scholarly journals Imaging-Guided Delivery of a Hydrophilic Drug to Eukaryotic Cells Based on Its Hydrophobic Ion Pairing with Poly(hexamethylene guanidine) in a Maleated Chitosan Carrier

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7426
Author(s):  
Sofia A. Zakharenkova ◽  
Marina I. Lebedeva ◽  
Alexandra N. Lebedeva ◽  
Irina A. Doroshenko ◽  
Ksenya Yu Vlasova ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Near Infrared ◽  
Ion Pairs ◽  
Laser Scanning Microscopy ◽  
Breast Adenocarcinoma ◽  
Confocal Laser ◽  
Counter Ion ◽  
Hydrophilic Drug ◽  
Model Drug ◽  
Novel Strategy

Imaging-guided delivery is developed for hydrophobic drugs, and to a much lesser extent, hydrophilic ones. In this work we have designed a novel strategy for real-time monitoring of hydrophilic drug delivery. Traditionally, the drug and the dye are covalently attached to a nanocarrier or are electrostatically adsorbed. Recently, we found an efficient way to bind the drug by ion-paring with an appropriate counter-ion to form the aggregate that embeds a hydrophobic dye with a considerable fluorescence enhancement. We synthesized a series of carbocyanine dyes of hydrophobicity sufficient for solubilization in hydrophobic ion pairs, which restores their emission in the near-infrared (NIR) region upon the formation of the ternary aggregates. To avoid using toxic surfactants, we applied an amphiphilic polymer-oligomer poly(hexamethylene guanidine) (PHMG) as a counter-ion. Сeftriaxone was used as a model hydrophilic drug ensuring the highest fluorescent signal. The so-formed drug–counter-ion–dye aggregates were encapsulated into a cross-linked maleated chitosan carrier. Confocal laser scanning microscopy (CLSM) studies have demonstrated internalization of the encapsulated model drug by breast adenocarcinoma cells at 40 min after treatment. These results suggest the potential application of hydrophobic ion pairs containing an NIR dye in imaging-guided delivery of hydrophilic compounds.

scholarly journals Temperature-Regulated Formation of Mycelial Mat-Like Biofilms by Legionella pneumophila

2006 ◽  
Vol 72 (2) ◽  
pp. 1613-1622 ◽  
Author(s):  
Zhenyu Piao ◽  
Chun Chau Sze ◽  
Oksana Barysheva ◽  
Ken-ichiro Iida ◽  
Shin-ichi Yoshida
Keyword(s):  
Legionella Pneumophila ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
C Cells ◽  
Planktonic Cells ◽  
Legionnaires Disease ◽  
Novel Strategy ◽  
Glass Surfaces

ABSTRACT Fifty strains representing 38 species of the genus Legionella were examined for biofilm formation on glass, polystyrene, and polypropylene surfaces in static cultures at 25°C, 37°C, and 42°C. Strains of Legionella pneumophila, the most common causative agent of Legionnaires' disease, were found to have the highest ability to form biofilms among the test strains. The quantity, rate of formation, and adherence stability of L. pneumophila biofilms showed considerable dependence on both temperature and surface material. Glass and polystyrene surfaces gave between two- to sevenfold-higher yields of biofilms at 37°C or 42°C than at 25°C; conversely, polypropylene surface had between 2 to 16 times higher yields at 25°C than at 37°C or 42°C. On glass surfaces, the biofilms were formed faster but attached less stably at 37°C or 42°C than at 25°C. Both scanning electron microscopy and confocal laser scanning microscopy revealed that biofilms formed at 37°C or 42°C were mycelial mat like and were composed of filamentous cells, while at 25°C, cells were rod shaped. Planktonic cells outside of biofilms or in shaken liquid cultures were rod shaped. Notably, the filamentous cells were found to be multinucleate and lacking septa, but a recA null mutant of L. pneumophila was unaffected in its temperature-regulated filamentation within biofilms. Our data also showed that filamentous cells were able to rapidly give rise to a large number of short rods in a fresh liquid culture at 37°C. The possibility of this biofilm to represent a novel strategy by L. pneumophila to compete for proliferation among the environmental microbiota is discussed.

scholarly journals Substantial near-infrared radiation-driven photosynthesis of chlorophyll f-containing cyanobacteria in a natural habitat

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Michael Kühl ◽  
Erik Trampe ◽  
Maria Mosshammer ◽  
Michael Johnson ◽  
Anthony WD Larkum ◽  
...  
Keyword(s):  
Infrared Radiation ◽  
Laser Scanning ◽  
Near Infrared ◽  
Natural Habitat ◽  
Red Light ◽  
Laser Scanning Microscopy ◽  
Oxygenic Photosynthesis ◽  
Confocal Laser ◽  
Near Infrared Radiation ◽  
Molecular Physiology

Far-red absorbing chlorophylls are constitutively present as chlorophyll (Chl) d in the cyanobacterium Acaryochloris marina, or dynamically expressed by synthesis of Chl f, red-shifted phycobiliproteins and minor amounts of Chl d via far-red light photoacclimation in a range of cyanobacteria, which enables them to use near-infrared-radiation (NIR) for oxygenic photosynthesis. While the biochemistry and molecular physiology of Chl f-containing cyanobacteria has been unraveled in culture studies, their ecological significance remains unexplored and no data on their in situ activity exist. With a novel combination of hyperspectral imaging, confocal laser scanning microscopy, and nanoparticle-based O2 imaging, we demonstrate substantial NIR-driven oxygenic photosynthesis by endolithic, Chl f-containing cyanobacteria within natural beachrock biofilms that are widespread on (sub)tropical coastlines. This indicates an important role of NIR-driven oxygenic photosynthesis in primary production of endolithic and other shaded habitats.

scholarly journals Multifunctional Magneto-Plasmonic Fe3O4/Au Nanocomposites: Approaching Magnetophoretically-Enhanced Photothermal Therapy

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1113
Author(s):  
Iuliia Mukha ◽  
Oksana Chepurna ◽  
Nadiia Vityuk ◽  
Alina Khodko ◽  
Liudmyla Storozhuk ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Laser Irradiation ◽  
Photothermal Therapy ◽  
Laser Scanning ◽  
Near Infrared ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Photochemical Reduction ◽  
Induced Aggregation

Magneto-plasmonic nanocomposites can possess properties inherent to both individual components (iron oxide and gold nanoparticles) and are reported to demonstrate high potential in targeted drug delivery and therapy. Herein, we report on Fe3O4/Au magneto-plasmonic nanocomposites (MPNC) synthesized with the use of amino acid tryptophan via chemical and photochemical reduction of Au ions in the presence of nanosized magnetite. The magnetic field (MF) induced aggregation was accompanied by an increase in the absorption in the near-infrared (NIR) spectral region, which was demonstrated to provide an enhanced photothermal (PT) effect under NIR laser irradiation (at 808 nm). A possibility for therapeutic application of the MPNC was illustrated using cancer cells in vitro. Cultured HeLa cells were treated by MPNC in the presence of MF and without it, following laser irradiation and imaging using confocal laser scanning microscopy. After scanning laser irradiation of the MPNC/MF treated cells, a formation and rise of photothermally-induced microbubbles on the cell surfaces was observed, leading to a damage of the cell membrane and cell destruction. We conclude that the synthesized magneto-plasmonic Fe3O4/Au nanosystems exhibit magnetic field-induced reversible aggregation accompanied by an increase in NIR absorption, allowing for an opportunity to magnetophoretically control and locally enhance a NIR light-induced thermal effect, which holds high promise for the application in photothermal therapy.

Near-infrared confocal laser scanning microscopy of bladder tissue in vivo

Urology ◽  
1999 ◽  
Vol 53 (4) ◽  
pp. 853-857 ◽  
Author(s):  
Frank Koenig ◽  
Salvador González ◽  
W.Matthew White ◽  
Michael Lein ◽  
Milind Rajadhyaksha
Keyword(s):  
Confocal Laser Scanning Microscopy ◽  
Laser Scanning ◽  
Near Infrared ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Scanning Microscopy ◽  
Confocal Laser ◽  
Bladder Tissue

scholarly journals Substantial near-infrared radiation-driven photosynthesis of chlorophyll f-containing cyanobacteria in a natural habitat

2019 ◽  
Author(s):  
Michael Kühl ◽  
Erik Trampe ◽  
Maria Mosshammer ◽  
Michael Johnson ◽  
Anthony W. D. Larkum ◽  
...  
Keyword(s):  
Infrared Radiation ◽  
Laser Scanning ◽  
Near Infrared ◽  
Natural Habitat ◽  
Red Light ◽  
Laser Scanning Microscopy ◽  
Oxygenic Photosynthesis ◽  
Confocal Laser ◽  
Near Infrared Radiation ◽  
Molecular Physiology

AbstractFar-red absorbing chlorophylls are constitutively present as Chl d in the cyanobacterium Acaryochloris marina, or dynamically expressed by synthesis of Chl f and red-shifted phycobilins via far-red light photoacclimation in a range of cyanobacteria, which enables them to use near-infrared-radiation (NIR) for oxygenic photosynthesis. While the biochemistry and molecular physiology of Chl f-containing cyanobacteria has been unraveled in culture studies, their ecological significance remains unexplored and no data on their in situ activity exist. With a novel combination of hyperspectral imaging, confocal laser scanning microscopy, and nanoparticle-based O2 imaging, we demonstrate substantial NIR-driven oxygenic photosynthesis by endolithic, Chl f-containing cyanobacteria within natural beachrock biofilms that are widespread on (sub)tropical coastlines. This indicates an important role of NIR-driven oxygenic photosynthesis in primary production of endolithic and other shaded habitats.Impact statementCyanobacteria with chlorophyll f show substantial near-infrared radiation-driven photosynthesis in intertidal habitats.

scholarly journals Effect of Photothermal Therapy with Indocyanine Green in Multispecies Biofilm

2021 ◽  
Vol 48 (1) ◽  
pp. 21-30
Author(s):  
Myunghwan Kim ◽  
Howon Park ◽  
Juhyun Lee ◽  
Hyunwoo Seo ◽  
Siyoung Lee
Keyword(s):  
Indocyanine Green ◽  
Diode Laser ◽  
Laser Scanning ◽  
Near Infrared ◽  
Irradiation Time ◽  
Qualitative Evaluation ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Measured Temperature ◽  
Antibacterial Effects

The purpose of this study is to investigate the antibacterial effects of indocyanine green (ICG) and near-infrared diode lasers on multispecies biofilms.Multispecies biofilms of <i>Streptococcus mutans</i>, <i>Lactobacillus casei</i> and <i>Candida albicans</i> were treated with different irradiation time using photosensitizer ICG and 808 nm near-infrared diode laser. Colony forming unit (CFU) was measured, and qualitative evaluation of biofilm was performed with confocal laser scanning microscopy (CLSM). Temperature measurement was conducted to evaluate photothermal effect.In the groups using ICG and diode laser, reduction in CFU was statistically significant, but the difference in antibacterial effect on <i>L. casei</i> and <i>C. albicans</i> with irradiation time was not significant, and similar results were confirmed with CLSM. Groups with ICG and diode laser showed higher temperature elevation than groups without ICG, and results of measured temperature were similar to the range of hyperthermia.In conclusion, ICG and near-infrared diode laser showed antibacterial effects on multispecies biofilms, but studies on protocol are necessary for clinical application.

scholarly journals In Vitro Evidences of Different Fibroblast Morpho-Functional Responses to Red, Near-Infrared and Violet-Blue Photobiomodulation: Clues for Addressing Wound Healing

2020 ◽  
Vol 10 (21) ◽  
pp. 7878
Author(s):  
Flaminia Chellini ◽  
Alessia Tani ◽  
Sandra Zecchi-Orlandini ◽  
Marco Giannelli ◽  
Chiara Sassoli
Keyword(s):  
Wound Healing ◽  
Laser Scanning ◽  
Near Infrared ◽  
Smooth Muscle Actin ◽  
Focal Adhesions ◽  
Laser Scanning Microscopy ◽  
Wound Management ◽  
Matrix Metalloproteinase 2 ◽  
Confocal Laser ◽  
Functional Responses

Although photobiomodulation (PBM) has proven promising to treat wounds, the lack of univocal guidelines and of a thorough understanding of light–tissue interactions hampers its mainstream adoption for wound healing promotion. This study compared murine and human fibroblast responses to PBM by red (635 ± 5 nm), near-infrared (NIR, 808 ± 1 nm), and violet-blue (405 ± 5 nm) light (0.4 J/cm2 energy density, 13 mW/cm2 power density). Cell viability was not altered by PBM treatments. Light and confocal laser scanning microscopy and biochemical analyses showed, in red PBM irradiated cells: F-actin assembly reduction, up-regulated expression of Ki67 proliferation marker and of vinculin in focal adhesions, type-1 collagen down-regulation, matrix metalloproteinase-2 and metalloproteinase-9 expression/functionality increase concomitant to their inhibitors (TIMP-1 and TIMP-2) decrease. Violet-blue and even more NIR PBM stimulated collagen expression/deposition and, likely, cell differentiation towards (proto)myofibroblast phenotype. Indeed, these cells exhibited a higher polygonal surface area, stress fiber-like structures, increased vinculin- and phospho-focal adhesion kinase-rich clusters and α-smooth muscle actin. This study may provide the experimental groundwork to support red, NIR, and violet-blue PBM as potential options to promote proliferative and matrix remodeling/maturation phases of wound healing, targeting fibroblasts, and to suggest the use of combined PBM treatments in the wound management setting.

3-D imaging of cells using a confocal laser scanning microscope and digital image processing

1988 ◽  
Vol 46 ◽  
pp. 96-97
Author(s):  
Thomas M. Jovin ◽  
Michel Robert-Nicoud ◽  
Donna J. Arndt-Jovin ◽  
Thorsten Schormann
Keyword(s):  
Laser Scanning ◽  
Confocal Laser Scanning Microscope ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Scanning Microscope ◽  
Laser Scanning Microscope ◽  
Biochemical Processes ◽  
Adjacent Structures

Light microscopic techniques for visualizing biomolecules and biochemical processes in situ have become indispensable in studies concerning the structural organization of supramolecular assemblies in cells and of processes during the cell cycle, transformation, differentiation, and development. Confocal laser scanning microscopy offers a number of advantages for the in situ localization and quantitation of fluorescence labeled targets and probes: (i) rejection of interfering signals emanating from out-of-focus and adjacent structures, allowing the “optical sectioning” of the specimen and 3-D reconstruction without time consuming deconvolution; (ii) increased spatial resolution; (iii) electronic control of contrast and magnification; (iv) simultanous imaging of the specimen by optical phenomena based on incident, scattered, emitted, and transmitted light; and (v) simultanous use of different fluorescent probes and types of detectors.We currently use a confocal laser scanning microscope CLSM (Zeiss, Oberkochen) equipped with 3-laser excitation (u.v - visible) and confocal optics in the fluorescence mode, as well as a computer-controlled X-Y-Z scanning stage with 0.1 μ resolution.

Vacuoles Induced in Mammalian Cells by Helicobacter Cytotoxin are Acidic Organelles

1990 ◽  
Vol 48 (3) ◽  
pp. 168-169
Author(s):  
M. H. Chestnut ◽  
C. E. Catrenich
Keyword(s):  
Acridine Orange ◽  
Mammalian Cells ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Ulcer Disease ◽  
Gastroduodenal Disease ◽  
H Pylori

Helicobacter pylori is a non-invasive, Gram-negative spiral bacterium first identified in 1983, and subsequently implicated in the pathogenesis of gastroduodenal disease including gastritis and peptic ulcer disease. Cytotoxic activity, manifested by intracytoplasmic vacuolation of mammalian cells in vitro, was identified in 55% of H. pylori strains examined. The vacuoles increase in number and size during extended incubation, resulting in vacuolar and cellular degeneration after 24 h to 48 h. Vacuolation of gastric epithelial cells is also observed in vivo during infection by H. pylori. A high molecular weight, heat labile protein is believed to be responsible for vacuolation and to significantly contribute to the development of gastroduodenal disease in humans. The mechanism by which the cytotoxin exerts its effect is unknown, as is the intracellular origin of the vacuolar membrane and contents. Acridine orange is a membrane-permeant weak base that initially accumulates in low-pH compartments. We have used acridine orange accumulation in conjunction with confocal laser scanning microscopy of toxin-treated cells to begin probing the nature and origin of these vacuoles.

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