VNPs as Tools for Nanomedicine - Viral Nanoparticles: Tools for Materials Science and Biomedicine - page 218

were captured approximately 1 h after injection. (d) Cryosection of an 11.5-day
mouse embryo perfused with CPMV-A555. White box indicates the region magnified
in (g). Scale bar, 1.1 mm. (e) Yolk sac vasculature, magnified. Scale bar, 25 μm. (f)
Capillaries in the head region. Scale bar, 25 μm. (g) Intersomitic and placental vessels
in embryo tissue section. Scale bar, 100 μm. (h-o) Comparison of intravital imaging
with CPMV-A555 (h-k) and fluorescent nanospheres (e-o) in E11.5 mouse embryo.
(h, l) Whole embryo. Scale bar, 1.1 mm. (i, m) Head region, arrows indicate areas
of differential staining of anterior vasculature, brain vasculature. Scale bar, 770 μm.
(j, n) CPMV staining allows increased resolution of intersomitic vessels. Scale bar,
540 μm. (k, o) Arrows indicate capillary and larger vessels of yolk sac membrane.
Scale bar, 50 μm. Reproduced Lewis, J. D., Destito, G., Zijlstra, A., Gonzalez, M. J.,
Quigley, J. P., Manchester, M., and Stuhlmann, H. (2006) Viral nanoparticles as tools
for intravital vascular imaging, Nat. Med. , 12 (3), 354-360.

(Lewis ., 2006). Fluorescent-labeled CPMV particles were injected

intravenously in chick and mouse embryos, and imaging was performed over
a time frame of 72 h. CPMV was internalized by endothelial cells and could be
detected lining the vasculature, thus allowing high-resolution imaging. Major
blood vessels as well as microvasculature could be visualized to a depth of up
to 500

et al

µ

m. Such high specificity and resolution could not be achieved when
using fluorescent-labeled nanospheres, which are a current state-of-the-art
imaging platform used in optical imaging (Fig. 8.5) (Lewis

et al ., 2006).

Figure 8.5 Comparison of intravital vascular staining intensity over time in the chick

embryo. Comparative analysis of changes in vascular staining intensity over time in
the chick embryo using fluorescent-labeled (CPMV) particles or

0.04 μm nanospheres. Representative images captured immediately after injection
(time = 0) and 4 h after injection (time = 4 h) showing sampled regions of interest
(ROI) during intravital retained fluorescence assay. Fluorescence average of negative
ROI (−) was subtracted from positive ROI (+). Reproduced from Lewis, J. D., Destito,
G., Zijlstra, A., Gonzalez, M. J., Quigley, J. P., Manchester, M., and Stuhlmann, H.
(2006) Viral nanoparticles as tools for intravital vascular imaging,

Cowpea mosaic virus

Nat. Med. , 12 (3),

354-360.