A nanoplatform of hollow Ag2S/Ag nanocomposite shell for photothermal and enhanced sonodynamic therapy mediated by photoacoustic and CT imaging

Abstract In this study, a hollow Ag2S/Ag nanocomposite shell comprised of elemental Ag and compound Ag2S was synthesized, after loading the sonosensitizer and CT contrast agent, a multifunctional HASAIC nanoprobe was obtained for the first time by wrapping it with a thermosensitively supported lipid bilayer. The elemental Ag in the probe can catalyze H2O2 to O2 to relieve the hypoxic environment at the tumor site and improve the effect of sonodynamic therapy. Moreover, the hollow Ag2S/Ag nanocomposite shell avoids the key limitation of pure Ag shell during the process of catalyzing H2O2 to O2, the pure Ag shell will dissolve and could not be used for photothermal therapy (PTT) and photoacoustic imaging (PAI), and enables the probe to use stable Ag2S to employ PTT and PAI though solving the problem of hypoxia. The synergy combination of the nano size (70 nm) HASAIC probe, low cytotoxicity, good safety, and high biocompatibility boost up the tumor killing capability. Because of the high efficiency, the HASAIC nanoprobe has been employed for real-time (in vitro and in vivo) CT and PAI imaging in a 4T1 tumor-bearing mouse. Laser and ultrasound irradiation demonstrated a higher survival rate of HASAIC-injected mice compared to a probe without elemental silver, thereby indicating the high efficiency of our diagnosis and treatment probe.