Development and evaluation of a non-peptidic ligand for the molecular imaging of inflammatory processes using S100A9 (MRP14) as a novel target

The establishment of novel molecular imaging tools to monitor the local activity of inflammation remains an interdisciplinary challenge. Our target, the alarmin S100A9, one subunit of the heterodimer S100A8/S100A9 (calprotectin), is locally secreted in high concentrations from immigrated and activated phagocytes at local sites of inflammation. Calprotectin is already a well established serum biomarker for many inflammatory disorders. Here we show the development and first evaluation of the novel S100A9 specific molecular imaging probe Cy5.5-CES271 for optical imaging of local inflammatory activity in vivo.