2.14. In Vivo Targeting and Biodistribution of NPs in a Mouse Model

We created the mouse model as mentioned above. After 2 h, mice were intravenously injected with mAb-TPCA-1@HCNPs (n = 4), and the dose of DiR was 2 mg/kg. In addition, healthy mice and model mice intravenously injected with free DiR and isotype IgG-DiR@HCNPs were used as control groups. After 24 h, mice were euthanized, and their organs were collected. Subsequently, the fluorescence intensity of the organs was detected on a Lago X Imaging System (Spectral Instruments Imaging, USA). For the histological study, model mice were intravenously injected with mAb-C6@HCNPs to label NPs. Then, we collected the lungs, fixed them in 4% paraformaldehyde, and embedded them in paraffin. After a series of workflows, we used a CD68 primary antibody followed by cyanine 5-conjugated secondary antibody incubation to detect macrophages. All slides were analyzed using a fluorescence microscope (Olmypus, Tokyo, Japan).