A novel model for the pre-clinical imaging of inflamed human synovial vasculature

Objective. The purpose of this study was to explore the development of a pre-clinical nuclear imaging model as a tool for testing novel radiopharmaceutical agents for imaging and/or delivery systems to human tissues. Here we report for the first time the imaging of human synovial tissue transplanted into SCID mice using a radiolabelled anti-E-selectin antibody and NanoSPECT/CT technology. Methods. Human synovium was transplanted into SCID mice. Two to three weeks post-transplantation tissue vasculature was stimulated with TNF-alpha by intra-graft injection 5 h prior to intravenous injection of In-111-labelled anti-E-selectin or isotype control antibody. At 1, 4, 24 and 48 h animals were imaged and transplant activity quantified. Results. Activity was detectable in the grafts at all time points, with clear delineation of the transplants in the reconstructed images. A significant difference in graft radioactivity was observed at 4 and 24 h with a significantly higher uptake (P < 0.05) of In-111-anti-E-selectin compared with isotype control antibody. Conclusions. This article highlights NanoSPECT/CT imaging in the SCID mouse chimeric model as a powerful tool for the pre-clinical development of radiopharmaceutical and delivery agents targeting human synovial tissue in vivo.