Introduction
Researchers are placing much efforts on the nanocomposites with physiochemical properties. Graphene quantum dots (GQDs) have attracted remarkable interest in drug delivery and biosensing attributed to their tunable photoluminescence and great biocompatibility1. Moreover, inverse spinel cobalt ferrite (CoFe2O4) is gaining significant attention due to its moderate saturation magnetization and great chemical-stability2. The CoFe2O4 nanoparticles present promising potential in biomedical application, especially in targeted drug delivery that can alleviate the side effects of conventional chemotherapy by reducing the systemic distribution of drugs. However, there are no reports of GQDs/CoFe2O4 based nanocomposites for targeted drug delivery and fluorescence imaging of cancer cells.
Methods
In this work, we fabricated the novel GQD/CoFe2O4@SiO2-FA nanoparticles and investigated their potential application as the fluorescence nanoprobe for the tumor-targeted drug delivery. GQDs were synthesized by the carbonization of citric acid (CA). The CoFe2O4 were synthesized via thermodecomposition. The surface modification of CoFe2O4 nanoparticles with silica and amine group enabled the covalent bonding with GQDs. Then the attached FA led to the tumor-targeted delivery and intracellular release of anticancer drug DOX in Hela cells (Fig.1).
Results and discussion
We show that the resulting CoFe2O4 nanoparticles possessed an average size of 15.3±1.7 nm (Fig.2a). The spherical GQDs with the average size of 3 nm exhibited blue fluorescence under 365nm UV light and no fluorescence in bright filed compared with blank solvent (Fig.2b-2d), indicating the rendered blue fluorescence property of the fabricated GQDs. The drug loading capacity onto GQD/CoFe2O4@SiO2-FA was explored. The qualitative and quantitative analyses of cellular drug release in vitro and the fluorescence imaging of living Hela cells were performed. The biocompatibility of fabricated GQD/CoFe2O4@SiO2 nanoparticles was confirmed with cytotoxicity assessment.
Conclusion
We fabricated the fluorescence GQD/CoFe2O4@SiO2-FA nanoparticles and explored the potential application for targeted drug delivery and fluorescence imaging of cancer cells. These GQD@CoFe2O4 based nanocomposite could be a promising platform for cancer therapy, leading to further developments of intelligent anticancer drug carrier.
Reference
1. Y. Li et. al, Adv. Mater. 23, 776-780 (2011).
2. Urs. Häfeli et. al, Springer, (2013).
