Upconversion nanophosphors for small-animal imaging.
Rare-earth upconversion nanophosphors (UCNPs), when excited by continuous-wave near-infrared light, exhibit a unique narrow photoluminescence with higher energy. Such special upconversion luminescence makes UCNPs promising as bioimaging probes with attractive features, such as no auto-fluorescence from biological samples and a large penetration depth. As a result, UCNPs have emerged as novel imaging agents for small animals. In this critical review, recent reports regarding the synthesis of water-soluble UCNPs and their surface modification and bioconjugation chemistry are summarized. The applications of UCNPs for small-animal imaging, including tumor-targeted imaging, lymphatic imaging, vascular imaging and cell tracking are reviewed in detail. The exploration of UCNPs as multifunctional nanoscale carriers for integrated imaging and therapy is also presented. The biodistribution and toxicology of UCNPs are further described. Finally, we discuss the challenges and opportunities in the development of UCNP-based nanoplatforms for small-animal imaging (276 references).
Department of Chemistry & Institutes of Biomedical Sciences, Fudan University, Shanghai 200433, PR China.
Jing
J
Zhou
Zhuang
Z
Liu
Fuyou
F
Li
D000818:Animals; D002460:Cell Line; D006801:Humans; D028581:Lanthanoid Series Elements / Q000737:chemistry; D049408:Luminescent Agents / Q000009:adverse effects / Q000737:chemistry* / Q000378:metabolism / Q000627:therapeutic use; D008163:Luminescent Measurements; D057054:Molecular Imaging / Q000379:methods*; D015335:Molecular Probes / Q000009:adverse effects / Q000737:chemistry / Q000378:metabolism / Q000627:therapeutic use; D049329:Nanostructures / Q000009:adverse effects / Q000737:chemistry* / Q000627:therapeutic use
D028581:Lanthanoid Series Elements; D049408:Luminescent Agents; D015335:Molecular Probes