Biooptical methods for in vivo imaging

Optical methods gain increasing importance in drug research but also in clinical diagnostics. Luciferase is extensively used as a marker gene in transgenic animals but also for gene marking studies, as its activity can be monitored in the living organism over time with the help on bioluminescence imaging (BLI). We apply the concept of stable gene marking with different types of luciferase enzymes. Tumor cells are stably transfected ex vivo with lentiviral vectors and thereafter sorted by flow cytometry. Optimized variants of the firefly luciferase gene are utilized to monitor tumor development in vivo, like the growth of tumor metastases. With the help of BLI we can also follow the transgene expression of reporter genes deliverd with our nucleic acid delivery platforms.

Fluorescent dyes emitting light in the near infrared (NIR) are highly advantageous for in vivo imaging studies, as near infrared light is less prone to quenching by organs or blood components like hemoglobin. NIR emitting dyes are already used in clinical applications to monitor blood flow or in tumor diagnostics. We utilize these imaging principles to study pharmacokinetics and pharmacodynamics of our macromolecular drug carriers.

Further information of NIR and BLI imaging can be found in our publication Zintchenko et al, which is freely accessible from PubMed Central® (PMC).