Fig. 5
Imaging of locally activated paGFP in murine deep femoral marrow reveals high positioning stability of the LIMB implant. a paGFP mice were implanted with a LIMB microendoscope (n = 3 mice). After 35 days, the mice were injected intravenously with Qdots to label the vasculature. Photoactivation of paGFP was performed at a wavelength of 840 nm in a 75 × 75 × 30 µm3 square area in the center of the field of view. Additional injections of Qdots were given before each recording. We performed the described photoactivation experiments repeatedly, up to three times in the same animal at day 27, 35, and 56 post-surgery, during homeostasis with similar results. Blood vessels which could be observed over the whole period of 36 h are indicated by arrowheads, whereas those that appear or disappear within this time period are labeled by asterisks. Scale bar = 30 µm. b Similarly to a, photoactivation of a 150 × 150 × 9 µm3 region within the 500 × 500 × 66 µm3 field of view in a paGFP mouse with a permanent calvarial imaging window let us easily identify the photoactivated area. The paGFP fluorescence could be visualized over several imaging sessions. Scale bar = 100 µm. During these time windows we observed changes of the vasculature in both, the deep femoral marrow and bone marrow islets of the calvarium
