Dual-targeting magnetic fluorescent mesoporous organosilicon hollow nanospheres for gambogic acid loading, sustained release and anti-tumor properties

Hydrophilic mesoporous organosilica nanoparticles (HMNPs) were synthesized by introducing Fe 3 O 4 on the basis of mesoporous organosilicon nanoparticle hollow spheres as a drug carrier. N- and S- doped graphene quantum dots (NS-GQDs) and polyethylenimine (PEI) were grafted onto the surface of HMNPs. Finally, two types of composite mesoporous particles, HMNPs-NS-GQDs-PEI-HA and HMNPs-NS-GQDs-PEI-FA which can enter VX2 cells for fluorescence confocal imaging, were further modified by targeting ligand hyaluronic acid (HA) and folic acid (FA). The heteroatoms of NS-GQDs have intelligent functional effects, which can not only improve the photoluminescence performance of GQDs, but also generate conjugated quantum dots with GA, so as to synergistically improve the drug effectiveness. Under illumination by near-infrared (NIR) radiation, gambogic acid (GA)-loaded HMNPs was promoted to the sustained release of gambogic acid. The loading and sustained release of the anticancer drug GA on the compound mesoporous particles were studied. The cytotoxicity and antitumor properties of the compound mesoporous particles were investigated by both in vitro cell experiments and in vivo experiments in mice. The results showed that HMNPs-NS-GQDs-PEI-HA and HMNPs-NS-GQDs-PEI-FA have desired fluorescence and magnetic properties for cell fluorescence imaging and magnetic targeting of cancer cells. Both of composite mesoporous particles have desired loading capacity on GA and pH-responsive drug release behavior as well as low cytotoxicity and good biocompatibility. The cell survival rate of HMNPs-NS-GQDs-PEI-HA and HMNPs-NS-GQDs-PEI-FA loaded with GA was only 7.69% and 8.71%, respectively, after 24 h, which can effectively induce the apoptosis of VX2 cells. Tumor experiments in mice demonstrated that HMNPs-NS-GQDs-PEI-HA inhibits tumor growth and exhibits magnetic targeting function.