Gold nanorod-covered kanamycin-loaded hollow SiO2 (HSKAurod) nanocapsules for drug delivery and photothermal therapy on bacteria

Abstract

A hybrid bactericidal material, gold nanorod-covered kanamycin-loaded hollow SiO₂ (HSKAu_rod) nanocapsules, is constructed. The hybrid material combines the features of a chemical drug with photothermal physical sterilization which decreases the dosage of broad-spectrum antibiotic and the physical damage of biological systems. Hollow SiO₂ nanocapsules are used as carriers for drug delivery. The nanocapsules load a model drug, kanamycin, and are covered with gold nanorods to avoid drug leakage and realize photothermal treatment. The sterilizing effect on the bacterial strain is investigated by incubating E. coli BL21 with the hybrid nanocapsules and irradiating under near-infrared light (NIR) for 20 min. A bactericidal effect, i.e., a sterilizing rate of 53.47%, is achieved for the HSKAu_rod nanocapsules under NIR irradiation, with respect to a net sum sterilizing rate of 34.49% for the individual components of the HSKAu_rod nanocapsules, e.g., carrier nanocapsules, chemical sterilization of kanamycin and physical sterilization due to the gold nanorods under NIR irradiation. It is demonstrated that the combination of chemical drug and physical sterilization results in an obvious synergistic effect and makes the sterilization more effective. This novel hybrid has great potential as an adjuvant therapeutic alternative material for sterilization or even for the control of disease.