 mm), whereas the blood compatibility test showed that the CB-Hap NRs exhibited

• can be noted from the literature that nanometer-sized Hap can effectively inhibit antibacterial activity but only when doped or cationic-substituted [55][56]. In contrast, the CB-derived Hap nanorods in the present study show optimum bactericidal effect on E. coli and S. aureus due to the size (>50 nm

• ) and morphology of the material. However, no such activity was observed for CB alone. The obtained results are displayed in Figure 6 and the zone of inhibition in Table 1 shows a better bactericidal effect of Hap NRs towards S. aureus as compared with E. coli. This is due to the variations in cell

Novel hollow titanium dioxide nanospheres with antimicrobial activity against resistant bacteria

• Carol López de Dicastillo,
• Cristian Patiño,
• María José Galotto,
• Yesseny Vásquez-Martínez,
• Claudia Torrent,
• Daniela Alburquenque,
• Alejandro Pereira and
• Juan Escrig

Beilstein J. Nanotechnol. 2019, 10, 1716–1725, doi:10.3762/bjnano.10.167

• bacteria, including resistant E. coli and S. aureus strains, and when compared to commercial TiO2 nanoparticles, CSTiO2 nanospheres exhibited superior performance. In addition, the positive effect of UV irradiation on the antimicrobial activity was demonstrated. Keywords: antimicrobial nanoparticles

• 622-4) and Escherichia coli (control strain ATCC®25922TM and resistant strain E. coli 33.1). When the analysis was done using control strains, the results in Table 1 indicate that CSTiO2 presented an improved antibacterial activity against S. aureus and a similar activity against E. coli in comparison

• bacteria, such as control and resistant E. coli strains, than Gram-positive bacteria, such as S. aureus ATCC 6538, MRSA 97-7 and MRSA 622-4. Different mechanisms of antimicrobial activity can be exerted by NPs. Specifically, in the case of TiO2 NPs, previous works have declared bactericidal activity via

Preparation of alginate–chitosan–cyclodextrin micro- and nanoparticles loaded with anti-tuberculosis compounds

• Albert Ivancic,
• Fliur Macaev,
• Fatma Aksakal,
• Veaceslav Boldescu,
• Serghei Pogrebnoi and
• Gheorghe Duca

Beilstein J. Nanotechnol. 2016, 7, 1208–1218, doi:10.3762/bjnano.7.112

• addition to this, ISN has an antibacterial effect against gram-positive bacteria (B. cereus, C. tuberculostearicum, S. aureus MR, S. haemolyticus, S. hominis, and S. salivarius) confirmed by numerous reports on its antibacterial activity [21][22][23][24][25]. The antibacterial activity of ISN has been

Ultrastructural changes in methicillin-resistant Staphylococcus aureus induced by positively charged silver nanoparticles

• Dulce G. Romero-Urbina,
• Humberto H. Lara,
• J. Jesús Velázquez-Salazar,
• M. Josefina Arellano-Jiménez,
• Eduardo Larios,
• Anand Srinivasan,
• Jose L. Lopez-Ribot and
• Miguel José Yacamán

Beilstein J. Nanotechnol. 2015, 6, 2396–2405, doi:10.3762/bjnano.6.246

• ; Staphylococcus aureus; wall teichoic acids; Introduction Bacterial infections are a major reason of morbidity and mortality globally [1], and most infections can be attributed to species of the genus Staphylococcus [2]. Staphylococcus aureus (S. aureus) is well known for its ability to acquire genetic

• resistance against almost all antibiotics [3]. As penicillin and other β-lactams were previously very efficient antibiotics in treating staphylococcal infections, the prevalent resistance of methicillin-resistant Staphylococcus aureus (MRSA) has made therapy continuously more complex [4]. S. aureus has also

• pressure. MRSA is resistant to all ß-lactam antibiotics due to its production of an extra penicillin-binding protein (PBP2a) [8]. With scarce management options for MRSA, there is a pressing necessity for the development of novel bactericides [9]. S. aureus is capable of causing chronic bone and joint

Synthesis, characterization and in vitro effects of 7 nm alloyed silver–gold nanoparticles

• Simon Ristig,
• Svitlana Chernousova,
• Wolfgang Meyer-Zaika and
• Matthias Epple

Beilstein J. Nanotechnol. 2015, 6, 1212–1220, doi:10.3762/bjnano.6.124

• complexes and spermatozoa, the nanoparticles showed toxic effects when the molar silver content was higher than 50%. Still, the effect was lower than the expected toxicity based on the silver content [38]. Similar results were found for human gingival fibroblasts and S. aureus [25]. For our investigations

Fulleropeptide esters as potential self-assembled antioxidants

• Mira S. Bjelaković,
• Tatjana J. Kop,
• Jelena Đorđević and
• Dragana R. Milić

Beilstein J. Nanotechnol. 2015, 6, 1065–1071, doi:10.3762/bjnano.6.107

• wide range of activities of fullerene–peptide conjugates has been studied [3][7][16]. Fulleropeptides synthesized by Prato's research group [17] showed a good bacteriostatic activity against Gram-positive bacterium S. aureus making it interesting for potential antimicrobial chemotherapeutics. Recently

Hydrophobic interaction governs unspecific adhesion of staphylococci: a single cell force spectroscopy study

• Nicolas Thewes,
• Peter Loskill,
• Philipp Jung,
• Henrik Peisker,
• Markus Bischoff,
• Mathias Herrmann and
• Karin Jacobs

Beilstein J. Nanotechnol. 2014, 5, 1501–1512, doi:10.3762/bjnano.5.163

• catalase and superoxide dismutase [3]. Only recently, the genome of S. carnosus strain TM300 has been decoded [4][5]. In contrast to pathogenic staphylococcal species, such as S. aureus and S. epidermidis, the genome of S. carnosus lacks significant amounts of mobile genetic elements, and is poor in

• repetitive DNA sequences that are thought to facilitate the plasticity of genomes by allowing for enhanced genomic diversification due to recombinational events [5]. Although the S. carnosus genome encodes some homologues of adhesion factors found in S. aureus, it lacks the majority of adhesive molecules of

• other hydrophobic macromolecules may contribute to adhesion. For S. aureus for example, teichoic acids are reported to be strongly hydrophilic [40]. Our model of bacterial adhesion, which will be proposed in the following, however, is not depending on the exact type of adhesive mediator. Figure 8A

Antimicrobial nanospheres thin coatings prepared by advanced pulsed laser technique

• Alina Maria Holban,
• Valentina Grumezescu,
• Alexandru Mihai Grumezescu,
• Bogdan Ştefan Vasile,
• Roxana Truşcă,
• Rodica Cristescu,
• Gabriel Socol and
• Florin Iordache

Beilstein J. Nanotechnol. 2014, 5, 872–880, doi:10.3762/bjnano.5.99

• -CS-Fe3O4@EUG nanospheres diameter sizes range between 20 and 80 nm. These MAPLE-deposited coatings acted as bioactive nanosystems and exhibited a great antimicrobial effect by impairing the adherence and biofilm formation of Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa

• nanoparticles; nanospheres; P. aeruginosa; polylactic acid; S. aureus; Introduction Driven by more and more microbial antibiotic resistance, alternative therapeutic approaches are emerging [1][2][3][4]. Polar and nonpolar, functionalized and non-functionalized magnetite nanostructures have proven successfully

• biocompatibility with human cells, the newly synthesized nano-active thin coating exhibited a great antimicrobial activity. The surface inhibited both S. aureus and P. aeruginosa attachment and also the formation of non-specific biofilms. MAPLE deposited thin films interfere with biofilm formation both in the

Antimicrobial properties of CuO nanorods and multi-armed nanoparticles against B. anthracis vegetative cells and endospores

• Pratibha Pandey,
• Merwyn S. Packiyaraj,
• Himangini Nigam,
• Gauri S. Agarwal,
• Beer Singh and
• Manoj K. Patra

Beilstein J. Nanotechnol. 2014, 5, 789–800, doi:10.3762/bjnano.5.91

• , generated on copper foil as effective antibacterial against E. coli bacteria when the bacterial suspension drop was tested on these surfaces. Perelshtein et al. [19] have reported antibacterial CuO-cotton textile against E. coli and S. aureus. Gao et al. [20] reported strong antibacterial activity of CuO

Atomic force microscopy recognition of protein A on Staphylococcus aureus cell surfaces by labelling with IgG–Au conjugates

• Elena B. Tatlybaeva,
• Hike N. Nikiyan,
• Alexey S. Vasilchenko and
• Dmitri G. Deryabin

Beilstein J. Nanotechnol. 2013, 4, 743–749, doi:10.3762/bjnano.4.84

• cell-surface markers for atomic force microscopy (AFM). The use of 30-nm size Au nanoparticles conjugated with immunoglobulin G (IgG) allowed the visualization, localization and distribution of protein A–IgG complexes on the surface of S. aureus. The selectivity of the labelling method was confirmed in

• mixtures of S. aureus with Bacillus licheniformis cells, which differed by size and shape and had no IgG receptors on the surface. A preferential binding of the IgG–Au conjugates to S. aureus was obtained. Thus, this novel approach allows the identification of protein A and other IgG receptor-bearing

• aggregation of conjugates as indicated in [13]. These results were used as background for the following labelling and recognition of IgG–Au conjugates on the bacterial surfaces. As visualized in the second step of the study, intact S. aureus cells appeared on the mica surface as grape-like clusters of round

Photocatalytic antibacterial performance of TiO₂ and Ag-doped TiO₂ against S. aureus. P. aeruginosa and E. coli

• Kiran Gupta,
• R. P. Singh,
• Ashutosh Pandey and
• Anjana Pandey

Beilstein J. Nanotechnol. 2013, 4, 345–351, doi:10.3762/bjnano.4.40

• investigated against Gram-positive Staphylococcus aureus (S. aureus), and Gram-negative Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli) bacteria under visible light. Results and Discussion XRD of TiO2 and Ag-doped TiO2 The samples were annealed at 450 °C to achieve crystallization in TiO2

• both concentrations (3% and 7%) were toxic to all the bacteria tested. However, application of 7% doped Ag–TiO2 nanoparticles killed 100% P. aeruginosa cells at 40 mg/30 mL concentration, while 5% and 4% viabilities of S. aureus and E. coli were obtained, respectively. It is also clear from Figure 6

• nanoparticles at 60 mg/30 mL of culture, 0% viability in the case of P. aeruginosa was recorded, while in the case of S. aureus and E. coli 7% and 3% viabilities were recorded. Therefore 7% doped silver nanoparticles at 60 mg/30 mL of bacterial culture (0.2 O.D. at 660 nm) is the optimum concentration for the

Paper modified with ZnO nanorods – antimicrobial studies

• Mayuree Jaisai,
• Sunandan Baruah and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2012, 3, 684–691, doi:10.3762/bjnano.3.78

• in cellular internalization of ZnO nanoparticles has also been observed by Appierot et al. [6] in a study of their antibacterial effect on E. coli and S. aureus. This work reports on an antimicrobial paper containing zinc oxide (ZnO) nanorods grown by a hydrothermal process, and which can be used for

• environment leading to the rupture of the bacterial cell wall [23]. S. aureus, being a Gram-positive bacterium, has a thicker cell wall [24], and consequently its immobilization by using the ZnO-coated antimicrobial paper is comparatively lower than that of E. coli. The highest antimicrobial activity was

• , 48 and 72 h with maximum inhibition of 2.8 cm after 72 h under halogen-light illumination. For S. aureus, the maximum zone of inhibition noted was 2.1 cm for 72 h incubation under 1 klx halogen light. The minimum zones of inhibition were noted for dark conditions confirming the enhancement of the

Magnetic nanoparticles for biomedical NMR-based diagnostics

• Huilin Shao,
• Tae-Jong Yoon,
• Monty Liong,
• Ralph Weissleder and
• Hakho Lee

Beilstein J. Nanotechnol. 2010, 1, 142–154, doi:10.3762/bjnano.1.17

• targets. For example, detection of the bacterium Staphylococcus aureus was recently reported with the μNMR device. S. aureus were initially incubated with MNPs derivatized with vancomycin, a drug which binds to D-alanyl–D-alanine moieties in the bacterial cell wall to form dense clusters (Figure 6a) [14

• T2 relaxation time. (Reproduced with permission from [13][14]. Copyright 2002, 2008 Nature Publishing Group.) DMR detection of bacteria by tagging the bacterial samples with MNPs. (a) Scanning electron micrograph of S. aureus. Inset shows TEM of S. aureus targeted by CLIO conjugated with vancomycin

• . MNPs formed dense clusters on the bacterial wall. Elemental analysis by energy dispersive X-ray spectrometry further confirmed the binding of nanoparticles to the bacteria. (b) Changes to T2 with varying number of S. aureus. The DMR system had a detection sensitivity of a few colony-forming units (CFUs