Efferocytosis-Inspired Biomimetic Nanoplatform for Targeted Acute Lung Injury Therapy.

Acute lung injury (ALI) is a serious inflammatory disease that causes impairment of pulmonary function. Phenotypic modulation of macrophage in the lung using fibroblast growth factor 21 (FGF21) may be a potential strategy to alleviate lung inflammation. Consequently, achieving specific delivery of FGF21 to the inflamed lung and subsequent efficient FGF21 internalization by macrophages within the lung becomes critical for effective ALI treatment. Here, an apoptotic cell membrane-coated zirconium-based metal-organic framework UiO-66 is reported for precise pulmonary delivery of FGF21 (ACM@U-FGF21) whose design is inspired by the process of efferocytosis. ACM@U-FGF21 with apoptotic signals is recognized and internalized by phagocytes in the blood and macrophages in the lung, and then the intracellular ACM@U-FGF21 can inhibit the excessive secretion of pro-inflammatory cytokines by these cells to relieve the inflammation. Utilizing the homologous targeting properties inherited from the source cells and the spontaneous recruitment of immune cells to inflammatory sites, ACM@U-FGF21 can accumulate preferentially in the lung after injection. The results prove that ACM@U-FGF21 effectively reduces inflammatory damage to the lung by modulating lung macrophage polarization and suppressing the excessive secretion of pro-inflammatory cytokines by activated immune cells. This study demonstrates the usefulness of efferocytosis-inspired ACM@U-FGF21 in the treatment of ALI.