Fluorescent Pluronic nanodots for in vivo two-photon imaging.
We report the synthesis of new nanosized fluorescent probes based on bio-compatible polyethylene-polypropylene glycol (Pluronic) materials. In aqueous solution, mini-emulsification of Pluronic with a high fluorescent di-stryl benzene-modified derivative, exhibiting a two-photon absorption cross section as high as 2500 Goeppert-Mayer units at 800 nm, leads to nanoparticles exhibiting a hydrodynamic radius below 100 nm. We have demonstrated that these new probes with luminescence located in the spectral region of interest for bio-imaging (the yellow part of the visible spectrum) allow deep (500 microm) bio-imaging of the mice brain vasculature. The dose injected during our experiments is ten times lower when compared to the classical commercial rhodamine-B isothicyanate-Dextran system but gives similar results to homogeneous blood plasma staining. The mean fluorescent signal intensity stayed constant during more than 1 h.
Maurin
Mathieu
M
Laboratoire de Spectrométrie Physique, UMR 5588, Saint Martin d'Hères, France.
Vurth
Laeticia
L
Vial
Jean-Claude
JC
Baldeck
Patrice
P
Marder
Seth R
SR
Van der Sanden
Boudewijn
B
Stephan
Olivier
O
D000818:Animals; D001921:Brain / Q000098:blood supply; D003911:Dextrans / Q000737:chemistry; D003952:Diagnostic Imaging / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry*; D007668:Kidney / Q000098:blood supply; D008099:Liver / Q000098:blood supply; D051379:Mice; D008807:Mice, Inbred BALB C; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D020442:Poloxamer / Q000737:chemistry*; D015203:Reproducibility of Results; D012235:Rhodamines / Q000737:chemistry; D013500:Surface Tension
D003911:Dextrans; D005456:Fluorescent Dyes; D012235:Rhodamines; C051311:rhodamine dextran; D020442:Poloxamer