Figure 4. Bone formation at 12 wks. (a) Photomicrograph of an H & E-stained section from a co-transplant sample retrieved at 12 wks. Micro-CT analyses of (b) bone mineral density from bone marrow stromal cell transplants (BMSC) and bone marrow stromal cell, endothelial cell co-transplants (BMSC/EC). (c) Total bone volume fraction in BMSC transplants and co-transplants of BMSC and EC. An additional experimental group of scaffolds alone with no cells (PLGA) was included at this time-point. A scale bar is shown in (a). Values represent mean ± standard error of the mean. *Statistically significant difference (p < 0.05), as compared with BMSC condition (n = 6).