Elevating Second Near-Infrared Photothermal Conversion Efficiency of Hollow Gold Nanorod for a Precise Theranostic of Orthotopic Bladder Cancer.

The second near-infrared (NIR-II) window laser-activated agents have attracted broad interest in an orthotopic cancer theranostic. However, developing NIR-II photothermal agents (PTAs) with advanced photothermal conversion efficiency (PTCE) and tumor-specific response elevation remains a crucial challenge. Herein, a hollow gold nanorod (AuHNR) with a strong localized surface plasmon resonance (LSPR) peak in the NIR-II window was coated with MnO 2 and chitosan to obtain AuHNR@MnO 2 @CS (termed AuMC) by a one-step method. Upon exposure to the tumor microenvironment (TME), the overexpressed GSH triggered degradation of the MnO 2 layer to release Mn 2+ and resulted in the PTCE elevation owing to exposure of the AuHNR. Consequently, photoacoustic and magnetic resonance imaging for accurate diagnosis, Mn 2+ -mediated chemodynamic therapy, and AuHNR elevating PT therapy for precise treatment could be achieved. Both in vitro and in vivo experiments confirmed the good performance of the AuMC on an orthotopic bladder cancer precise theranostic. This study provided NIR-II activated, TME-response PT conversion efficiency enhanced PTAs and offered a tumor-selective theranostic agent for orthotopic bladder cancer in clinical application.