Layer-by-layer deposition of luminescent polymeric microgel films on magnetic Fe3O4@SiO2 nanospheres for loading and release of ibuprofen

This work demonstrates a simple and feasible method to construct magnetic and luminescence nanospheres for drug delivery. Fe3O4@SiO2 core–shell structure nanospheres were firstly prepared, the matrix films capable of loading and release of anionic molecules were then successfully deposited on the surface of the Fe3O4@SiO2 nanospheres via a layer-by-layer (LbL) assembly method by using luminescence microgels (named FITC-PAHD) and chondroitin sulfate (CS) as building blocks and verified by ultraviolet visible and photoluminescence measurements, transmission electron microscopy and fluorescence microscopy. The model drug ibuprofen was loaded into the Fe3O4@SiO2@(FITC-PAHD/CS)4 nanospheres because of the electrostatic interaction of ibuprofen with amine groups in the FITC-PAHD microgels via ion exchange. Ibuprofen loaded in the nanospheres can be released in 0.9% normal saline in a sustainable way for 12 days and the Fe3O4@SiO2@(FITC-PAHD/CS)4 nanospheres have a maximum uptake amount of ibuprofen of 117 mg·g− 1. The magnetic and luminescence nanospheres with high loading capacity are expected to be widely useful as carriers for drug delivery followed by magnetic separation and luminescent detection.