Multilayer films composed of phenylboronic acid-modified dendrimers sensitive to glucose under physiological conditions

2014 ◽  
Vol 2 (35) ◽  
pp. 5809 ◽  
Author(s):  
Ryota Watahiki ◽  
Katsuhiko Sato ◽  
Keisuke Suwa ◽  
Satoshi Niina ◽  
Yuya Egawa ◽  
...  
Keyword(s):  
Phenylboronic Acid ◽  
Multilayer Films ◽  
Physiological Conditions

scholarly journals Optical glucose sensors based on hexagonally-packed 2.5-dimensional photonic concavities imprinted in phenylboronic acid functionalized hydrogel films

RSC Advances ◽  
2017 ◽  
Vol 7 (85) ◽  
pp. 53916-53924 ◽  
Author(s):  
Magdalena Bajgrowicz-Cieslak ◽  
Yousef Alqurashi ◽  
Mohamed Ismail Elshereif ◽  
Ali K. Yetisen ◽  
Muhammad Umair Hassan ◽  
...  
Keyword(s):  
Phenylboronic Acid ◽  
Glucose Sensors ◽  
Physiological Conditions ◽  
Glucose Levels ◽  
Hydrogel Films

A glucose-responsive hydrogel that changes its volume when exposed to different glucose concentrations was used to measure the glucose levels under physiological conditions.

Glucose-induced decomposition of layer-by-layer films composed of phenylboronic acid-bearing poly(allylamine) and poly(vinyl alcohol) under physiological conditions

2015 ◽  
Vol 3 (39) ◽  
pp. 7796-7802 ◽  
Author(s):  
Katsuhiko Sato ◽  
Mao Takahashi ◽  
Megumi Ito ◽  
Eiichi Abe ◽  
Jun-Ichi Anzai
Keyword(s):  
Glucose Oxidase ◽  
Vinyl Alcohol ◽  
Phenylboronic Acid ◽  
Poly Vinyl Alcohol ◽  
Layer By Layer ◽  
Physiological Conditions ◽  
Induced Decomposition

Phenylboronic acid-bearing poly(allylamine)/poly(vinyl alcohol) layer-by-layer films coupled with glucose oxidase decomposed in the presence of glucose under physiological conditions.

scholarly journals Preparation of Microparticles Capable of Glucose-Induced Insulin Release under Physiological Conditions

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1164 ◽  
Author(s):  
Kentaro Yoshida ◽  
Kazuma Awaji ◽  
Seira Shimizu ◽  
Miku Iwasaki ◽  
Yuki Oide ◽  
...  
Keyword(s):  
Boronic Acid ◽  
Oxidation Reaction ◽  
Shikimic Acid ◽  
Multilayer Films ◽  
Electrostatic Repulsion ◽  
Layer By Layer ◽  
Sensitive Layer ◽  
Boronate Ester ◽  
Physiological Conditions ◽  
Phenyl Boronic Acid

Hydrogen peroxide (H2O2)-sensitive layer-by-layer films were prepared based on combining phenyl boronic acid (PBA)-modified poly(allylamine) (PAH) with shikimic acid (SA)-modified-PAH through boronate ester bonds. These PBA-PAH/SA-PAH multilayer films could be prepared in aqueous solutions at pH 7.4 and 9.0 in the presence of NaCl. It is believed that the electrostatic repulsion between the SA-PAH and PBA-PAH was diminished and the formation of ester bonds between the SA and PBA was promoted in the presence of NaCl. These films readily decomposed in the presence of H2O2 because the boronate ester bonds were cleaved by an oxidation reaction. In addition, SA-PAH/PBA-PAH multilayer films combined with glucose oxidase (GOx) were decomposed in the presence of glucose because GOx catalyzes the oxidation of D-glucose to generate H2O2. The surfaces of CaCO3 microparticles were coated with PAH/GOx/(SA-PAH/PBA-PAH)5 films that absorbed insulin. A 1 mg quantity of these particles released up to 10 μg insulin in the presence 10 mM glucose under physiological conditions.

Ultrastructure of Giant Mitochondria and Their Inclusions in Schwann Cells of Bovine Splenic Nerve

1974 ◽  
Vol 32 ◽  
pp. 194-195
Author(s):  
Å. Thureson-Klein
Keyword(s):  
Schwann Cells ◽  
Cell Organelles ◽  
Giant Mitochondria ◽  
Matrix Density ◽  
Physiological Conditions ◽  
Unmyelinated Axons ◽  
Internal Structures ◽  
Structural Abnormalities ◽  
Cytotoxic Compounds ◽  
Cell Components

Giant mitochondria of various shapes and with different internal structures and matrix density have been observed in a great number of tissues including nerves. In most instances, the presence of giant mitochondria has been associated with a known disease or with abnormal physiological conditions such as anoxia or exposure to cytotoxic compounds. In these cases degenerative changes occurred in other cell organelles and, therefore the giant mitochondria also were believed to be induced structural abnormalities.Schwann cells ensheating unmyelinated axons of bovine splenic nerve regularly contain giant mitochondria in addition to the conventional smaller type (Fig. 1). These nerves come from healthy inspected animals presumed not to have been exposed to noxious agents. As there are no drastic changes in the small mitochondria and because other cell components also appear reasonably well preserved, it is believed that the giant mitochondria are normally present jin vivo and have not formed as a post-mortem artifact.

Freeze-fracture observations on changes in the distribution of Filipin-sterol complexes during epididymal maturation and capacitation of boar spermatozoa

1990 ◽  
Vol 48 (3) ◽  
pp. 90-91
Author(s):  
N. Seki ◽  
Y. Toyama ◽  
T. Nagano
Keyword(s):  
Plasma Membrane ◽  
Essential Role ◽  
Freeze Fracture ◽  
Final Concentration ◽  
Freeze Fracturing ◽  
Physiological Conditions ◽  
Epididymal Maturation ◽  
Cacodylate Buffer ◽  
Sperm Membrane ◽  
Boar Spermatozoa

It is believed that i ntramembra.nous sterols play an essential role in membrane stability and permeability. To investigate the distribution changes of sterols in sperm membrane during epididymal maturation and capacitation, filipin has been used as a cytochemical probe for the detection for membrane sterols. Using this technique in combination with freeze fracturing, we examined the boar spermatozoa under various physiological conditions.The spermatozoa were collected from: 1) caput, corpus and cauda epididymides, 2) sperm rich fraction of ejaculates, and 3)the uterus 2hr after natural coition. They were fixed with 2.5% glutaraldehyde in 0.05M cacodylate buffer (pH 7.4), and treated with the filipin solution (final concentration : 0.02.0.05%) for 24hr at 4°C with constant agitation. After the filipin treatment, replicas were made by conventional freeze-fracture technique. The density of filipin-sterol complexes (FSCs) was determined in the E face of the plasma membrane of head regions.

Fabrication and characterization - by High Resolution Electron Microscopy and atom probe microanalysis - of Co-based metallic multilayer films

1990 ◽  
Vol 48 (4) ◽  
pp. 772-773
Author(s):  
Amanda K. Petford-Long ◽  
A. Cerezo ◽  
M.G. Hetherington
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Atom Probe ◽  
Multilayer Films ◽  
Interface Roughness ◽  
Probe Field ◽  
Resolution Electron ◽  
Potential Applications ◽  
Field Ion Microscope

The fabrication of multilayer films (MLF) with layer thicknesses down to one monolayer has led to the development of materials with unique properties not found in bulk materials. The properties of interest depend critically on the structure and composition of the films, with the interfacial regions between the layers being of particular importance. There are a number of magnetic MLF systems based on Co, several of which have potential applications as perpendicular magnetic (e.g Co/Cr) or magneto-optic (e.g. Co/Pt) recording media. Of particular concern are the effects of parameters such as crystallographic texture and interface roughness, which are determined by the fabrication conditions, on magnetic properties and structure.In this study we have fabricated Co-based MLF by UHV thermal evaporation in the prechamber of an atom probe field-ion microscope (AP). The multilayers were deposited simultaneously onto cobalt field-ion specimens (for AP and position-sensitive atom probe (POSAP) microanalysis without exposure to atmosphere) and onto the flat (001) surface of oxidised silicon wafers (for subsequent study in cross-section using high-resolution electron microscopy (HREM) in a JEOL 4000EX. Deposi-tion was from W filaments loaded with material in the form of wire (Co, Fe, Ni, Pt and Au) or flakes (Cr). The base pressure in the chamber was around 8×10−8 torr during deposition with a typical deposition rate of 0.05 - 0.2nm/s.

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