Molecular transport in collagenous tissues measured by gel electrophoresis.
Molecular transport in tissues is important for drug delivery, nutrient supply, waste removal, cell signaling, and detecting tissue degeneration. Therefore, the objective of this study was to investigate gel electrophoresis as a simple method to measure molecular transport in collagenous tissues. The electrophoretic mobility of charged molecules in tissue samples was measured from relative differences in the velocity of a cationic dye passing through an agarose gel in the absence and presence of a tissue section embedded within the gel. Differences in electrophoretic mobility were measured for the transport of a molecule through different tissues and tissue anisotropy, or the transport of different sized molecules through the same tissue. Tissue samples included tendon and fibrocartilage from the proximal (tensile) and distal (compressive) regions of the bovine flexor tendon, respectively, and bovine articular cartilage. The measured electrophoretic mobility was greatest in the compressive region of the tendon (fibrocartilage), followed by the tensile region of tendon, and lowest in articular cartilage, reflecting differences in the composition and organization of the tissues. The anisotropy of tendon was measured by greater electrophoretic mobility parallel compared with perpendicular to the predominate collagen fiber orientation. Electrophoretic mobility also decreased with increased molecular size, as expected. Therefore, the results of this study suggest that gel electrophoresis may be a useful method to measure differences in molecular transport within various tissues, including the effects of tissue type, tissue anisotropy, and molecular size.
Department of Aerospace and Mechanical Engineering, Bioengineering Graduate Program, University of Notre Dame, Notre Dame, IN 46556, USA.
Michael D
MD
Hunckler
Department of Aerospace and Mechanical Engineering, Bioengineering Graduate Program, University of Notre Dame, Notre Dame, IN 46556, USA.
Jennifer M R
JMR
Tilley
Department of Aerospace and Mechanical Engineering, Bioengineering Graduate Program, University of Notre Dame, Notre Dame, IN 46556, USA. Electronic address: rroeder@nd.edu.
Ryan K
RK
Roeder
D000818:Animals; D016880:Anisotropy; D001692:Biological Transport; D002417:Cattle; D003094:Collagen / Q000737:chemistry* / Q000502:physiology; D004587:Electrophoresis, Agar Gel; D051445:Fibrocartilage / Q000737:chemistry; D008954:Models, Biological; D010619:Phenazines / Q000737:chemistry; D011509:Proteoglycans / Q000737:chemistry; D011754:Pyronine / Q000737:chemistry; D013710:Tendons / Q000737:chemistry / Q000502:physiology
D010619:Phenazines; D011509:Proteoglycans; D003094:Collagen; D011754:Pyronine; C009195:safranine T
Anisotropy; Cartilage; Fibrocartilage; Gel electrophoresis; Molecular transport; Permeability; Tendon