Alveolar echinococcosis (AE) is a serious parasitic infectious disease that is highly invasive and destructive to the liver and has a high mortality rate. However, currently, there is no effective targeted imaging and treatment method for the precise detection and therapy of AE. We proposed a new two-step targeting strategy (TSTS) for AE based on poly(lactic-co-glycolic acid) (PLGA). We designed and constructed a novel type of ICG@PLGA@Lips nanoprobe with integrated imaging and treatment properties. First, we used the characteristics of PLGA gluconeogenic raw material to target the liver during blood circulation. Then, we utilized the characteristics of PLGA specifically penetrating the AE shell to achieve specific identification of AE in the liver. Under 808 nm laser excitation, ICG@PLGA@Lips effectively achieved accurate imaging of AE based on near-infrared II (NIR-II, 900-1700 nm) fluorescence imaging methods and achieved AE treatment through PDT effects. PLGA improved the optical properties of ICG, while liposomes further improved the biocompatibility of the nanoprobe. As ICG@PLGA@Lips showed strong NIR-II fluorescence emission and good biocompatibility, ICG@PLGA@Lips showed advantages in the specific fluorescence navigation of AE surgical resection lesions. Thus, with the assistance of ICG@PLGA@Lips, we achieved precise targeted and real-time NIR-II fluorescence imaging of AE for the first time. We successfully obtained in vivo NIR-II fluorescence imaging-guided photodynamic/surgical therapy of AE. This TSTS-based AE imaging and treatment exploration provided a new strategy for accurate imaging and treatment of early AE, which is expected to significantly improve the prognosis of patients.
Keywords: NIR-II fluorescence imaging; PLGA; alveolar echinococcosis; photodynamic therapy (PDT); two-step targeting strategy.