Figure 7.

Intratracheal Transfection of 4T1-iRFP720 Tumor-Bearing Lungs

4T1-iRFP720 tumor-bearing BALB/c mice were treated with polyplexes based on pCpG-hCMV-EF1α-LucSH and LPEI-PEG-CD49f or LPEI-PEG at N/P 9 and a concentration of 267 μg/mL. In total, 20 μg of formulated pDNA was administered by intratracheal (i.t.) aerosolization. Twenty-four hours posttreatment, firefly luciferase expression was analyzed by in vivo BLI imaging. T2-weighted MRI was conducted 1 or 2 days before treatment for evaluating the status of tumor growth. (A–L) Both BLI and MRI were done in supine positioning of the animal. Three representative animals treated with LPEI-PEG-CD49f (A, E, and I show MRI of animals 1, 2, and 3, respectively; B, F, and J show BLI of animals 1, 2, and 3, respectively) and LPEI-PEG (C, G, and K show MRI of animals 1, 2, and 3, respectively; D, H, and L show BLI of animals 1, 2, and 3, respectively) polyplexes are depicted. Tumor growth is marked with yellow arrows in the MRI images. BLI signals (color coded) are overlaid on a reflected light picture.