Natural flavonoid glycoside-based self-assembled nanoparticles for synergistic antibacterial activity and improved antioxidant properties

Nanotechnology can enhance bacterial inhibition. Some of the available drug delivery systems with inorganic or organic carriers might be toxic and difficult to transform clinically. Therefore, simple, non-toxic antibiotics with excellent bacterial inhibition ability need to be synthesized. In this study, a carrier-free drug delivery system was constructed by self-assembling baicalin, extracted from Scutellaria baicalensis, and palmatine, extracted from Fibraurea recisa Pierre. The synthesis of the nanoparticles was confirmed using a combination of characterization methods, such as X-ray single-crystal diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR), and field emission scanning electron microscopy (SEM). The in vitro antibacterial tests revealed that the minimum inhibitory concentration (MIC) of the nanoparticles was 0.05 mu mol/mL, which was significantly lower than that of both monomers. The cumulative dissolution of baicalin was improve from 30 % to 70 % in 4 h after the Self-assembly preparation process. Moreover, due to the rapid release of baicalin and palmatine, the nanoparticles show immediately oxygen free radical scavenging ability. In vitro cytotoxicity and hemolysis tests also revealed that the obtained self-assembled nanoparticles of baicalin and palmatine had satisfactory biocompatibility. Even when the concentration of BA-PA NPs was 0.8 mu M (2 x MIC), the viability of the DU145 cells was greater than 90 % and the hemolysis rate of nanoparticles was less than 5 %. This supramolecular self-assembly strategy for using flavonoid glycosides from traditional herbal medicine might be a new approach to combat bacterial infections.