Biologically Responsive Plasmonic Assemblies for Second Near-Infrared Window Photoacoustic Imaging-Guided Concurrent Chemo-Immunotherapy
Rong Zhu, Lichao Su, Jiayong Dai, Zhan‐Wei Li, Shumeng Bai, Qingqing Li, Xiaoyuan Chen, Jibin Song, Huanghao Yang
Abstract
We developed dual biologically responsive nanogapped gold nanoparticle vesicles loaded with immune inhibitor and carrying an anticancer polymeric prodrug for synergistic concurrent chemo-immunotherapy against primary and metastatic tumors, along with guided cargo release by photoacoustic (PA) imaging in the second near-infrared (NIR-II) window. The responsive vesicle was prepared by self-assembly of nanogapped gold nanoparticles (AuNNPs) grafted with poly(ethylene glycol) (PEG) and dual pH/GSH-responsive polyprodug poly(SN38-co-4-vinylpyridine) (termed AuNNP@PEG/PSN38VP), showing intense PA signal in the NIR-II window. The effect of the rigidity of hydrophobic polymer PSN38VP on the assembled structures and the formation mechanism of AuNNP@SN38 Ve were elucidated by computational simulations. The immune inhibitor BLZ-945 was encapsulated into the vesicles, resulting in pH-responsive release of BLZ-945 for targeted immunotherapy, followed by the dissociation of the vesicles into single AuNNP@PEG/PSN38VP. The hydrophilic AuNNP@PEG/PSN38VP nanoparticles could penetrate deep into the tumor tissues and release the anticancer drug SN38 under the reductive environment. A PA signal in the NIR-II window in the deep tumor region was obtained. The BLZ-945-loaded vesicle enabled enhanced PA imaging-guided concurrent chemo-immunotherapy efficacy, inhibiting the growth of both primary tumors and metastatic tumors.