Design of biocompatible Fe3O4@MPDA mesoporous core-shell nanospheres for drug delivery

The magnetically core-shell Fe3O4@mesoporous polydopamine (Fe3O4@MPDA) nanospheres were prepared by a facile and efficient self-assembly approach, the key mechanism for generating the mesoporous structure of PDA is the π-π stacking interactions between dopamine molecules and 1,3,5-trimethylbenzene (TMB) molecules. Because of the mesoporous structure of the surface, the Fe3O4@MPDA particles exhibited a large specific surface area of 17.27 m2/g and total pore volumes of 0.057 cm3/g. Besides, it maintained good magnetic properties. The adsorption properties and mechanism of organic dyes methylene blue (MB) and rhodamine B (RhB) on Fe3O4@MPDA nanoparticles were studied. And a model anticancer drug of doxorubicin hydrochloride (DOX) was used as a target drug to research the delivery and sustained-release properties of the Fe3O4@MPDA particles. The average loading capacities toward DOX could reach 295.2 mg/g, and the release amounts were about 41% within 60 h. Meanwhile, the in vitro cytotoxicity of the DOX loaded Fe3O4@MPDA nanoparticles against hela cells and osteoblast cells were also being researched. The DOX-loaded Fe3O4@MPDA nanoparticles showed greater toxicity than Fe3O4 nanoparticles and Fe3O4@MPDA nanoparticles, even than free DOX. Compared with osteoblasts, the inhibitory effect on hella cells was more obvious. The above properties are of great significance for its application in the field of biological medicine, especially the target drug carriers.