Cytokine-induced killer cells-mediated chlorin e6-loaded gold nanostars for targeted NIR imaging and immuno-photodynamic combination therapy for lung cancer.

Recently, cytokine-induced killer (CIK) cells have a broad application prospect in the comprehensive diagnosis and treatment of tumors owing to their unique characteristics of killing and targeting malignant tumors. Herein, we report a facile strategy for synthesis of monodisperse gold nanostars (GNSs) based on PEGylation and co-loaded with the photosensitizer chlorin e6 (Ce6) to form GNSs-PEG@Ce6 NPs. Then employing CIK cells loading the as-prepared GNSs-PEG@Ce6 NPs to fabricate a CIK cells-based drug delivery system (GNSs-PEG@Ce6-CIK) for lung cancer. Among them, GNSs was functioned as transport media, Ce6 acted as the near-infrared (NIR) fluorescence imaging agent and photodynamic therapy (PDT), and CIK cells served as targeting vectors for immunotherapy, which can increase the efficiency of tumor enrichment and treatment effect. The results of cellular experiments demonstrated that GNSs-PEG@Ce6 NPs had good dispersibility, water solubility and low toxicity under physiological conditions, and the cultured CIK cells had strong anti-tumor properties. Subsequently, GNSs-PEG@Ce6-CIK could effectively inhibit the growth of A549 cells under the exposure of 633 nm laser, which showed stronger killing effect than that of GNSs-PEG@Ce6 NPs or CIK cells. In addition, they showed good tumor targeting and tumor synergistic killing activityin vivo. Therefore, GNSs-PEG@Ce6-CIK was constructed for targeted NIR fluorescence imaging, enhanced PDT and immunotherapy of lung cancer.