Near-infrared photoimmunotherapy (NIR-PIT) is an emerging cancer therapy based on conjugating monoclonal antibody (mAb) with a NIR phthalocyanine dye conjugate. Direct tumor necrosis and immunogenic cell death occur during NIR irradiation. We applied a multi-modal optical imaging approach including high-resolution optical coherence tomography (OCT) and high-sensitivity fluorescence mesoscopic tomography, to provide 3D tumor micro-structure and micro-distribution of mAb-IR700 in the tumor simultaneously during and after NIR-PIT in situ and in vivo. Moreover, label-free speckle variance algorithm combined OCT was applied to monitor the change of blood vessels and the alterations of the blood volume inside the blood vessels during and NIR-PIT treatment.

Metabolic control of immune cell function has emerged as a key regulatory mechanism in immunity. Current studies rely mainly on in vitro and ex vivo approaches to characterize the intracellular metabolism of immune cells. Here, we show that fluorescence lifetime imaging microscopy of metabolic coenzymes, NAD(P)H and FAD, captures dynamic changes in the metabolic activity of macrophages during diverse inflammatory responses in their native interstitial microenvironments. This imaging-based approach also provides single-cell resolution, in contrast to bulk measurements provided by traditional biochemical assays, making it a potentially valuable tool in the field of immunometabolism.