In vivo time-gated fluorescence imaging with biodegradable luminescent porous silicon nanoparticles.
Fluorescence imaging is one of the most versatile and widely used visualization methods in biomedical research. However, tissue autofluorescence is a major obstacle confounding interpretation of in vivo fluorescence images. The unusually long emission lifetime (5-13 μs) of photoluminescent porous silicon nanoparticles can allow the time-gated imaging of tissues in vivo, completely eliminating shorter-lived (<10 ns) emission signals from organic chromophores or tissue autofluorescence. Here using a conventional animal imaging system not optimized for such long-lived excited states, we demonstrate improvement of signal to background contrast ratio by >50-fold in vitro and by >20-fold in vivo when imaging porous silicon nanoparticles. Time-gated imaging of porous silicon nanoparticles accumulated in a human ovarian cancer xenograft following intravenous injection is demonstrated in a live mouse. The potential for multiplexing of images in the time domain by using separate porous silicon nanoparticles engineered with different excited state lifetimes is discussed.
Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, USA.
Luo
L
Gu
David J
DJ
Hall
Zhengtao
Z
Qin
Emily
E
Anglin
Jinmyoung
J
Joo
David J
DJ
Mooney
Stephen B
SB
Howell
Michael J
MJ
Sailor
D000818:Animals; D005260:Female; D006801:Humans; D049408:Luminescent Agents / Q000737:chemistry; D051379:Mice; D053758:Nanoparticles / Q000737:chemistry*; D009368:Neoplasm Transplantation; D061848:Optical Imaging / Q000379:methods*; D010051:Ovarian Neoplasms; D012825:Silicon / Q000737:chemistry; D023041:Xenograft Model Antitumor Assays
D049408:Luminescent Agents; D012825:Silicon