The enzymatic degradation of scaffolds and their replacement by vascularized extracellular matrix in the murine myocardium

Biomaterials. 2006 Apr;27(10):2247-57. doi: 10.1016/j.biomaterials.2005.11.002. Epub 2005 Nov 28.


Replacement of injured myocardium by cell-based degradable scaffolds is a novel approach to regenerate myocardium. Understanding the foreign body reaction (FBR) induced by the scaffold is requisite to predict unwanted site effects or implant failure. We evaluated the FBR against a biodegradable scaffold applied on injured myocardium in mice. Cryolesions and collagen type I scaffolds (Col-I) were applied to the left ventricle of mice. Cell infiltration, neovascularization, collagen deposition, matrix metalloproteinase (MMP-8) expression, enzymatic activity and scaffold degradation were determined at different time points (2-70 days). Infiltration of mainly macrophages, neutrophils and blood vessels was completed within 14 days. High numbers of neutrophils accumulated around the Col-I fibers and degradation of Col-I fibers into small fragments was observed on day 14. Active MMP-8 co-localized with the neutrophils on day 14, indicating enzymatic degradation of Col-I by neutrophil collagenase. Highly vascularized extracellular matrix remained at day 70. No differences were observed in the FBR to Col-I after application on healthy or injured myocardium. The FBR had no adverse effects on the adjacent myocardial tissue. In conclusion, cardiac scaffolds are degraded by MMP-8 and replaced by vascularized extracellular matrix during the FBR on injured myocardium.

Publication types

  • Evaluation Study

MeSH terms

  • Animals
  • Collagen Type I / immunology
  • Collagen Type I / metabolism
  • Collagen Type I / ultrastructure
  • Extracellular Matrix / chemistry
  • Extracellular Matrix / metabolism*
  • Foreign-Body Reaction
  • Macrophages / cytology
  • Macrophages / immunology
  • Male
  • Matrix Metalloproteinase 8 / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Myocardium / chemistry*
  • Myocardium / metabolism
  • Myocardium / pathology
  • Neovascularization, Physiologic
  • Neutrophils / cytology
  • Neutrophils / immunology
  • Polyethylene Terephthalates / metabolism
  • Regeneration*
  • Tissue Engineering / methods*


  • Collagen Type I
  • Polyethylene Terephthalates
  • Matrix Metalloproteinase 8