FIG. 4.

Improved acute passage through the pulmonary microcirculation of bioreactor MSCs following intravenous injection. A significant 10-fold increase in the concentration of arterial MSCs was observed with bioreactor-expanded cells compared with the monolayer MSCs expanded in parallel following intravenous delivery in rats (*p<0.01). The fluorescent cell concentration was determined by flow cytometry analysis of the blood after lysis of erythrocytes. Green fluorescent cells were isolated by plating from bioreactor MSCs injected rat arterial blood, but not from the monolayer MSCs experiments (inset). Scale bar, 100 μm. Color images available online at www.liebertpub.com/tec