Properties and characterization of pH responsive nanoparticles based on polysaccharides from Bletilla striata as carriers in cancer therapy

In the present work, a new drug delivery system was designed with polysaccharides from Bletilla striata (BSP) as a capping agent for the pH responsive release of anticancer drugs. First, BSP-ZnO nanoparticles (NPs) prepared and characterized by field emission scanning electron microscopy (FESEM), dynamic light scattering (DLS), ultraviolet (UV) spectrophotometer, and Fourier transform infrared (FTIR). Second, resveratrol (RES) was loaded into the BSP-ZnO NPs, and its release properties were studied at pH 5.0 and 7.4. Interestingly, the stability study of RES-BSP-ZnO NPs showed that RES-BSP-ZnO NPs were very stable in blood circulation (pH 7.4) and accumulated and released RES under acidic conditions. Finally, the potential anticancer activity of the RES-BSP-ZnO NPs on Caco-2 cells was evaluated by anticancer activity and intracellular ROS level. The results demonstrated that the new drug delivery system not only met our expectations for the pH response release of RES, but also exhibited synergistic anticancer properties in vitro. From above all, the experiments indicated that BSP-ZnO NPs had great potential for pH responsive drug delivery in cancer therapy.