The effect of substrate stiffness on fibrillin expression by mouse embryonic fibroblasts (MEFs)

Open Access
Author:
Sheldrake, Anne E
Area of Honors:
Bioengineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Justin Lee Brown, Thesis Supervisor
  • Peter J Butler, Honors Advisor
  • William O Hancock, Faculty Reader
Keywords:
  • MEFs
  • tissue engineering
  • cardiac
  • acrylamide
  • bisacrylamide
  • heart
  • fibrillin
  • scar tissue
Abstract:
Heart disease is the number one cause of death in the United States. During a cardiac infarction, the coronary arteries are occluded, preventing blood flow to the heart. Without blood flow, the myocardium does not receive sufficient oxygen to maintain cell health. If cardiomyoctes die, the myocardium is unable to be regenerated. Most strategies for dealing with a myocardial infarction focus on reducing the necrosis. A method must be developed to repair the damage to cardiac tissue and the use of a cardiac patch is promising. If correctly designed, the scaffold of a cardiac patch could deliver healthy cardiac cells to the myocardium and provide structural support for the cells until they can produce their own extracellular matrix. A scaffold of the optimum stiffness would direct the differentiation of cells into healthy cardiac tissue. To determine the optimum stiffness for a cardiac patch, substrates with stiffness’s of of 5, 11, and 20 kPa were prepared from acrylamide/bisacrylamide solutions. The relative concentration of fibrillin-1, a major component of scar tissue, produced by mouse embryonic fibroblasts (MEFs) cultured on the scaffolds was observed by fluorescent microscopy, Western blot, and a slot blot. In qualitative and quantitative comparisons, the 11 kPa gels were shown to have the highest level of fibrillin expression. The fibrillin levels were lower on 20 kPa gels. To manufacture a patch with a stiffness in the physiological range of cardiac tissue, a 20 kPa gel may provide the best compromise between mechanics and fibrillin expression.