Abstract 12016: An Enhanced Collagen-Based Matrix Promotes Cardiomyocytic Differentiation of Embryonic Stem Cells
Background: Previous studies have incorporated the oligosaccharide sialyl LewisX (sLeX) into an injectable collagen matrix for regeneration of ischemic muscle. It was hypothesized that this material may support differentiation of progenitors towards a cardiac lineage. This study sought to characterize its elastic and hydropolar properties that are conducive towards myogenesis, and its potential for generating cardiomyocytes.
Methods: Elastic moduli and water contact angles (WCA) of matrices were measured. Mouse embryonic bodies were cultured on: 1) collagen matrix; or, 2) sLeX-collagen matrix; and compared to 3) tissue culture plastic substrate (TCPS) controls. After 15 days, cells were harvested and analyzed for cardiac markers using immunofluorescence, qPCR and Western blotting.
Results: Collagen matrices did not produce a detectable WCA, but incorporation of sLeX reliably produced regions with WCA of <48°, indicative of the presence of hydrophobic and hydrophilic domains. The elastic modulus of the two matrices did not differ (P=0.9); values ranged from 9.0-19.9kPa, which supports maximal myogenic differentiation. L-Selectin, the receptor for sLeX, was expressed in cells from days 0 to 15, indicating potential interaction with the sLeX-collagen matrix. Spontaneously beating cells were observed on all substrates. At day 15, cells on both collagen and sLeX-collagen matrices had greater expression of cardiac myogenesis markers GATA4 (1.8-fold; P<0.002) and α-cardiac actin (3.11-fold; P<0.04), compared to cells on TCPS. Only the sLeX-matrix culture induced increased transcription of cardiac markers Nkx2.5 (2.3-fold; P=0.009) and atrial natriuretic factor (3.1-fold; P=0.02) in cells, compared to TCPS. Immunofluorescence demonstrated a greater presence of cardiac α-actinin on the sLeX-collagen matrix.
Conclusions: These results demonstrate that the physical properties of the sLeX-collagen matrix are optimal for myogenesis. In addition to having regenerative effects in vivo, these injectable materials may be useful for generating functional cardiomyocytes for transplantation, without the need for genetic or viral manipulation.
- Regenerative medicine stem cells
- Stem/progenitor cells
- Tissue engineering
- Cardiac regeneration
- Extracellular matrix
- © 2011 by American Heart Association, Inc.