For systemic delivery 40 μg of DNA and 4.8 μL of 150 mM in vivo-jetPEI® was diluted in endotoxin-free 5% (wt/vol) glucose separately. The glucose solutions of DNA and l-PEI polymer were then mixed together to give an N:P ratio of 6:1 in a total volume of 400 μL. The DNA-PEI polyplex was injected IV as two 200 μL injections with a 5 min interval.

We describe a new imaging method for detecting prostate cancer, whether localized or disseminated and metastatic to soft tissues and bone. The method relies on the use of imaging reporter genes under the control of the promoter of AEG-1 (MTDH), which is selectively active only in malignant cells. Through a systemic, nanoparticle-based delivery of the imaging construct, lesions can be identified through bioluminescence imaging and single-photon emission computed tomography in the PC3-ML murine model of prostate cancer at high sensitivity. This approach is applicable for the detection of prostate cancer metastases, including bone lesions for which there is no current reliable agent for noninvasive clinical imaging. Furthermore, the approach compares favorably with accepted and emerging clinical standards, including PET with [(18)F]fluorodeoxyglucose and [(18)F]sodium fluoride. Our results offer a preclinical proof of concept that rationalizes clinical evaluation in patients with advanced prostate cancer.