Programmed biomolecule delivery to enable and direct cell migration for connective tissue repair

Nat Commun. 2017 Nov 24;8(1):1780. doi: 10.1038/s41467-017-01955-w.

Abstract

Dense connective tissue injuries have limited repair, due to the paucity of cells at the wound site. We hypothesize that decreasing the density of the local extracellular matrix (ECM) in conjunction with releasing chemoattractive signals increases cellularity and tissue formation after injury. Using the knee meniscus as a model system, we query interstitial cell migration in the context of migratory barriers using a novel tissue Boyden chamber and show that a gradient of platelet-derived growth factor-AB (PDGF-AB) expedites migration through native tissue. To implement these signals in situ, we develop nanofibrous scaffolds with distinct fiber fractions that sequentially release active collagenase (to increase ECM porosity) and PDGF-AB (to attract endogenous cells) in a localized and coordinated manner. We show that, when placed into a meniscal defect, the controlled release of collagenase and PDGF-AB increases cellularity at the interface and within the scaffold, as well as integration with the surrounding tissue.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Cattle
  • Cell Movement*
  • Cells, Cultured
  • Collagenases / metabolism*
  • Connective Tissue Cells / cytology*
  • Connective Tissue Cells / metabolism
  • Extracellular Matrix / chemistry
  • Extracellular Matrix / metabolism
  • Male
  • Meniscus / injuries
  • Meniscus / metabolism
  • Meniscus / physiopathology*
  • Platelet-Derived Growth Factor / metabolism*
  • Rats
  • Regeneration
  • Tissue Engineering
  • Tissue Scaffolds / chemistry

Substances

  • Platelet-Derived Growth Factor
  • platelet-derived growth factor AB
  • Collagenases