Multifunctional Gd,Ce,Tb co-doped β-tricalcium phosphate porous nanospheres for sustained drug release and bioimaging.

Multifunctional Gd,Ce,Tb co-doped β-tricalcium phosphate (TCP) porous nanospheres are prepared by a facile solvothermal strategy with trimethyl phosphate as the phosphorus source. The as-prepared nanomaterial (average diameter of 100 nm) has a multiple level pore size distribution with the specific surface area of 124.33 m2 g-1, which benefits drug loading. Its photoluminescent and magnetic multifunctions are realized by the co-doping of Gd3+, Ce3+ and Tb3+ ions, which make the nanomaterial promising for both fluorescence and magnetic resonance imaging techniques. Furthermore, the nanomaterial exhibits excellent cytocompatibility and a relatively high doxorubicin loading capacity as well as sustained pH-sensitive drug release behaviour. It is suggested that the Gd,Ce,Tb co-doped β-TCP porous nanospheres are promising for applications in the biomedical fields such as multifunctional drug delivery systems and tissue engineering scaffolds with bioimaging guidance.