Properties of extracellular matrix-like scaffolds for the growth and differentiation of endothelial progenitor cells.

Background: To provide a new strategy for constructing small vascular graft, the survival conditions of endothelial progenitor cells (EPCs), which were seeded on two different groups of extracellular matrix (ECM) scaffolds were studied in vitro.

Materials And Methods: The scaffold was made with a mixture of fibrinogen, fibronectin, and laminin, which solidified to form unpressed structure. A 1N force could make it to be pressed. EPCs induced from cultures of rat mesenchymal stem cells were seeded on two different groups of ECM scaffolds: (1) pressed scaffolds; and (2) unpressed scaffolds. The survival conditions of cells on the two groups of scaffolds were reflected by properties below: cell attachment and proliferation detected by cell counting; differentiation of EPCs detected by changes in the cell morphology and the expression of endothelial marker von Willebrand factor (VWF) using immunofluorescence, immuno-blot, and real-time PCR; the two different scaffolds were characterized for their surface ultra-structures by SEM, and torques by a rheometer.

Results: The cells grew faster on the pressed scaffold (P<0.001) for the first 7 d. Furthermore, cells on the pressed scaffolds displayed more uniform shapes with morphology resembling that of endothelial cells than those on the unpressed scaffolds. VWF protein expressions were also higher in cells from the pressed scaffold. Real-time PCR showed correlated changes too. In addition, the pressed scaffold with EPCs showed the smallest torque value among all scaffolds (P<0.01).

Conclusion: Pressed ECM-like scaffold promoted the survival condition of EPC. It may be used to promote endothelialization within the next generation of vascular grafts in vivo.