Fig. 1

MSCTRAIL show time- and amount-dependent sensitivity to ⁸⁹Zr-oxine labelling but retain MSC phenotype. MSCTRAIL cells were labelled from frozen with ⁸⁹Zr-oxine between 79 and 332 kBq/10⁶. Cells show reduced proliferation with increasing amount as indicated by metabolism of ATP (a) and NADH (b). Error bars show standard deviation (SD). *p < 0.05, **p < 0.01, ***p < 0.001 2-way ANOVA with Dunnett’s multiple comparisons test vs PBS control. c Retention of ⁸⁹Zr oxine decreases over time (n = 4). The 2-way ANOVA analysis showed that the majority of variation (67.5%) was due to time (p < 0.0001), with amount having a significant (p = 0.015) but small effect (3% of variation) on activity retention. d MSCTRAIL retain their MSC phenotype (CD45-ve, CD73, CD90, and CD105+ve), post-radiolabelling with ⁸⁹Zr-oxine (amount shown 332 kBq/10⁶ cells)