Isotonic biaxial loading of fibroblast-populated collagen gels: a versatile, low-cost system for the study of mechanobiology.
We developed a simple, versatile system for applying a range of biaxial loads to cell-matrix constructs for the study of mechanobiology. The system consists of porous polyethylene bars that are polymerized into a square fibroblast-populated gel and loaded by freely hanging weights attached to sutures routed through a custom loading rig. The cost to manufacture each mold/loading rig pair was less than US dollars 250 and the expected life of the components is up to 10 years. Neonatal and adult cardiac fibroblasts contracted gels to a decreasing extent as external load was increased ( P=0.003) and achieved contraction forces of up to 1.4 mN per million cells. Strain distributions were reasonably homogeneous in the central region of the gel (25% of gel area), but clearly nonhomogeneous outside that central region. The primary advantages of this system are simplicity, low cost, biaxial loading, and the ability to test for a dose-response effect of mechanical load. The current disadvantages are the inability to apply cycling loading and the inhomogeneities introduced by the use of rigid loading bars.
Department of Biomedical Engineering, Columbia University, 1210 Amsterdam Ave, New York, NY 10027, USA.
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V
Knezevic
A J
AJ
Sim
T K
TK
Borg
J W
JW
Holmes
D000818:Animals; D000831:Animals, Newborn; D016880:Anisotropy; D018929:Cell Culture Techniques / Q000191:economics / Q000295:instrumentation* / Q000379:methods; D002478:Cells, Cultured; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005347:Fibroblasts / Q000502:physiology*; D005782:Gels; D006321:Heart / Q000502:physiology; D008567:Membranes, Artificial; D010812:Physical Stimulation / Q000295:instrumentation* / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014481:United States; D016474:Weight-Bearing / Q000502:physiology*
D005782:Gels; D008567:Membranes, Artificial