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- Qian, Jun, et al.
(author)
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Photosensitizer encapsulated organically modified silica nanoparticles for direct two-photon photodynamic therapy and In Vivo functional imaging
- 2012
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In: Biomaterials. - : Elsevier BV. - 0142-9612 .- 1878-5905. ; 33:19, s. 4851-4860
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Journal article (peer-reviewed)abstract
- Nanoparticle-assisted two-photon imaging and near infrared (NIR) imaging are two important technologies in biophotonics research. In the present paper, organically modified silica (ORMOSIL) nanoparticles encapsulated with either PpIX (protoporphyrin IX) photosensitizers or IR-820 NIR fluorophores were synthesized and optically characterized. Using the former ORMOSIL nanoparticles, we showed: (i) direct excitation of the fluorescence of PpIX through its efficient two-photon absorption in the intracellular environment of tumor cells, and (ii) cytotoxicity towards tumor cells by PpIX under two-photon irradiation. The latter ORMOSIL nanoparticles can be used as efficient NIR fluorescent contrast agents for various types . in vivo animal imaging. We applied IR-820 doped ORMOSIL nanoparticles in . in vivo brain imaging of mice. We also demonstrated the applications of them to sentinel lymph node (SLN) mapping of mice. Finally, we showed that the nanoprobes could target the subcutaneously xenografted tumor of a mouse for long time observations. ORMOSIL nanoparticles have great potentials for disease diagnosis and clinical therapies.
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| 4. |
- Liu, Wen, et al.
(author)
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Fluorescence resonance energy transfer (FRET) based nanoparticles composed of AIE luminogens and NIR dyes with enhanced three-photon near-infrared emission for in vivo brain angiography
- 2018
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In: Nanoscale. - : ROYAL SOC CHEMISTRY. - 2040-3364 .- 2040-3372. ; 10:21, s. 10025-10032
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Journal article (peer-reviewed)abstract
- Near-infrared (NIR) fluorescence is very important for high-contrast biological imaging of high-scattering tissues such as brain tissue. Unfortunately, commercial NIR dyes are excited usually by visible light, and their multi-photon absorption (MPA) cross-sections are small. Here, we design new co-encapsulated NIR nanoparticles (NPs) with a large three-photon (3PA) absorption cross-section. A form of aggregation-induced emission (AIE) luminogen (AIEgen), 2,3-bis(4-(diphenylamino)-[1,1-biphenyl]-4-yl) fumaronitrile (TPATCN), is introduced as the donor, and a form of NIR dye, silicon 2,3-naphthalocyanine bis-(trihexylsilyloxide) (NIR775), is adopted as the acceptor. Under the excitation of a 1550 nm fs laser, TPATCN-NIR775 NPs demonstrated a bright three-photon fluorescence centered at 785 nm. The energy transfer efficiency of the TPATCN-NIR775 NPs was calculated to be as high as 90%, which could be attributed to the good spectral overlap between the emission of TPATCN and the absorption of NIR775. By injection with TPATCN-NIR775 NPs, a vivid 3D reconstruction of mouse brain vasculature was obtained with even small blood vessels clearly visualized. The design strategy used for the co-encapsulated AIE-NIR NPs would be helpful in synthesizing more NIR probes for deep-tissue biological imaging in the future.
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