TITLE:
A Spectrophotometric Analysis of Human Osteoarthritic Cartilage Explants Subjected to Specific Capacitively Coupled Electric Fields
AUTHORS:
Carl T. Brighton, Wei Wang, Charles C. Clark, Amy Praestgaard
KEYWORDS:
Osteoarthritis; Cartilage Explants; Capacitive Coupling; Spectrophotometry; Disease Modification
JOURNAL NAME:
Open Journal of Biophysics,
Vol.3 No.2,
April
30,
2013
ABSTRACT: We have previously shown that capacitively coupled
electrical stimulation of either normal bovine articular chondrocytes or
osteoarthritic human articular cartilage explants resulted in up-regulation of
cartilage matrix gene expression and down-regulation of metalloproteinase gene
expression. In addition, collagen and proteoglycan protein levels were also
elevated. To determine visually the effect of specific electric fields on
modifying cartilage structure, freshly harvested human full-thickness
osteoarthritic cartilage explants were stimulated in the absence or presence of
interleukin-1β, an inflammatory
cytokine, and were examined photographically and spectrophotometrically.
Hexosamine and hydroxyproline contents were also determined. Spectrophotometric
analysis was used to quantify any changes in the depth of defects in the
cartilage ranging from surface level (red-colored) to the deepest affected
layer (blue-colored). Interleukin-1β treatment alone caused significant additional cartilage erosion. Electrical
stimulation alone resulted in significant decreases in the cartilage defects. Electrical
stimulation in the presence of interleukin-1β resulted in a small, but significant, surface improvement. Meta-analysis also
confirmed a significant increase in the hexosamine and hydroxyproline contents
(indicating matrix deposition). It was concluded that an appropriate electric
field could modify osteoarthritic lesions in full-thickness cartilage plugs by
increasing matrix production and/or by decreasing matrix destruction.
Furthermore, it appears that spectrophotometric analysis is a relatively easy
method for quantifying the “filling in” or healing of articular cartilage
defects.