Segregative Clustering of Lo and Ld Membrane Microdomains Induced by Local pH Gradients in GM1-Containing Giant Vesicles: A Lipid Model for Cellular Polarization

Langmuir ◽  
2012 ◽  
Vol 28 (47) ◽  
pp. 16327-16337 ◽  
Author(s):  
Galya Staneva ◽  
Nicolas Puff ◽  
Michel Seigneuret ◽  
Hélène Conjeaud ◽  
Miglena I. Angelova
Keyword(s):  
Membrane Microdomains ◽  
Giant Vesicles ◽  
Ph Gradients ◽  
Cellular Polarization ◽  
Local Ph

Tuning the Photoluminescence of DNA-Wrapped Carbon Nanotubes by pH

2019 ◽  
Author(s):  
Niyousha Mohammadshafie
Keyword(s):  
Carbon Nanotubes ◽  
Living Cells ◽  
Microfluidic Channels ◽  
Ph Gradients ◽  
Local Ph ◽  
Dna Wrapping

These findings contribute in several ways to our understanding of DNA wrapping structure on the encased SWCNT and provide a basis for design of nanotube-based sensors for detecting local pH gradients in restricted environments, such as in living cells and microfluidic channels.

Microaligned collagen matrices by hydrodynamic focusing: controlling the pH-induced self-assembly

2005 ◽  
Vol 898 ◽  
Author(s):  
Sarah Köester ◽  
Jennie B Leach ◽  
Thomas Pfohl ◽  
Joyce Y Wong
Keyword(s):  
Self Assembly ◽  
Type I Collagen ◽  
Polarized Light ◽  
Type I ◽  
Hydrodynamic Focusing ◽  
Microfluidic Mixing ◽  
Ph Gradients ◽  
The Hierarchical Structure ◽  
Local Ph

AbstractThe hierarchical structure of type I collagen fibrils is a key contributor to the mechanical properties of the extracellular matrix (ECM). It is known that the process of in vitro fibrillogenesis strongly depends on the pH of the collagen solution. To date, there are few methods available for precisely controlling and investigating the dependence of collagen fibril assembly on the local pH. The objective of this work was to create highly defined pH gradients to systematically determine the effects of local pH on microscale collagen fibrillogenesis and alignment. We use a microfluidic mixing device to create a diffusion controlled pH gradient, which in turn initiates the self-assembly and concurrent flow-alignment of soluble collagen. Finite element method simulations of the hydrodynamic and diffusive phenomena are used to calculate the local concentrations of the components involved in the reaction. We develop a model to analytically calculate the local pH in the microfluidic device from these concentrations. A comparison with the experimental results from polarized light microscopy are in good agreement with the simulations.

Tuning the Photoluminescence of DNA-Wrapped Carbon Nanotubes by pH

2019 ◽  
Author(s):  
Niyousha Mohammadshafie
Keyword(s):  
Carbon Nanotubes ◽  
Living Cells ◽  
Microfluidic Channels ◽  
Ph Gradients ◽  
Local Ph ◽  
Dna Wrapping

These findings contribute in several ways to our understanding of DNA wrapping structure on the encased SWCNT and provide a basis for design of nanotube-based sensors for detecting local pH gradients in restricted environments, such as in living cells and microfluidic channels.

scholarly journals Light-Addressable Actuator-Sensor Platform for Monitoring and Manipulation of pH Gradients in Microfluidics: A Case Study with the Enzyme Penicillinase

Biosensors ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 171
Author(s):  
Rene Welden ◽  
Melanie Jablonski ◽  
Christina Wege ◽  
Michael Keusgen ◽  
Patrick Hermann Wagner ◽  
...  
Keyword(s):  
Reaction Rate ◽  
Enzymatic Reaction ◽  
Microfluidic Channel ◽  
Ph Gradients ◽  
Ph Influence ◽  
Sensor Platform ◽  
Local Ph ◽  
Scanning Electron ◽  
Light Addressable Potentiometric Sensor

The feasibility of light-addressed detection and manipulation of pH gradients inside an electrochemical microfluidic cell was studied. Local pH changes, induced by a light-addressable electrode (LAE), were detected using a light-addressable potentiometric sensor (LAPS) with different measurement modes representing an actuator-sensor system. Biosensor functionality was examined depending on locally induced pH gradients with the help of the model enzyme penicillinase, which had been immobilized in the microfluidic channel. The surface morphology of the LAE and enzyme-functionalized LAPS was studied by scanning electron microscopy. Furthermore, the penicillin sensitivity of the LAPS inside the microfluidic channel was determined with regard to the analyte’s pH influence on the enzymatic reaction rate. In a final experiment, the LAE-controlled pH inhibition of the enzyme activity was monitored by the LAPS.

Local pH gradients and the selectivity of fast reactions. I: Mathematical model of micromixing

1988 ◽  
Vol 43 (8) ◽  
pp. 1941-1948 ◽  
Author(s):  
J.R. Bourne ◽  
H. Gablinger ◽  
K. Ravindranath
Keyword(s):  
Mathematical Model ◽  
Ph Gradients ◽  
Fast Reactions ◽  
Local Ph

Fluoride renal clearance: a pH-dependent event

1976 ◽  
Vol 230 (2) ◽  
pp. 527-532 ◽  
Author(s):  
GM Whitford ◽  
DH Pashley ◽  
GI Stringer
Keyword(s):  
Renal Clearance ◽  
Flow Rate ◽  
Tubular Reabsorption ◽  
Urine Flow ◽  
Distal Nephron ◽  
Urinary Ph ◽  
Ph Gradients ◽  
Ph Dependent ◽  
Main Determinants ◽  
Local Ph

The renal clearance of fluoride (CF) was studied in pentobarbital-anesthetized rats. Urine flow rate and chloride clearance, previously thought to be the main determinants of CF, were readily dissociated from CF. Neither the clearance of sodium nor the excretion of potassium correlated consistently with CF. In experiments designed to manipulate urinary pH, viz., the administration of NaHCO3 or NH4Cl, acetazolamide, and mannitol, CF correlated closely with urinary pH. At a urinary pH of 5.0-k96, CF/GFR averaged less than 5%, while at a urinary pH of approximately 7.6, mean CF/GFR exceeded 65%. The data suggest that 35-45% of the filtered fluoride is reabsorbed in the proximal tubule, regardless of the final urinary pH, while in acidosis the majority of fluoride reabsorption occurs in the distal nephron. The results suggest that the tubular reabsorption of fluoride is inversely related to tubular fluid pH. Fluoride reabsorption seems to occur by nonionic diffusion, apparently as hydrogen fluoride. Depending on local pH gradients, it may occur along the entire nephron.

Sign in / Sign up

Export Citation Format

Share Document