Preparation and photodynamic bactericidal effects of curcumin-β-cyclodextrin complex

摘要

To overcome the poor water solubility of curcumin, a curcumin-ll-cyclodextrin (Cur-ll-CD) complex was prepared as a novel photosensitizer. Fourier-transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) were used to verify the formation of Cur-ll-CD. Furthermore, the ROS generation capacity and photodynamic bactericidal effect were measured to confirm this Cur-ll-CD complex kept photodynamic activity of curcumin. The result showed Cur-ll-CD could effectively generate ROS upon blue-light irradiation. The plate count assay demonstrated Cur-ll-CD complex possess desirable photodynamic antibacterial effect against food-borne pathogens including Staphylococcus aureus, Listeria monocytogenes and Escherichia coli. The cell morphology determined by scanning electron microscope (SEM) and transmission electron microscope (TEM) showed Cur-ll-CD could cause cell deformation, surface collapse and cell structure damage of the bacteria, resulting in the leakage of cytoplasmic; while agarose gel electrophoresis and SDS-PAGE further illustrated the inactivation mechanisms by Cur-ll-CD involve bacterial DNA damage and protein degradation.