Abstract
Afterglow imaging, leveraging persistent luminescence following light cessation, has emerged as a promising modality for surgical interventions. However, the scarcity of efficient near-infrared (NIR) responsive afterglow materials, along with their inherently low brightness and lack of cyclic modulation in afterglow emission, has impeded their widespread adoption. Addressing these challenges requires a strategic repurposing of afterglow materials that improve on such limitations. Here, we have developed an afterglow probe, composed of bovine serum albumin (BSA) coated with an afterglow material, a semiconducting polymer dye (PFODBT/SP1), called BSA@SP1 demonstrating a substantial amplification of the afterglow luminescence (∼3-fold) compared to polymer-lipid coated PFODBT (DSPE-PEG@SP1) under same experimental conditions. This enhancement is believed to be attributed to the electron-rich matrix provided by BSA that immobilizes SP1 and enhances the generation of1O2radicals, which improves the afterglow luminescence brightness. Through molecule docking, physicochemical characterization, and optical assessments, we highlight BSA@SP1’s superior afterglow properties, cyclic afterglow behavior, long-term colloidal stability, and biocompatibility. Furthermore, we demonstrate superior tissue permeation profiling of afterglow signals of BSA@SP1’s compared to fluorescence signals usingex vivotumor-mimicking phantoms and various porcine tissue types (skin, muscle, and fat). Expanding on this, to showcase BSA@SP1’s potential in image-guided surgeries, we implanted tumor-mimicking phantoms within porcine lungs and conducted direct comparisons between fluorescence and afterglow-guided interventions to illustrate the latter’s superiority. Overall, our study introduces a promising strategy for enhancing current afterglow materials through protein complexation, resulting in both ultrahigh signal-to-background ratios and cyclic afterglow signals.
Publisher
Cold Spring Harbor Laboratory