Multifunctional Eu3+ /Gd3+ dual-doped calcium phosphate vesicle-like nanospheres for sustained drug release and imaging

• Published in: Biomaterials 2012-09, Vol.33 (27), p.6447-6455
• Main Authors: Chen, Feng, Huang, Peng, Zhu, Ying-Jie, Wu, Jin, Cui, Da-Xiang
• Format: Article
• Language: English
• Subjects: Advanced Basic Science; Animals; Bio-imaging; Calcium phosphate; Calcium Phosphates - chemistry; Cell Death - drug effects; Cell Line, Tumor; Delayed-Action Preparations - pharmacology; Dentistry; Diagnostic Imaging - methods; Drug delivery; Drug delivery systems; Drugs; Europium - chemistry; Gadolinium - chemistry; Humans; Imaging; Luminescent Measurements; Magnetic Resonance Imaging; Mice; Mice, Nude; Multifunctional; Nanosphere; Nanospheres; Nanospheres - ultrastructure; Nanostructure; Nitrogen - chemistry; Photoluminescence; Spectrophotometry, Infrared; Surface Properties; Temperature; Thermogravimetry; Unilamellar Liposomes; X-Ray Diffraction
• ISSN: 0142-9612; 1878-5905
• DOI: 10.1016/j.biomaterials.2012.05.059

Abstract A facile room-temperature solution method is reported for the preparation of multifunctional Eu3+ and Gd3+ dual-doped calcium phosphate (CaP) (Eu3+ /Gd3+ −CaP) vesicle-like nanospheres in the presence of an amphiphilic block copolymer polylactide–block–monomethoxy(polyethyleneglycol) (PLA−mPEG). The photoluminescent (PL) and magnetic multifunctions of CaP vesicle-like nanospheres are realized by dual-doping with Eu3+ /Gd3+ ions. Under the excitation at 393 nm, Eu3+ /Gd3+ −CaP vesicle-like nanospheres exhibit a strong near-infrared (NIR) emission at 700 nm, and the PL intensity can be adjusted by varying Eu3+ and Gd3+ concentrations. Furthermore, Eu3+ /Gd3+ −CaP vesicle-like nanospheres can be used as the drug nanocarrier and have a high drug loading capacity and ultralong sustained drug release using ibuprofen as a model drug. The drug release from the drug delivery system of Eu3+ /Gd3+ −CaP vesicle-like nanospheres can sustain for a very long period of time (more than 80 days). The as-prepared Eu3+ /Gd3+ −CaP vesicle-like nanospheres exhibit essentially inappreciable toxicity to the cells in vitro . The noninvasive visualization of nude mice with subcutaneous injection indicates that the Eu3+ /Gd3+ −CaP vesicle-like nanospheres are suitable for in vivo bio-imaging. In vivo imaging tests using the subcutaneous injection model of nude mice indicate that Eu3+ /Gd3+ −CaP vesicle-like nanospheres can be used as an imaging agent for the NIR luminescence imaging. Thus, the Eu3+ /Gd3+ −CaP vesicle-like nanospheres are promising for applications in the biomedical fields such as multifunctional drug delivery systems and tissue engineering scaffolds with bio-imaging guidance.