scholarly journals Magnetic Polyion Complex Micelles for Cell Toxicity Induced by Radiofrequency Magnetic Field Hyperthermia

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1014 ◽  
Author(s):  
Vo Nguyen ◽  
Marie-Claire De Pauw-Gillet ◽  
Mario Gauthier ◽  
Olivier Sandre
Keyword(s):  
Magnetic Field ◽  
Self Assembly ◽  
Laser Scanning ◽  
Colloidal Stability ◽  
Strong Dependence ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Field Exposure ◽  
Polyion Complex ◽  
Cell Internalization

Magnetic nanoparticles (MNPs) of magnetite (Fe3O4) were prepared using a polystyrene-graft-poly(2-vinylpyridine) copolymer (denoted G0PS-g-P2VP or G1) as template. These MNPs were subjected to self-assembly with a poly(acrylic acid)-block-poly(2-hydroxyethyl acrylate) double-hydrophilic block copolymer (DHBC), PAA-b-PHEA, to form water-dispersible magnetic polyion complex (MPIC) micelles. Large Fe3O4 crystallites were visualized by transmission electron microscopy (TEM) and magnetic suspensions of MPIC micelles exhibited improved colloidal stability in aqueous environments over a wide pH and ionic strength range. Biological cells incubated for 48 h with MPIC micelles at the highest concentration (1250 µg of Fe3O4 per mL) had a cell viability of 91%, as compared with 51% when incubated with bare (unprotected) MNPs. Cell internalization, visualized by confocal laser scanning microscopy (CLSM) and TEM, exhibited strong dependence on the MPIC micelle concentration and incubation time, as also evidenced by fluorescence-activated cell sorting (FACS). The usefulness of MPIC micelles for cellular radiofrequency magnetic field hyperthermia (MFH) was also confirmed, as the MPIC micelles showed a dual dose-dependent effect (concentration and duration of magnetic field exposure) on the viability of L929 mouse fibroblasts and U87 human glioblastoma epithelial cells.

Cell labeling efficiency of layer-by-layer self-assembly modified silica nanoparticles

2009 ◽  
Vol 24 (4) ◽  
pp. 1317-1321 ◽  
Author(s):  
Gang Liu ◽  
Jing Tian ◽  
Chen Liu ◽  
Hua Ai ◽  
Zhongwei Gu ◽  
...  
Keyword(s):  
Silica Nanoparticles ◽  
Self Assembly ◽  
Laser Scanning ◽  
Control Cell ◽  
Silica Nanoparticle ◽  
Laser Scanning Microscopy ◽  
Cell Labeling ◽  
Cell Uptake ◽  
Confocal Laser ◽  
Layer By Layer

In the present study, we compared cytotoxicity and cell uptake of silica nanoparticles with four different surface coatings generated through layer-by-layer self-assembly. Rabbit mesenchymal stem cells (rMSCs) were labeled with silica nanoparticles of different coatings including poly(ethyleneimine) (PEI), poly(allylamine hydrochloride) (PAH), poly(anetholesulfonic acid, sodium salt) (PAS), and dextran sulfate. The MTT [3-(4, 5-dimethylthiazol-2)-2, 5-diphenyl-2H-tetrazolium bromide] test was performed to quantify the cell biocompatibility. The cellular uptake of those silica nanoparticles was determined by flow cytometry and confocal laser scanning microscopy. The results showed that all examined silica nanoparticles were stable in aqueous phase with high monodispersity. Labeled rMSCs are unaffected in their viability, apoptosis, and differentiation capacities. The silica nanoparticle-coated synthetic polycations such as PEI or PAH have higher cell internalization than negatively charged polyelectrolytes. The ability to control cell uptake of different particles may have applications in cell labeling, cell separation, and other biomedical applications.

all-D proline-rich cell-penetrating peptides: a preliminary in vivo internalization study

2007 ◽  
Vol 35 (4) ◽  
pp. 794-796 ◽  
Author(s):  
S. Pujals ◽  
E. Sabidó ◽  
T. Tarragó ◽  
E. Giralt
Keyword(s):  
Self Assembly ◽  
Laser Scanning ◽  
White Blood Cells ◽  
Cell Penetrating Peptides ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Cell Penetrating ◽  
Peptide Derivatives ◽  
Degradation Problem

Proline-rich cell-penetrating peptides, particularly the SAP (sweet arrow peptide), (VRLPPP)3, have been proposed to be useful intracellular delivery vectors, as a result of their lack of cytotoxicity combined with their capacity to be internalized by cells. A common limitation of the therapeutic use of peptides is metabolic instability. In general, peptides are quickly degraded by proteases upon entry into the bloodstream. The use of all-D-peptide derivatives is emerging as a fruitful strategy to circumvent this degradation problem. In this context, we report on the internalization behaviour, protease-resistance enhancement and self-assembly properties of an all-D version of SAP [(vrlppp)3]. The cellular uptake of (vrlppp)3 was evaluated in an in vivo assay in mice. Both flow cytometry and confocal laser-scanning microscopy experiments showed that a carboxyfluoresceinated version of the molecule, carboxyfluorescein–(vrlppp)3, is internalized rapidly in white blood cells and kidney cells. Significant fluorescence was also detected in other organs such as the spleen and the liver. Finally, the toxicity of (vrlppp)3 was examined, and no significant differences in the main biochemical parameters nor in weight were detected compared with controls.

PHOSPHOLIPID ASSEMBLY ON SUPERPARAMAGNETIC NANOPARTICLES FOR THERMORESPONSIVE DRUG DELIVERY APPLICATIONS

Nano LIFE ◽  
2010 ◽  
Vol 01 (03n04) ◽  
pp. 251-261 ◽  
Author(s):  
CHRISTOPHER HUTH ◽  
DONGLU SHI ◽  
FENG WANG ◽  
DONALD CARRAHAR ◽  
JIE LIAN ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Drug Delivery ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Superparamagnetic Nanoparticles ◽  
Confocal Laser ◽  
Temperature Dependent ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Phosphate Buffered Saline

Thermoresponsive nanocomposites were prepared by immobilizing a 2–3 nm thick phospholipid layer on the surface of superparamagnetic Fe3O4 nanoparticles via high-affinity avidin/biotin interactions. Morphological and physicochemical surface properties were assessed using transmission electron microscopy, confocal laser scanning microscopy, differential scanning calorimetry, and attenuated total reflectance Fourier transform infrared spectroscopy. The zeta potential of Fe3O4 colloids in phosphate buffered saline (PBS) decreased from -23.6 to -5.0 mV as a consequence of phospholipid immobilization. Nevertheless, heating properties of these superparamagnetic nanoparticles within an alternating magnetic field were not significantly affected. Hyperthermia-relevant temperatures > 40°C were achieved within 10–15 min using a 7-mT magnetic field alternating at a frequency of 1 MHz. Loading of the surface-associated phospholipid layer with the hydrophobic dye dansylcadaverine was accomplished at an efficiency of 479 ng/mg Fe3O4 . Release of this drug surrogate was temperature-dependent, resulting in a 2.5-fold greater release rate when nanoparticles were exposed to a temperature above the experimentally determined melting temperature of 39.7°C. These data underline the feasibility of preparing novel, stimulus-induced drug delivery systems where payload release from a colloid-immobilized phospholipid assembly is triggered by hyperthermia.

scholarly journals Size-Dependent Internalization Efficiency of Macrophages from Adsorbed Nanoparticle-Based Monolayers

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1963
Author(s):  
Tatiana Petithory ◽  
Laurent Pieuchot ◽  
Ludovic Josien ◽  
Arnaud Ponche ◽  
Karine Anselme ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Raw 264.7 ◽  
Functional Coatings ◽  
Size Dependent ◽  
Cell Internalization ◽  
Biomedical Field ◽  
Scanning Electron

Functional coatings based on the assembly of submicrometric or nanoparticles are found in many applications in the biomedical field. However, these nanoparticle-based coatings are particularly fragile since they could be exposed to cells that are able to internalize nanoparticles. Here, we studied the efficiency of RAW 264.7 murine macrophages to internalize physisorbed silica nanoparticles as a function of time and particle size. This cell internalization efficiency was evaluated from the damages induced by the cells in the nanoparticle-based monolayer on the basis of scanning electron microscopy and confocal laser scanning microscopy observations. The internalization efficiency in terms of the percentage of nanoparticles cleared from the substrate is characterized by two size-dependent regimes. Additionally, we highlighted that a delay before internalization occurs, which increases with decreasing adsorbed nanoparticle size. This internalization is characterized by a minimal threshold that corresponds to 35 nm nanoparticles that are not internalized during the 12-h incubation considered in this work.

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.

Biomimetic Remineralization of Human Enamel in the Presence of Polyamidoamine Dendrimers in vitro

2015 ◽  
Vol 49 (3) ◽  
pp. 282-290 ◽  
Author(s):  
Liang Chen ◽  
He Yuan ◽  
Bei Tang ◽  
Kunneng Liang ◽  
Jiyao Li
Keyword(s):  
Self Assembly ◽  
Laser Scanning ◽  
Molecular Size ◽  
Nucleation Site ◽  
Laser Scanning Microscopy ◽  
Enamel Surface ◽  
Protein Crystal ◽  
Confocal Laser ◽  
Human Enamel

Poly(amidoamine) (PAMAM) dendrimers, known as artificial proteins, have unique and well-defined molecular size and structure. It has previously been used to mimic protein-crystal interaction during biomineralization. In this study, generation 4.5 (4.5G) PAMAM with carboxylic acid (PAMAM-COOH) was synthesized and utilized to remineralize the surface of etched enamel in vitro. Using confocal laser scanning microscopy, Fourier transform infrared spectroscopy, X-ray diffraction analysis and scanning electron microscopy we observed that 4.5G PAMAM-COOH can be absorbed on the etched enamel surface and that it can induce the formation of hydroxyapatite crystals with the same orientation as that of the enamel prisms on longitudinal and transversal enamel surfaces. The self-assembly behavior of PAMAM in the mineralization solution was also investigated and the result showed that 4.5G PAMAM can assemble to microribbon structure similar to the behavior of amelogenins. Therefore, we concluded that 4.5G PAMAM-COOH assemblies can act as the organic template on enamel surface and in mineralization solution to control the nucleation site and morphology of new-grown crystals to form the biomimetic structure of human enamel, which may open a new way for repairing damaged enamel.

scholarly journals Combination Design of Time-Dependent Magnetic Field and Magnetic Nanocomposites to Guide Cell Behavior

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 577 ◽  
Author(s):  
Teresa Russo ◽  
Valentina Peluso ◽  
Antonio Gloria ◽  
Olimpia Oliviero ◽  
Laura Rinaldi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Tissue Engineering ◽  
Fe3o4 Nanoparticles ◽  
Laser Scanning ◽  
Peak Load ◽  
Laser Scanning Microscopy ◽  
Time Dependent ◽  
Confocal Laser ◽  
Magnetic Nanocomposites ◽  
Wide Range

The concept of magnetic guidance is still challenging and has opened a wide range of perspectives in the field of tissue engineering. In this context, magnetic nanocomposites consisting of a poly(ε-caprolactone) (PCL) matrix and iron oxide (Fe3O4) nanoparticles were designed and manufactured for bone tissue engineering. The mechanical properties of PCL/Fe3O4 (80/20 w/w) nanocomposites were first assessed through small punch tests. The inclusion of Fe3O4 nanoparticles improved the punching properties as the values of peak load were higher than those obtained for the neat PCL without significantly affecting the work to failure. The effect of a time-dependent magnetic field on the adhesion, proliferation, and differentiation of human mesenchymal stem cells (hMSCs) was analyzed. The Alamar Blue assay, confocal laser scanning microscopy, and image analysis (i.e., shape factor) provided information on cell adhesion and viability over time, whereas the normalized alkaline phosphatase activity (ALP/DNA) demonstrated that the combination of a time-dependent field with magnetic nanocomposites (PCL/Fe3O4 Mag) influenced cell differentiation. Furthermore, in terms of extracellular signal-regulated kinase (ERK)1/2 phosphorylation, an insight into the role of the magnetic stimulation was reported, also demonstrating a strong effect due the combination of the magnetic field with PCL/Fe3O4 nanocomposites (PCL/Fe3O4 Mag).

scholarly journals The cyclodextrin inclusion complex-containing biodegradable polymeric systems as drug carrier

2019 ◽  
Vol 17 (6) ◽  
pp. 61
Author(s):  
Trâm Trương Lê Bích
Keyword(s):  
Block Copolymers ◽  
Self Assembly ◽  
Laser Scanning ◽  
Drug Carrier ◽  
Drug Carriers ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Hep G2 ◽  
Polymeric Systems ◽  
Vis Spectroscopy

This article shows that the supramolecular micelle assemblies from PCL-b-P4VP block copolymers with α-CD via self-assembly of inclusion complexes in an aqueous solution. Dox encapsulation and the release at different pH of supramolecular micelle assemblies from poly (ε-caprolactone-block-4-vinylpyridine) (PCL-b-P4VP) block copolymers with α-CD showed excellent cytocompatibility. Dox was successfully loaded into the micelles with a loading content of 14.4% and loading efficiency of 28.9% by using UV-Vis spectroscopy (UV). The Dox loaded micelles showed lower cytotoxicity than free drugs, and could efficiently deliver and release the drug into human hepatocellular carcinoma (Hep-G2) cells as confirmed by confocal laser scanning microscopy (CLSM). These properties make the polymer micelles attractive as drug carriers for pharmaceutical applications.

scholarly journals Synthesis of Water-Soluble Iridium (III)-Containing Nanoparticles for Biological Applications

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Huanzhi Hou ◽  
Pengfei Sun ◽  
Quli Fan ◽  
Xiaomei Lu ◽  
Cheng Xue ◽  
...  
Keyword(s):  
Self Assembly ◽  
Laser Scanning ◽  
Morphological Characterization ◽  
Fluorescent Imaging ◽  
Water Soluble ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Biological Applications

Water-soluble nanoparticles (Ir/PGlc-NP, Ir/β-1,3-glucan-NP) based on water-soluble glycopolymers (PGlc),β-1,3-glucan polysaccharide, and conjugated phosphorescent Ir (III) complexes were successfully synthesized by self-assembly. The obtained nanoparticles have good spherical morphological characterization with a mean diameter of 50 nm measured by TEM. Ir/PGlc-NP and Ir/β-1,3-glucan-NP showed the same emission maxima at 565 nm in aqueous solution and both caused effective apoptosis and death of HepG2 and Hela cells after being irradiated at 445 nm for 30 min in vitro. Fluorescence cellular imaging was conducted by confocal laser scanning microscopy (CLSM) using HepG2 cells as the model cell in which the nanoparticles had successfully entered into the cytoplasm with high brightness. Furthermore, after injecting the nanoparticles into live mice in vivo, the real-time fluorescence imaging as well as the nanoparticles distribution in organs at 24 hours after administration indicated that these nanoparticles can serve as fluorescent imaging contrast for further biological applications.

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.

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