Resonance energy transfer for assessing the molecular integrity of proteins for local delivery.
It remains unclear whether the limitations to the therapeutic potential of angiogenic growth factors stem from pharmacokinetic concerns related to inadequate delivery or from a reduced sensitivity of target tissues. Here, we report a novel method using resonance energy transfer to assess the molecular integrity of proteins after local delivery. As an example, we labeled fibroblast growth factor-2 with a fluorescent donor and nonfluorescent acceptor pair, tetramethylrhodamine and QSY-7, and demonstrate in an ex vivo bovine carotid artery model that this growth factor is not limited by proteolytic constraints imposed by the tissue. Our data indicate that FGF-2 is unlikely to be degraded within the arterial wall and suggest that pharmacokinetic limitations alone cannot fully explain the muted response seen thus far in therapeutic angiogenesis. In general, resonance energy transfer may serve as a novel approach to assess the molecular integrity of protein-based therapies in local delivery.
Wu
David
D
Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 USA. david_wu@alum.mit.edu
Edelman
Elazer R
ER
D000818:Animals; D002339:Carotid Arteries / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D002417:Cattle; D046508:Culture Techniques; D016503:Drug Delivery Systems / Q000379:methods*; D004355:Drug Stability; D016222:Fibroblast Growth Factor 2 / Q000008:administration & dosage / Q000493:pharmacokinetics*; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D008657:Metabolic Clearance Rate; D018919:Neovascularization, Physiologic / Q000187:drug effects; D014018:Tissue Distribution
D016222:Fibroblast Growth Factor 2