Self-Assembly Loading of Schisandra chinensis Nanoparticles and Its Effect on the Malignant Biological Behavior of Ovarian Cancer Cells

Schisandra polysaccharide (SCHP) was utilized as the target drug, and Zein (corn prolamine) was utilized as the drug carrier. First, SCHP/Zein nanoparticles (Zein-SCHP NPs) were prepared. Then, a polydopamine (PDP) coating was utilized to enhance the stability and tumor targeting of Zein. Finally, the folic acid (FA)-targeting ligand was covalently attached to the PDP-modified Zein-SCHP@PDP NP surface to form a highly pH-sensitive NP (Zein-SCHP@PDP-FA NPs) with active/passive targeting. In the experiment, apart from physical characterization of Zein-SCHP-based nanomaterials, the in vitro cytotoxicity and cell uptake properties of these materials were tested. In addition, an ovarian cancer cell line, SKOV3, was taken as the research object to explore the photodynamic-mediated killing effect of Zein-SCHP@PDP-FA NPs on this cancer cell. The results demonstrated that the average particle size of Zein-SCHP@PDP-FA NPs was (379.68±1.36) nm, the zeta potential was (−43.68±1.67) mV, the encapsulation efficiency was (97.86±1.38)%, and the drug loading was (11.75±0.16)%. Transmission electron microscope (TEM) suggested that the Zein-SCHP@PDP-FA NPs were spherical, and there was no adhesion between the particles. Differential scanning calorimetry (DSC) and far infrared (FIR) results indicated that SCHP existed in the NPs in the crystal structure and proved that the PDP and FA were successfully modified. The in vitro release of the drug showed that Zein-SCHP@PDP-FA NPs had sustained release, and the CCK-8 test showed that Zein-SCHP@PDP-FA NPs were highly cytotoxic and could notably reduce the IC 50 values of SCHP. Furthermore, in vitro uptake experiments revealed that Zein-SCHP@PDP-FA NPs exhibited strong specific recognition in cells expressing different folate receptors. Compared with Zein-SCHP NPs and Zein-SCHP@PDP NPs, Zein-SCHP@PDP-FA NPs combined with photodynamic therapy enhanced reactive oxygen species (ROS) production in cells, downregulated hypoxia-inducible factor (HIF)-1 α and interleukin (IL)-6 proteins, and exerted more destructive effects on SKOV3 cells.