FIG. 2.

Optical imaging of implanted osteogenic constructs (circled in red) in a mouse with corresponding histologic analysis confirming mineralization. The mice were injected 1 week (a, b) and 1 month (c, d) post-implantation with 800CW BT and evaluated 24 h later with NIR optical imaging. White light images (a, c) indicate location of differentiated and control implantation sites. NIR images taken at the same time points (b, d) indicate binding and labeling of osteogenic tissue constructs with 800CW BT reflected in higher signal intensities for these regions compared to the surrounding tissue. Following optical imaging, magnetic resonance microscopy (MRM) of the osteogenic constructs confirmed the presence of the tissue (e). Following in vivo imaging, the osteogenic construct was excised and cut in 5-μm sections for microscopy of adjacent von Kossa (f) and NIR microscopy (g). Additional histological analysis included hematoxylin and eosin staining of slides at 40× magnification (h).