High Harvest Yield, High Expansion, and Phenotype Stability of CD146 Mesenchymal Stromal Cells from Whole Primitive Human Umbilical Cord Tissue
Figure 2
Tissue processing and method of isolation affect total cell yield and population phenotype. (a) Physical properties of the UC tissue provide an estimate that 10-11 million cells per gram can be isolated from the tissue (also see Table 1 and Table 1 in Supplementary Material available online at doi:10.1155/2009/789526). (b) The theoretical yield of 10-11 million cells/UC gram includes 79% vascular cells, 9% perivascular cells, and 12% WJ cells. Distinct phenotypes based on enzymatic method are evident by both morphology (c) and molecular phenotype (d)–(f). (c) Cell area or spreading in 2D monolayer is significantly larger for dispase-isolated cells versus collagenase-isolated cells (mean ± s.e.m., ), although the cells have similar diameter or size when measured prior to surface adhesion. (d) Mean surface marker expression on day 0 of isolation. Collagenase-isolated cell populations have a significantly higher level of expression of CD44 (P = .005), CD105 (P = .014), and CD90 (P < .001), as compared to dispase-isolated cells that exhibit a significantly higher level of endothelial marker expression, CD34 (P < .001), CD144 (P < .001), and CD146 (P = .049), and CD73 (P < .001) which was also detected in the endothelium. (e) Marker expression at week 1 postisolation. Significant differences were detected for expression of CD45 (P = .01), CD34 (P < .001), CD144 (P = .006), and CD90 (P = .003). (f) Marker expression at week 3 postisolation. Significant differences were detected for expression of CD144 (P = .017), CD146 (P = .008), and CD90 (P = .001). The use of collagenase enzyme yields a cell population with significantly higher MSC marker expression levels in comparison to both dispase enzyme digestion and mechanical dissociation.The latter two methods, however, yield populations with significantly higher endothelial cell marker expression levels than the collagenase enzyme digest.
