Hollow Au loaded with kanamycin for pharmacological and laser-triggered photothermal sterilization

Abstract

Effective and appropriate use of existing antibiotics is imperative because of the problem of antibiotic resistance. Driven by this need, a platform of hollow Au loaded with kanamycin (hAu-kana) was produced. This platform has the ability to target drug delivery and facilitate photothermal sterilization. Hollow Au was synthesized by galvanic replacement reaction. We then covalently attached anti-E. coli to hollow Au modified with the ligands SH-PEG and L-cysteine. SH-PEG prevents the aggregation of AuNPs, and the carboxyl group of the L-cysteine further links with IgG. The dual-ligand hollow Au can be targeted to deliver the drug after modification with the anti-E. coli, thus improving the sterilization efficiency. This was followed by loading the model drug kanamycin (hAuNPs-anti-E. coli-kana) to facilitate photothermal treatment. The bactericidal effect on the bacterial strain was investigated by incubating E. coli with the hybrid and eventually subjecting it to laser irradiation (650 nm, 200 mW cm⁻², diameter 2 mm, 40 min). Compared with E. coli treated with hAuNPs-anti-E. coli-kana alone, irradiation of E. coli treated with hAuNPs-anti-E. coli-kana with laser has obvious synergistic effect and made the sterilization more effective. Taken together, this hybrid suggests a new method for achieving synergistic bactericidal effect.