Core鈥揝hell Structured Up-Conversion Luminescent and Mesoporous NaYF4:Yb3+/Er3+@nSiO2@mSiO2 Nanospheres as Carriers for Drug Deliver

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• 作者：Xiaojiao Kang ; Ziyong Cheng ; Chunxia Li ; Dongmei Yang ; Mengmeng Shang ; Ping鈥檃n Ma ; Guogang Li ; Nian Liu ; Jun Lin
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：August 18, 2011
• 年：2011
• 卷：115
• 期：32
• 页码：15801-15811
• 全文大小：1291K
• 年卷期：v.115,no.32(August 18, 2011)
• ISSN：1932-7455

文摘

Core鈥搒hell structured up-conversion luminescent and mesoporous NaYF₄:Yb³⁺/Er³⁺@nSiO₂@mSiO₂ nanospheres were prepared by coating mesoporous SiO₂ layers with different thicknesses on NaYF₄:Yb³⁺/Er³⁺ nanoparticles via a simple two-step sol鈥揼el process. The obtained sample shows a typical mesoporous structure and well-dispersed spherical morphology with a narrow size distribution. The nanospheres exhibit little cytotoxicity (via MTT assay), and ibuprofen (IBU) was used as a model drug to access the release properties of the system in detail. The amount of IBU adsorbed in mesoporous channels increases with the thickness of the ordered mesoporous silica shell coated on the NaYF₄:Yb³⁺/Er³⁺ nanoparticles. The in vitro release study of IBU reveals a release profile in two steps: an initial diffusion-controlled release, followed by a slower release rate. Furthermore, upon excitation by a 980 nm near-infrared laser, the nanospheres emit green (²H_11/2 and ⁴S_3/2 鈫?⁴I_15/2) and red (⁴F_9/2 鈫?⁴I_15/2) fluorescence of Er³⁺ even after the loading of IBU. Interestingly, the emission intensity of Er³⁺ in the bifunctional (mesoporous and luminescence) drug carrier increases with an increase of the cumulative released amount of the model drug (IBU). Thus, the extent of drug release can be easily identified, tracked, and monitored based on the change of the up-conversion luminescence. These results suggest that the core鈥搒hell structured NaYF₄:Yb³⁺/Er³⁺@nSiO₂@mSiO₂ nanospheres are a promising material for controlled drug release.