Specific Lung-Targeting Shortwave Infrared Luminescence Nanoprobe: Precisely Delineating Sepsis-Induced Acute Lung Injury.

Sepsis-induced acute lung injury (ALI), a life-threatening condition, necessitates a deeper molecular-level understanding to promote the development of therapeutic strategies. Although hydrogen sulfide (H2S) has been implicated in sepsis-associated ALI, current detection methods and poor pulmonary targeting have limited mechanistic insights. In this study, we present a lung-targeted shortwave infrared (SWIR) nanoprobe (RENPs@PB@LIP) for noninvasive monitoring of H2S in ALI though a novel mismatched resonance energy transfer (MRET) strategy. Specifically, the emission around 1475 nm from Tm3+-doped rare-earth doped nanoparticles (RENPs) can be quenched by Prussian blue (PB), which absorbs light in the 600-900 nm range, via modulating the shared energy level of the emissions at 1475 and 812 nm. This energy modulation allows for the detection of H2S through PB degradation upon reaction. Additionally, positively charged liposomes encapsulate the nanoprobe, promoting its preferential accumulation in the lungs over the liver. Our system enables timely, noninvasive monitoring of H2S levels in the lungs and facilitates the assessment of ALI progression and prognosis in vivo. This approach holds significant potential for elucidating the pathogenesis of ALI and guiding therapeutic interventions.