title: Europium-doped amorphous calcium phosphate porous nanospheres: preparation and application as luminescent drug carriers.
abstract: Calcium phosphate is the most important inorganic constituent of biological tissues, and synthetic calcium phosphate has been widely used as biomaterials. In this study, a facile method has been developed for the fabrication of amorphous calcium phosphate (ACP)/polylactide-block-monomethoxy(polyethyleneglycol) hybrid nanoparticles and ACP porous nanospheres. Europium-doping is performed to enable photoluminescence (PL) function of ACP porous nanospheres. A high specific surface area of the europium-doped ACP (Eu3+:ACP) porous nanospheres is achieved (126.7 m2/g). PL properties of Eu3+:ACP porous nanospheres are investigated, and the most intense peak at 612 nm is observed at 5 mol% Eu3+ doping. In vitro cytotoxicity experiments indicate that the as-prepared Eu3+:ACP porous nanospheres are biocompatible. In vitro drug release experiments indicate that the ibuprofen-loaded Eu3+:ACP porous nanospheres show a slow and sustained drug release in simulated body fluid. We have found that the cumulative amount of released drug has a linear relationship with the natural logarithm of release time (ln(t)). The Eu3+:ACP porous nanospheres are bioactive, and can transform to hydroxyapatite during drug release. The PL properties of drug-loaded nanocarriers before and after drug release are also investigated.
authors.affiliation: State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P, R, China. y.j.zhu@mail.sic.ac.cn.
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.forename: Ying-Jie
authors.initials: YJ
authors.lastname: Zhu
authors.forename: Kui-Hua
authors.initials: KH
authors.lastname: Zhang
authors.forename: Jin
authors.initials: J
authors.lastname: Wu
authors.forename: Ke-Wei
authors.initials: KW
authors.lastname: Wang
authors.forename: Qi-Li
authors.initials: QL
authors.lastname: Tang
authors.forename: Xiu-Mei
authors.initials: XM
authors.lastname: Mo