Synthesis, purification, and anticancer effect of magnetic Fe3O4-loaded poly (lactic-co-glycolic) nanoparticles of the natural drug tetrandrine.

Here, we have successfully synthesised and purified multifunctional PLGA-based nanoparticles by the co-encapsulation of an anticancer drug (tetrandrine) and a magnetic material (Fe3O4). The obtained Tet-Fe3O4-PLGA NPs had a uniform spherical shape with a particle size of approximately 199 nm and a negative surface charge of -18.0 mV, displaying a high encapsulation efficiency. Furthermore, TEM studies provided representative images of the purification process of the magnetic nanoparticles with MACS® technology. The MFM and VSM results indicated that both the Fe3O4 NPs and Tet-Fe3O4-PLGA NPs were superparamagnetic. The DSC spectrum demonstrated that Tet was successfully encapsulated within the PLGA-based nanoparticles. Significantly, the release studies revealed NPs had a relatively slower release rate than free Tet after 8 h's initial burst release, which had decreased from 98% to 65% after 24 h. In vitro cellular studies revealed that NPs could effectively penetrate into A549 cells and A549 multicellular spheroids to exert cytotoxicity, displaying a significantly high anti-proliferation effect. Moreover, western blot demonstrated that the co-loaded NPs had a higher anticancer activity by injuring lysosomes to activate the mitochondria pathway and induce A549 cell apoptosis. The magnetic characteristics and high anticancer activity support the use of Tet/Fe3O4 co-loaded PLGA-based nanoparticles as a promising strategy in the treatment of lung cancer.