Fig. 2

Characterization of human cytokines in peripheral blood of mice carrying different states of genetically engineered stromal cell-laden scaffolds. a Schematic of creating different human cytokine producing local microenvironments beneath the skin in an immunodeficient NSG mouse and a gross image of scaffolds after 4 weeks implantation. b, c Detection of (b) hSDF1a and (c) hVEGFa in mouse blood serum post 6-week implantation (N = 3–5, *P < 0.05). A low level hSDF1a caused by cross-reactivity with mouse SDF1a was subtracted from the data. Systemic level hSDF1a and hVEGFa were detected in genetically engineered growing mBMSC scaffolds bearing mice but not hTNFa. Systemic level availability of hSDF1a and hVEGFa were significantly increased by co-seeding with hBMSC or dramatically decreased by arresting their growth