Neutrophil-mediated clinical nanodrug for treatment of residual tumor after focused ultrasound ablation

BACKGROUND: The risk of local recurrence after high-intensity focused ultrasound (HIFU) is relatively high, resulting in poor prognosis of malignant tumors. The combination of HIFU with traditional chemotherapy continues to have an unsatisfactory outcome because of off-site drug uptake. RESULTS: Herein, we propose a strategy of inflammation-tendency neutrophil-mediated clinical nanodrug targeted therapy for residual tumors after HIFU ablation. We selected neutrophils as carriers and PEGylated liposome doxorubicin (PLD) as a model chemotherapeutic nanodrug to form an innovative cell therapy drug (PLD@NEs). The produced PLD@NEs had a loading capacity of approximately 5 µg of PLD per 10(6) cells and maintained the natural characteristics of neutrophils. The targeting performance and therapeutic potential of PLD@NEs were evaluated using Hepa1-6 cells and a corresponding tumor-bearing mouse model. After HIFU ablation, PLD@NEs were recruited to the tumor site by inflammation (most in 4 h) and released PLD with inflammatory stimuli, leading to targeted and localized postoperative chemotherapy. CONCLUSIONS: This effective integrated method fully leverages the advantages of HIFU, chemotherapy and neutrophils to attract more focus on the practice of improving existing clinical therapies. GRAPHICAL ABSTRACT: [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12951-021-01087-w.