To create the Calu-3 tumor-bearing mouse model, Calu-3 cells (1 × 107 cells) were resuspended in 100 μL culture media and subcutaneously injected into the right-back of male and female BALB/c nude mice (22–35 g). The fluorescent dye 1,1′-Dioctadecyl-3,3,3′,3′ tetramethylindotricarbocyanine iodide (DiR) was used to replace 5-Dox in the formulation [60 (link)]. Tumor-bearing nude mice were randomly separated into two groups (n = 3) and intravenously injected with free DiR and PSL-DiR at a dosage of 200 μg kg−1 of DiR, respectively, when the tumor volume reached around 100–150 mm3. The mice were anesthetized and photographed using in vivo imaging equipment (IVIS® Lumina, PerkinElmer, USA) at 3, 8, and 24 hours after injection. The mice were killed after 24 h post-injection, and the major organs (heart, liver, spleen, lung, and kidney), as well as tumors, were taken for ex vivo imaging (IVIS® Lumina, PerkinElmer, USA).
Another biodistribution study was conducted with the same procedure and injected with Free Dox, PS5-DoxL, and NPS5-DoxL at a dosage of 600 mg kg−1 of Dox [61 (link)]. The mice were killed after 24 h post-injection, and the major organs (heart, liver, spleen, lung, and kidney), as well as tumors, were taken for ex vivo imaging (IVIS® Lumina, PerkinElmer, USA).
Another biodistribution study was conducted with the same procedure and injected with Free Dox, PS5-DoxL, and NPS5-DoxL at a dosage of 600 mg kg−1 of Dox [61 (link)]. The mice were killed after 24 h post-injection, and the major organs (heart, liver, spleen, lung, and kidney), as well as tumors, were taken for ex vivo imaging (IVIS® Lumina, PerkinElmer, USA).