Figure 7.

Sustained MSC Multipotentcy and in vivo Efficacy at Late Passages. (A) To verify that the MSCs retain multipotency at later passages (p11 and beyond), cells were stimulated to undergo tri-lineage differentiation and were evaluated. Adipogenesis and Chondrogenesis scale bars = 200 μm; Osteogenesis scale bar = 50 μm. (B) FACS histograms of p12 mMSCs grown in hypoxia+bFGF show that cells retain MSC specific surface marker expression and are positive for CD44, Sca1 and are negative for CD34, CD45, CD13, and CD31. At higher passages, however, cells have lost CD90.2 surface expression. (C) To test if late passage murine MSCs can promote and rescue neovascularization in a murine model of hindlimb ischemia, mMSCs (p11) were encapsulated in alginate and delivered to the ischemic hind limb (IL) by subcutaneous implantation. Laser Doppler perfusion imaging was performed at day 14 on animals that received either empty capsules or encapsulated mMSCs. Representative heat maps are presented to indicate perfusion levels. Perfusion levels were quantified for n = 3 animals per group and presented as a ratio of the perfusion level in the ischemic limb (IL) to the contralateral control non-ischemic limb (NIL). n = 3; *p = 0.02 vs. empty; data presented as mean ± S.E.M.