Surface-Adaptive Gold-Based Nanoplatform for Low-Temperature Photothermal Treatment of Urinary Tract Infection

Urinary tract infections (UTIs) caused by uropathogenic Escherichia coli (UPEC) have become a matter of concern because of the clinical use of multiple antibiotics, which results in antibiotic resistance in bacteria and causes the failure of treatments. Photothermal therapy (PTT) has been a high-potential method in antibacterial therapy on account of its noninvasion and avoiding bacterial resistance. However, high temperatures and nonselectivity related to PTT would cause serious damage to the surrounding healthy tissue. Herein, a surface-adaptive gold-based nanoplatform (AuNPs@GalNAc/DMMA-Cys) by conjugating N-acetylgalactosaminoside (GalNAc) and maleimidized cysteine (DMMA-Cys) on gold nanoparticles for low-temperature photothermal antibacterial therapy was proposed. The AuNPs@GalNAc/DMMA-Cys was characterized by the pH-activated photothermal effect on account of the translation from negative property to zwitterionic structure of DMMA-Cys and high adhesion toward UPEC originating from the recognition of GalNAc to FmlH protein. It can kill UPEC under low photothermal temperature but perform poorly against S. aureus. This approach may develop a promising tool for low-temperature photothermal antibacterial treatment.