Theranostics 2013; 3(3):210-222. doi:10.7150/thno.5298

Research Paper

Phase and Size Controllable Synthesis of NaYbF4 Nanocrystals in Oleic Acid/ Ionic Liquid Two-Phase System for Targeted Fluorescent Imaging of Gastric Cancer

Liyuan Pan1, Meng He1, Jiebing Ma1, Wei Tang2, Guo Gao1, Rong He1✉, Haichuan Su3✉, Daxiang Cui1✉

1. Department of Bio-Nano Science and Engineering, Key Laboratory for Thin Film and Microfabrication of Ministry of Education, Institute of Micro-Nano Science and Technology, Shanghai Jiao Tong University, 800Dongchuan Road, Shanghai200240, P. R. China;
2. Key laboratory for Ultrafine Materials of ministry of Education, Engineering Research Center for Biomedical material of Ministry of Education, East China University of Science and Technology, Shanghai, 200237, P. R. China;
3. Department of Oncology, Tangdu Hospital, Fourth Military Medical University, 8Xinsi Road, Xi'an 71008, P. R. China.

Abstract

Upconversion nanocrystals with small size and strong fluorescent signals own great potential in applications such as biomolecule-labeling, in vivo tracking and molecular imaging. Herein we reported that NaYbF4: 25%Gd, 2%Tm upconversion nanocrystals with small size and strong fluorescent signals were controllably synthesized by oleic acid (OA)/ ionic liquid (IL) two-phase system for targeted fluorescent imaging of gastric cancer in vivo. The optimal synthesis condition of NaYbF4: 25%Gd, 2%Tm upconversion nanocrystals by OA/IL two-phase system was established, adding more metal ion such as Na+ ion could facilitate the size control and crystal-phase transition, more importantly, markedly enhancing fluorescent intensity of beta-phase nanocrystals compared with traditional methods. Alpha-phase NaYbF4, 2%Tm upconversion nanocrystals with less than 10nm in diameter and beta-phase NaYbF4: 25%Gd, 2%Tm upconversion nanocrystals with 30 nm or so in diameter and strong fluorescent signals were obtained, these synthesized nanocrystals exhibited very low cytotoxicity. Folic acid-conjugated silica-modified beta-phase NaYbF4: 25%Gd, 2%Tm upconversion nanocrystals were prepared, could actively target gastric cancer tissues implanted into nude mice in vivo, and realized targeted fluorescent imaging. Folic acid-conjugated silica-modified NaYbF4: 25%Gd, 2%Tm upconversion nanocrystals show great potential in applications such as targeted near infared radiation fluorescent imaging, magnetic resonance imaging and targeted therapy of gastric cancer in the near future.

Keywords: NaYbF4: 25%Gd, 2%Tm upconversion nanocrystals, synthesis, targeted imaging, fluorescent imaging, gastric cancer, cytotoxicity.

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How to cite this article:
Pan L, He M, Ma J, Tang W, Gao G, He R, Su H, Cui D. Phase and Size Controllable Synthesis of NaYbF4 Nanocrystals in Oleic Acid/ Ionic Liquid Two-Phase System for Targeted Fluorescent Imaging of Gastric Cancer. Theranostics 2013; 3(3):210-222. doi:10.7150/thno.5298. Available from http://www.thno.org/v03p0210.htm