Effects of blank (no SDF-1) and SDF-1 loaded microspheres on cultured primary CPCs. In the presence of SDF-1 loaded microspheres (MS), over 2-fold more CPCs were adherent to fi bronectin within 1 hour of exposure ( A ; n = 4); B , C are representative images of adherent CPCs in the presence of blank or SDF-1 loaded microspheres, respectively. More CPCs migrated towards SDF-1 microspheres ( D ; n = 4); E , F are representative images of blank and SDF-1 loaded microsphere-induced migration of CPCs, respectively. The effect of SDF-1 on CPC migration was mainly chemotactic, rather than chemokinetic, as evidenced by the greater migratory effect of CPCs towards SDF-1 when it is presented as a gradient (G) . Scale bars = 100 μ m. * p < 0.05; ** p < 0.05 vs . all others.