PolyPEG star polymers have potential utility as cost-effective polymeric drug delivery vehicles, and as such, it is important to develop an understanding of their biopharmaceutical behavior. Moreover, although a number of studies have evaluated the utility of PolyPEG stars in vitro, investigation of these novel materials in vivo has been limited. Herein, we evaluated the pharmacokinetics of a 64 kDa tritiated PEG-based star polymer after subcutaneous and pulmonary administration in rats. After subcutaneous administration, the star polymer showed near complete bioavailability (∼80%) and a similar organ biodistribution profile to the polymer after intravenous administration. After intratracheal instillation to the lungs, the star polymer showed limited bioavailability (∼3%), and most of the administered radiolabel was recovered in lung tissue and feces after 6 d. The data reported here suggest that star polymers display similar pharmaceutical behavior to PEGylated dendrimers after subcutaneous and inhaled delivery and may therefore be used as similar, but more cost-effective drug delivery vehicles.
- star polymers