HMNPs@PDA-GQDs-FA as carries of gambogic acid for inhibiting VX2 tumor cells

Ellipsoidal hollow magnetic nanoparticles (HMNPs) were first synthesized through a hydrothermal method and coated with SiO2 via the Stöber method, followed by template hydrothermal synthesis using C18TMS/TEOS volume ratio for silica-shell formation. Then, the core–shell structure was grafted with graphene quantum dots (GQDs), dopamine hydrochloride (PDA), and folic acid (FA) by amide reaction to obtain HMNPs@PDA-GQDs-FA. Transmission electron microscopy, X-ray photoelectron spectroscopy, fluorescence spectroscopy, and N2 adsorption/desorption analysis confirmed the successful construction of the HMNPs@PDA-GQDs-FA nanoscale carrier–cargo composite. The carrier HMNPs@PDA-GQDs-FA had improved loading (51.63 %) and higher release (47.18 %) of gambogic acid (GA) at an acidic pH (5.7) than the release (32.23 %) at an acidic pH (7.4), showing the pH response of PDA to the surrounding environment of tumor cells. Cytotoxicity test results showed that the cell survival rate was above 95 %, indicating that the carrier–cargo had low cytotoxicity. Cell lethality was greatly improved after loading GA, and the advantages of using FA-grafted HMNPs as a targeting ligand for tumor imaging were demonstrated by SPECT imaging analysis. These results showed that HMNPs@PDA-GQDs-FA had good biocompatibility and could be used for the treatment of VX2 tumors after loading GA. [Display omitted] •As-prepared HMNPs@PDA-GQDs-FA has high loading and cumulative release of GA.•GQDs have low cytotoxicity and good biocompatibility, which was used for imaging.•FA and Fe3O4 can target tumor cells, which improve the treatment effect and PDA encapsulation improves drug loading rate.•HMNPs@PDA-GQDs-FA has a pH dependence on the releasing of GA.•The release kinetics and mechanism of HMNPs@PDA-GQDs-FA to GA were studied.