Nanotechnology enabled biomedical fluorescence imaging in the second near-infrared window
Abstract/Contents
- Abstract
- Fluorescence imaging in the second near-infrared window (NIR-II, 1.0-1.7 microns) has many salient advantages over the visible (400-750 nm) and the traditional near-infrared (NIR-I, 750-900 nm) windows owing to the reduced photon scattering and negligible tissue autofluorescence. However, NIR-II fluorescence imaging has been limited by the scarcity of materials with sufficient NIR-II fluorescence quantum efficiency, and single-walled carbon nanotube (SWNT) had been the only fluorophore for biological imaging in the NIR-II window. This work aims to enhance the intrinsic NIR-II fluorescence of SWNTs, apply SWNTs for in vivo imaging of real-world medical problems in animal models and develop new NIR-II fluorophores other than SWNTs. First, a plasmonic gold substrate is used to enhance the intrinsically low NIR-II fluorescence of SWNTs and to improve the sensitivity of cancer cell imaging using SWNTs as molecular targeting probes. The sensitive distance dependence of fluorescence enhancement of SWNTs is then exploited to probe the trans-membrane motion of single nanotube molecules and reveal the internalization pathway as receptor-mediated endocytosis. The biocompatible SWNTs are further applied to an in vivo animal model of lower limb ischemia, where we demonstrate microvascular imaging and hemodynamic measurement using NIR-II fluorescence, with improved spatial resolution over X-ray computer tomography (CT) and broader dynamic range of blood flowmetry than ultrasound. In a rationally chosen sub-region of NIR-II in the 1.3-1.4 micron range, chemically separated SWNTs allow for non-invasive brain vascular imaging through intact scalp and skull with sub-10 micron resolution at millimeter depth of penetration. Lastly, two new materials, Ag2S quantum dots (QDs) and conjugated copolymers are developed to expand the toolbox of NIR-II fluorophores. The Ag2S QDs afford in vitro targeted cancer cell imaging and in vivo mouse imaging with high tumor uptake. The high fluorescence quantum yield of the conjugated copolymer allows for ultrafast dynamic NIR-II imaging of the arterial blood flow with waveform cardiac cycles revealed in hemodynamic analysis. The many benefits of NIR-II fluorescence imaging demonstrated in this work based on the development of a handful of biocompatible NIR-II nanomaterials bode well for future biological research and clinical applications with this new imaging technique.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2014 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Hong, Guosong |
|---|---|
| Primary advisor | Dai, Hongjie, 1966- |
| Thesis advisor | Dai, Hongjie, 1966- |
| Thesis advisor | Cui, Bianxiao |
| Thesis advisor | Fayer, Michael D |
| Advisor | Cui, Bianxiao |
| Advisor | Fayer, Michael D |
| Associated with | Stanford University, Department of Chemistry. |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Guosong Hong. |
|---|---|
| Note | Submitted to the Department of Chemistry. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2014. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2014 by Guosong Hong
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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