| 1. |
- Li, Nana, et al.
(författare)
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Yb3+-enhanced UCNP@SiO2 nanocomposites for consecutive imaging, photothermal-controlled drug delivery and cancer therapy
- 2016
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Ingår i: Optical Materials Express. - : Optical Society of America. - 2159-3930 .- 2159-3930. ; 6:4, s. 1161-1171
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Tidskriftsartikel (refereegranskat)abstract
- UCNP-based drug delivery systems commonly rely on stimulisensitive auxiliaries, lacking a straightforward manipulation strategy. Here we designed Yb3+-enhanced upconversion/ mesoporous silica nanocomposites (UCNP@SiO2) for consecutive cell imaging, photothermal drug delivery and cancer therapy. Core UCNPs (NaYbF4: 2% Er3+) were synthesized and coated with mesoporous silica, whose high-efficiency photothermal properties were verified in vitro. Then doxorubicin hydrochloride (DOX) was loaded on the UCNP@SiO2 and successfully triggered to release by a 975 nm laser of 150 mW or 300 mW. Before the therapy, we used a much lower laser power of 15 mW (which would cause little DOX release) for UCNP-probed fluorescence imaging of Hela cells and affirmed a favorable cell uptake of nanocomposites. Subsequently, cell viability assay and PI stain have demonstrated that the 300 mW laser could manipulate drug delivery of UCNP@SiO2-DOX and cause a severe loss of cell viability. The Yb3+-enhanced UCNP@SiO2 shows a great potential in simultaneous biomedical imaging and photothermal-triggered on-site drug delivery for chemotherapy of cancer. (C) 2016 Optical Society of America
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| 2. |
- Wen, Xuanyuan, et al.
(författare)
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Designed Er3+-singly doped NaYF4 with double excitation bands for simultaneous deep macroscopic and microscopic upconverting bioimaging
- 2016
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Ingår i: Biomedical Optics Express. - : OSA - The Optical Society. - 2156-7085. ; 7:6, s. 2174-2185
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Tidskriftsartikel (refereegranskat)abstract
- Simultaneous deep macroscopic imaging and microscopic imaging is in urgent demand, but is challenging to achieve experimentally due to the lack of proper fluorescent probes. Herein, we have designed and successfully synthesized simplex Er3+-doped upconversion nanoparticles (UCNPs) with double excitation bands for simultaneous deep macroscopic and microscopic imaging. The material structure and the excitation wavelength of Er3+-singly doped UCNPs were further optimized to enhance the upconversion emission efficiency. After optimization, we found that NaYF4:30% Er3+@NaYF4:2% Er3+ could simultaneously achieve efficient two-photon excitation (2PE) macroscopic tissue imaging and three-photon excitation (3PE) deep microscopic when excited by 808 nm continuous wave (CW) and 1480 nm CW lasers, respectively. In vitro cell imaging and in vivo imaging have also been implemented to demonstrate the feasibility and potential of the proposed simplex Er3+-doped UCNPs as bioprobe.
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| 3. |
- Wu, Ruitao, et al.
(författare)
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Optical depletion mechanism of upconverting luminescence and its potential for multi-photon STED-like microscopy
- 2015
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Ingår i: Optics Express. - : Optical Society of America. - 1094-4087. ; 23:25, s. 32401-32412
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Tidskriftsartikel (refereegranskat)abstract
- Simulated emission depletion (STED) microscopy is very powerful, but still suffers from small tissue penetration depth, photobleaching of fluorescent probes and complicated imaging systems. Here, we propose an optical luminescence depletion mechanism employing upconverting nanoparticles (UCNPs) and explore its potential for multi-photon STED-like microscopy. With the addition of Yb3+ ions in NaYF4:Er3+ UCNPs, the two-photon green emission of Er3+ under 795-nm excitation was successfully depleted by 1140-nm laser through the synergetic effect of the excited state absorption and the interionic energy transfer. This STED-like depletion mechanism was systematically investigated using steady-state rate equations, evidenced by the surprising emerging of 478-nm emission. The green emission depletion efficiency was about 30%, limited by the current laser source. Our work indicates that NaYF4:Yb3+/Er3+ UCNPs will be potential probes for multi-photon super-resolution microscopy with many advantages, including long-wavelength-induced large penetration, non-photobleaching and non-photoblinking properties, cost-effective and simplified imaging systems.
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| 4. |
- Zhan, Qiuqiang, et al.
(författare)
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Controlling the excitation of upconverting luminescence for biomedical theranostics : neodymium sensitizing
- 2016
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Ingår i: Optical Materials Express. - : Optical Society of America. - 2159-3930 .- 2159-3930. ; 6:4, s. 1011-1023
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Tidskriftsartikel (refereegranskat)abstract
- With the rapid development of nanotechnology over the past decade, lanthanide doped upconverting nanoparticles (UCNPs) have been successfully synthesized and have emerged as an important class of nanomaterials. In contrast to the traditional Yb3+-sensitized UCNPs, the emerging Nd3+-sensitized UCNPs have many merits in controlling the excitation of upconverting luminescence, including minimizing overheating effect, increasing the imaging depth and so on. In this review paper, we provide a comprehensive survey of the most recent advances in developing Nd3+-sensitized UCNPs, which include nanocomposition, mechanisms, and some typical nanostructures of Nd3+-sensitized UCNPs. Furthermore, an important emphasis is placed on various applications including downconversion and upconversion photoluminescence for bioimaging, high-resolution, and deep tissue imaging and tumor diagnosis and therapy. Potential challenges and prospective development are also discussed. (C) 2016 Optical Society of America
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