Infrared‐Mediated Drug Elution Activity of Gold Nanorod‐Grafted TiO₂ Nanotubes

Abstract

The purpose of this research was to prepare gold nanorod‐ (GNR‐) grafted TiO 2 nanotubes by thiolactic acid treatment and evaluate remote‐controlled drug elution and antibacterial activity by infrared (IR) light irradiation. Tetracycline used as an antibiotic was loaded into GNR‐grafted TiO 2 nanotubes by using 2 w/v% polylactic acid solutions. A near‐IR laser (830 nm) was used for remote‐controlled IR light irradiation. Results of SEM, TEM, XRD, and EDX revealed that GNR chemically bonded to the whole surface of the TiO 2 nanotubes. An antibiotic release test revealed that on‐off drug elution was triggered effectively by the photothermal effect of GNR grafted on TiO 2 nanotubes. Furthermore, an antibacterial agar zone test indicated that the annihilated zone of Streptococcus mutans in the experimental group with IR light irradiation was significantly larger than that of the corresponding group without IR light irradiation ( P < 0.05). Therefore, GNR‐grafted TiO 2 nanotubes would be expected to extend the limited usage of TiO 2 , which show photocatalytic activity only within the ultraviolet (UV) to IR region, thereby allowing the development of novel fusion technologies in the field of implant materials.