scholarly journals Matrix fixed-charge density as determined by magnetic resonance microscopy of bioreactor-derived hyaline cartilage correlates with biochemical and biomechanical properties

2003 ◽  
Vol 48 (4) ◽  
pp. 1047-1056 ◽  
Author(s):  
Chih-Tung Chen ◽  
Kenneth W. Fishbein ◽  
Peter A. Torzilli ◽  
Amy Hilger ◽  
Richard G. S. Spencer ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Charge Density ◽  
Hyaline Cartilage ◽  
Biomechanical Properties ◽  
Fixed Charge ◽  
Magnetic Resonance Microscopy ◽  
Fixed Charge Density

scholarly journals Hyaluronidase reduced edema after experimental traumatic brain injury

2019 ◽  
Vol 40 (10) ◽  
pp. 2026-2037 ◽  
Author(s):  
Patricia M Washington ◽  
Changhee Lee ◽  
Mary Kate R Dwyer ◽  
Elisa E Konofagou ◽  
Steven G Kernie ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Magnetic Resonance ◽  
Charge Density ◽  
Fixed Charge ◽  
Resonance Imaging ◽  
Fixed Charge Density

Cerebral edema and the subsequent increased intracranial pressure are associated with mortality and poor outcome following traumatic brain injury. Previous in vitro studies have shown that the Gibbs-Donnan effect, which describes the tendency of a porous, negatively charged matrix to attract positive ions and water, applies to brain tissue and that enzymatic reduction of the fixed charge density can prevent tissue swelling. We tested whether hyaluronidase, an enzyme that degrades the large, negatively charged glycosaminoglycan hyaluronan, could reduce brain edema after traumatic brain injury. In vivo, intracerebroventricular injection of hyaluronidase after controlled cortical impact in mice reduced edema in the ipsilateral hippocampus at 24 h by both the wet-weight/dry-weight method (78.15 ± 0.65% vs. 80.4 ± 0.46%; p < 0.01) and T2-weighted magnetic resonance imaging (13.88 ± 3.09% vs. 29.23 ± 6.14%; p < 0.01). Hyaluronidase did not adversely affect blood–brain-barrier-integrity measured by dynamic contrast-enhanced magnetic resonance imaging, nor did hyaluronidase negatively affect functional recovery after controlled cortical impact measured with the rotarod or Morris water maze tasks. Reduction of fixed charge density by hyaluronidase was confirmed in cortical explants in vitro (5.46 ± 1.15 µg/mg vs. 7.76 ± 1.87 µg/mg; p < 0.05). These data demonstrate that targeting the fixed charge density with hyaluronidase reduced edema in an in vivo mouse model of traumatic brain injury.

Evaluation of Negative Fixed-Charge Density in Tissue-Engineered Cartilage by Quantitative MRI and Relationship With Biomechanical Properties

2010 ◽  
Vol 132 (7) ◽  
Author(s):  
Shogo Miyata ◽  
Kazuhiro Homma ◽  
Tomokazu Numano ◽  
Tetsuya Tateishi ◽  
Takashi Ushida
Keyword(s):  
Charge Density ◽  
Dynamic Modulus ◽  
Biomechanical Properties ◽  
Compressive Modulus ◽  
Fixed Charge ◽  
Cartilage Tissue ◽  
Fixed Charge Density ◽  
Culture Time ◽  
Enhanced Mri ◽  
Engineered Cartilage

Applying tissue-engineered cartilage in a clinical setting requires noninvasive evaluation to detect the maturity of the cartilage. Magnetic resonance imaging (MRI) of articular cartilage has been widely accepted and applied clinically in recent years. In this study, we evaluated the negative fixed-charge density (nFCD) of tissue-engineered cartilage using gadolinium-enhanced MRI and determined the relationship between nFCD and biomechanical properties. To reconstruct cartilage tissue, articular chondrocytes from bovine humeral heads were embedded in agarose gel and cultured in vitro for up to 4 weeks. The nFCD of the cartilage was determined using the MRI gadolinium exclusion method. The equilibrium modulus was determined using a compressive stress relaxation test, and the dynamic modulus was determined by a dynamic compression test. The equilibrium compressive modulus and dynamic modulus of the tissue-engineered cartilage increased with an increase in culture time. The nFCD value—as determined with the [Gd-DTPA2−] measurement using the MRI technique—increased with culture time. In the regression analysis, nFCD showed significant correlations with equilibrium compressive modulus and dynamic modulus. From these results, gadolinium-enhanced MRI measurements can serve as a useful predictor of the biomechanical properties of tissue-engineered cartilage.

scholarly journals 23Na MRI accurately measures fixed charge density in articular cartilage

2002 ◽  
Vol 47 (2) ◽  
pp. 284-291 ◽  
Author(s):  
Erik M. Shapiro ◽  
Arijitt Borthakur ◽  
Alexander Gougoutas ◽  
Ravinder Reddy
Keyword(s):  
Articular Cartilage ◽  
Charge Density ◽  
Fixed Charge ◽  
Fixed Charge Density ◽  
23Na Mri

Fixed charge density and cartilage biomechanics

2002 ◽  
pp. 387-395
Author(s):  
Robert J. Wilkins ◽  
Bethan Hopewell ◽  
Jill P. G. Urban
Keyword(s):  
Charge Density ◽  
Fixed Charge ◽  
Fixed Charge Density ◽  
Cartilage Biomechanics ◽  
And Cartilage

Electrophysiology of renal capillary membranes: gel concept applied and Starling model challenged

1988 ◽  
Vol 254 (3) ◽  
pp. F364-F373 ◽  
Author(s):  
M. Wolgast ◽  
G. Ojteg
Keyword(s):  
Charge Density ◽  
Electrical Potential ◽  
Potential Gradient ◽  
Swelling Pressure ◽  
Porous Membrane ◽  
Fixed Charge ◽  
Fixed Charge Density ◽  
Capillary Membranes ◽  
External Forces ◽  
Gel Membranes

In the classical Starling model the hydrostatic pressure in the pores is generally lower than that in capillary plasma, a phenomenon that necessitates the assumption of a rigid porous membrane. In flexible gel membranes, the capillary pressure is suggested to be balanced by a gel swelling pressure generated by negative fixed charges. Regarding the fluid transfer, the transmembranous electrical potential gradient will generate a net driving electroosmotic force. This force will be numerically similar to the net driving Starling force in small pores, but distinctly different in large pores. From previous data on the hydrostatic and colloid osmotic forces, the fixed charge density at the two interfaces of 1) the glomerular and 2) the peritubular capillary membrane were calculated and used to predict the flux of a series of charged protein probes. The close fit to the experimental data in both the capillary beds is in line with the gel concept presented. The gel concept (but hardly a rigid membrane) explains the ability of capillary membranes to alter their permeability in response to external forces. Gel membranes can furthermore be predicted to have a self-rinsing ability, as entrapped proteins will increase the local fixed charge density, leading to fluid entry into the region between the particle and the pore rim, which by consequent widening of the channel will facilitate extrusion of trapped proteins.

Dependence of Electrical Conductivity on Fixed Charge Density in Articular Cartilage

1983 ◽  
Vol &NA; (177) ◽  
pp. 283???288 ◽  
Author(s):  
ISAO HASEGAWA ◽  
SHINYA KURIKI ◽  
SHIGEO MATSUNO ◽  
GORO MATSUMOTO
Keyword(s):  
Electrical Conductivity ◽  
Articular Cartilage ◽  
Charge Density ◽  
Fixed Charge ◽  
Fixed Charge Density
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