Biomedical Applications: Gram‐Negative Bacteria Targeting Mediated by Carbohydrate–Carbohydrate Interactions Induced by Surface‐Modified Nanoparticles (Adv. Funct. Mater. 48/2019)

2019 ◽  
Vol 29 (48) ◽  
pp. 1970325 ◽  
Author(s):  
Larissa Brentano Capeletti ◽  
Jessica Fernanda Affonso Oliveira ◽  
Lívia Mesquita Dias Loiola ◽  
Flávia Elisa Galdino ◽  
Denys Ewerton Silva Santos ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Surface Modified ◽  
Surface Modified Nanoparticles

Gram‐Negative Bacteria Targeting Mediated by Carbohydrate–Carbohydrate Interactions Induced by Surface‐Modified Nanoparticles

2019 ◽  
Vol 29 (48) ◽  
pp. 1904216 ◽  
Author(s):  
Larissa Brentano Capeletti ◽  
Jessica Fernanda Affonso Oliveira ◽  
Lívia Mesquita Dias Loiola ◽  
Flávia Elisa Galdino ◽  
Denys Ewerton Silva Santos ◽  
...  
Keyword(s):  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Surface Modified ◽  
Surface Modified Nanoparticles

scholarly journals Polyethylene Glycol6000/carbon Nanodots as Fluorescent Bioimaging Agents

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 677 ◽  
Author(s):  
Chun-Chieh Fu ◽  
Chun-Yung Wu ◽  
Chih-Ching Chien ◽  
Tai-Hao Hsu ◽  
Shih-Fu Ou ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Carbon Quantum Dots ◽  
Carbon Nanodots ◽  
Gram Negative Bacteria ◽  
Fluorescent Properties ◽  
Gram Positive ◽  
Gram Negative ◽  
Different Types ◽  
Living Organisms ◽  
Surface Modified

Photoluminescent nanomaterials have immense potential for use in biological systems due to their excellent fluorescent properties and small size. Traditional semiconductor quantum dots are heavy-metal-based and can be highly toxic to living organisms, besides their poor photostability and low biocompatibility. Nano-sized carbon quantum dots and their surface-modified counterparts have shown improved characteristics for imaging purposes. We used 1,3, 6-trinitropyrene (TNP) and polyethylene glycol6000 (PEG6000) in a hydrothermal method to prepare functional polyethylene glycol6000/carbon nanodots (PEG6000/CDs) and analyzed their potential in fluorescent staining of different types of bacteria. Our results demonstrated that PEG6000/CDs stained the cell pole and septa of gram-positive bacteria B. Subtilis and B. thuringiensis but not those of gram-negative bacteria. The optimal concentration of these composite nanodots was approximately 100 ppm and exposure times varied across different bacteria. The PEG6000/CD composite had better photostability and higher resistance to photobleaching than the commercially available FM4-64. They could emit two wavelengths (red and green) when exposed to two different wavelengths. Therefore, they may be applicable as bioimaging molecules. They can also be used for differentiating different types of bacteria owing to their ability to differentially stain gram-positive and gram-negative bacteria.

scholarly journals Removal of Endotoxin during Purification of Poly(3-Hydroxybutyrate) from Gram-Negative Bacteria

1999 ◽  
Vol 65 (6) ◽  
pp. 2762-2764 ◽  
Author(s):  
Sang Yup Lee ◽  
Jong-il Choi ◽  
Kyuboem Han ◽  
Ji Yong Song
Keyword(s):  
Biomedical Applications ◽  
Ralstonia Eutropha ◽  
Gram Negative Bacteria ◽  
Endotoxin Level ◽  
Bacterial Strains ◽  
Digestion Time ◽  
Digestion Method ◽  
Gram Negative ◽  
E Coli ◽  
Chloroform Extraction

ABSTRACT Poly(3-hydroxybutyrate) (PHB) was produced by cultivating several gram-negative bacteria, including Ralstonia eutropha,Alcaligenes latus, and recombinant Escherichia coli. PHB was recovered from these bacteria by two different methods, and the endotoxin levels were determined. When PHB was recovered by the chloroform extraction method, the endotoxin level was less than 10 endotoxin units (EU) per g of PHB irrespective of the bacterial strains employed and the PHB content in the cell. The NaOH digestion method, which was particularly effective for the recovery of PHB from recombinant E. coli, was also examined for endotoxin removal. The endotoxin level present in PHB recovered by 0.2 N NaOH digestion for 1 h at 30°C was higher than 104EU/g of PHB. Increasing the digestion time or NaOH concentration reduced the endotoxin level to less than 1 EU/g of PHB. It was concluded that PHB with a low endotoxin level, which can be used for various biomedical applications, could be produced by chloroform extraction. Furthermore, PHB with a much lower endotoxin level could be produced from recombinant E. coli by simple NaOH digestion.

Facile and Novel Synthesis of Spiky Gold Nanoparticles as an Efficient Antimicrobial Agent against Pseudomonas Aeruginosa

2021 ◽  
Vol 24 ◽  
Author(s):  
Farooq Aziz ◽  
Muhammad Rashid ◽  
Mubashar Rehman ◽  
Muhammad Rafique ◽  
Muhammad Imran
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Gold Nanoparticles ◽  
Biomedical Applications ◽  
Antibacterial Agents ◽  
Reduction Method ◽  
Surface Plasmon Resonance Peak ◽  
Gram Negative Bacteria ◽  
Plasmon Resonance Peak ◽  
Gram Negative ◽  
Novel Synthesis

Aims: The study aims to develop advanced antibacterial agents as nanoparticles instead of antibiotics due to the emergence of antimicrobial resistance. Background: Pseudomonas aeruginosa is capable of causing many diseases, including severe bacterial pneumonia. There is a need for an efficient antibacterial agent to kill these pathogens. Objective: The objective of the study is to synthesize advanced antibacterial agents as nanoparticles for biomedical applications that can play a vital role in killing Gram-negative bacteria (Pseudomonas aeruginosa). Method: A novel fabricated growth of hydrophilic spiky gold nanoparticles (SGNPs) via reduction method is reported. Results: The surface plasmon resonance peak of the synthesized SGNPs was tuned under the near-infrared range. The SGNPs have anisotropic and spiky morphology with 68 nm size and -58 mV surface charge. They are pure, possessing adsorption similar to the organic material. Pseudomonas aeruginosa treated with synthesized SGNPs showed 60% bacterial death at the concentration of 100 μM. Conclusion: This work consists of the novel synthesis of SGNPs via a safe and simple reduction method. The synthesized SGNPs exhibit strong antibacterial activity against the Gram-negative bacteria Pseudomonas aeruginosa measured using a microplate assay test. The result showed that these SGNPs are ideal for biomedical applications.

scholarly journals Synergistic Effects of Anionic/Cationic Dendrimers and Levofloxacin on Antibacterial Activities

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2894 ◽  
Author(s):  
Natalia Wrońska ◽  
Jean Pierre Majoral ◽  
Dietmar Appelhans ◽  
Maria Bryszewska ◽  
Katarzyna Lisowska
Keyword(s):  
Antibacterial Activity ◽  
Biomedical Applications ◽  
Synergistic Effects ◽  
Antibacterial Activities ◽  
Drug Dosage ◽  
General Interest ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Fluoroquinolone Antibiotics ◽  
Proteus Hauseri

Despite the numerous studies on dendrimers for biomedical applications, the antibacterial activity of anionic phosphorus dendrimers has not been explored. In our research, we evaluated the antibacterial activity of modified polycationic and polyanionic dendrimers in combination with levofloxacin (LVFX) against Gram-negative (Escherichia coli ATCC 25922, Proteus hauseri ATCC 15442) and Gram-positive (Staphylococcus aureus ATCC 6538) bacteria. In the case of Gram-negative bacteria, we concluded that a combination of dendrimers and antibiotic gave satisfactory results due to a synergistic effect. The use of fluoroquinolone antibiotics, such as LVFX, not only caused resistance in disease-causing microorganisms but also increased environmental pollution. Therefore, reduction of drug dosage is of general interest.

Production of nearly monodisperse Fe3O4 and Fe@Fe3O4 nanoparticles in aqueous medium and their surface modification for biomedical applications

2017 ◽  
Vol 31 (04) ◽  
pp. 1750014 ◽  
Author(s):  
Tirusew Tegafaw ◽  
Wenlong Xu ◽  
Sang Hyup Lee ◽  
Kwon Seok Chae ◽  
Yongmin Chang ◽  
...  
Keyword(s):  
Aqueous Medium ◽  
Photoelectron Spectroscopy ◽  
Quantum Interference ◽  
Biomedical Applications ◽  
Ir Absorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Surface Modified ◽  
Surface Modified Nanoparticles

Iron (Fe)-based nanoparticles are extremely valuable in biomedical applications owing to their low toxicity and high magnetization values at room temperature. In this study, we synthesized nearly monodisperse iron oxide (Fe3O4) and Fe@Fe3O4 (core: Fe, shell: Fe3O[Formula: see text] nanoparticles in aqueous medium under argon flow and then, coated them with various biocompatible ligands and silica. In this study, eight types of surface-modified nanoparticles were investigated, namely, Fe3O4@PAA (PAA = polyacrylic acid; [Formula: see text] of PAA = 5100 amu and 15,000 amu), Fe3O4@PAA–FA (FA = folic acid; [Formula: see text] of PAA = 5100 amu and 15,000 amu), Fe3O4@PEI–fluorescein (PEI = polyethylenimine; [Formula: see text] of PEI = 1300 amu), Fe@Fe3O4@PEI ([Formula: see text] of PEI = 10,000 amu), Fe3O4@SiO2 and Fe@Fe3O4@SiO2 nanoparticles. We characterized the prepared surface-modified nanoparticles using high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) absorption spectroscopy, a superconducting quantum interference device (SQUID), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) spectroscopy and confocal microscopy. Finally, we measured the cytotoxicity of the samples. The results indicate that the surface-modified nanoparticles are biocompatible and are potential candidates for various biomedical applications.

scholarly journals Antimicrobial Activity of Isoniazid in Conjugation with Surface-Modified Magnetic Nanoparticles against Mycobacterium tuberculosis and Nonmycobacterial Microorganisms

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Sarah Zargarnezhad ◽  
Ahmad Gholami ◽  
Mehdi Khoshneviszadeh ◽  
Seyedeh Narjes Abootalebi ◽  
Younes Ghasemi
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Magnetic Nanoparticles ◽  
Antibacterial Activities ◽  
Activation Process ◽  
Lipoamino Acid ◽  
Gram Negative ◽  
Modified Magnetic Nanoparticles ◽  
Surface Modified ◽  
Surface Modified Nanoparticles ◽  
Microdilution Broth

Isoniazid, the choice antitubercular agent, has only been employed against Mycobacterium tuberculosis. This study evaluated if the enzyme-mimetic activities of magnetic nanoparticles could accelerate the activation process of isoniazid against mycobacterial and, more importantly, non-mycobacterial microorganisms. First, magnetic nanoparticles were synthesized and coated by lipoamino acid; then, isoniazid was conjugated to synthesized nanoparticles. Antibacterial activities of nanoconjugated isoniazid were evaluated against Mycobacterium tuberculosis and four Gram-positive and Gram-negative nonmycobacterial strains through a microdilution broth process. Results showed that the required amount of isoniazid against Mycobacterium tuberculosis would decrease to 44.8% and 16.7% in conjugation with naked and surface-modified magnetic nanoparticles, respectively. Also, 32 μg/mL and 38 μg/mL of isoniazid in conjugation with naked and surface-modified nanoparticles, respectively, could prevent the growth of Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. Hence, the vicinity of magnetic nanoparticles with isoniazid could declare promising aspects of isoniazid antibacterial capabilities.

Functionalized Antimicrobial Electrospun Poly (vinyl alcohol) Nanowebs

2016 ◽  
Vol 11 (2) ◽  
pp. 155892501601100 ◽  
Author(s):  
Uday Turaga ◽  
Vinitkumar Singh ◽  
Anna Gibson ◽  
Shahrima Maharubin ◽  
Carol Korzeniewski ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Vinyl Alcohol ◽  
Biomedical Applications ◽  
Antimicrobial Properties ◽  
Poly Vinyl Alcohol ◽  
Biocompatible Polymers ◽  
Gram Negative Bacteria ◽  
Gram Negative

Electrospun poly (vinyl alcohol) [PVA] nanowebs functionalized with a commercially available microbiocidal solution Reputex™ 20 were prepared. The active ingredient of Reputex™ 20 is polyhexamethylene biguanides, a safe antiseptic. Fourier Transform Infrared spectroscopy confirmed the functionalization of PVA nanowebs. Functionalized nanowebs were characterized by evaluating their antimicrobial properties, breathability characteristics and tensile properties. Functionalized nanowebs demonstrated significant antimicrobial activity against both Gram positive and Gram negative bacteria. Nanowebs developed from biocompatible polymers like PVA, and functionalized with safe antiseptics, could find many biomedical applications such as wound bandages.

Bacterial-Mucosal Cell Junctional Complexes

1974 ◽  
Vol 32 ◽  
pp. 144-145
Author(s):  
Roger C. Wagner
Keyword(s):  
Intestinal Wall ◽  
Rat Colon ◽  
Mucosal Cell ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Mucosal Cells ◽  
Mucosal Lining ◽  
Degenerative Alterations ◽  
Junctional Complexes ◽  
Intestinal Mucosal Cells

Bacteria exhibit the ability to adhere to the apical surfaces of intestinal mucosal cells. These attachments either precede invasion of the intestinal wall by the bacteria with accompanying inflammation and degeneration of the mucosa or represent permanent anchoring sites where the bacteria never totally penetrate the mucosal cells.Endemic gram negative bacteria were found attached to the surface of mucosal cells lining the walls of crypts in the rat colon. The bacteria did not intrude deeper than 0.5 urn into the mucosal cells and no degenerative alterations were detectable in the mucosal lining.

Rapid demonstration of septic or infectious arthritis due to Gram-negative bacteria

1992 ◽  
Vol 50 (1) ◽  
pp. 686-687
Author(s):  
Jacob S. Hanker ◽  
Paul R. Gross ◽  
Beverly L. Giammara
Keyword(s):  
Chronic Arthritis ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Infectious Arthritis ◽  
Bacterial Arthritis ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Blood cultures are positive in approximately only 50 per cent of the patients with nongonococcal bacterial infectious arthritis and about 20 per cent of those with gonococcal arthritis. But the concept that gram-negative bacteria could be involved even in chronic arthritis is well-supported. Gram stains are more definitive in staphylococcal arthritis caused by gram-positive bacteria than in bacterial arthritis due to gram-negative bacteria. In the latter situation where gram-negative bacilli are the problem, Gram stains are helpful for 50% of the patients; they are only helpful for 25% of the patients, however, where gram-negative gonococci are the problem. In arthritis due to gram-positive Staphylococci. Gramstained smears are positive for 75% of the patients.

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