Encapsulation of small molecules in polymer nanoparticles through kinetic trapping

E. Van Keuren, M. Mugnai, O. Bulgin, F. Diaz Ruiz, Y. Chung, A. Stevens, M. Mullin, E. Bird, K. Jeon, M. Snideman
Georgetown University,
United States

Keywords: flash nanoprecipitation, polymer nanocarriers

Summary:

Polymeric nanoparticles are extensively employed as vehicles for therapeutic deliver of small molecule active pharmaceutical ingredients (APIs). Numerous methods have been developed for encapsulation, many of them relying on attractive interactions in order to ensure that the small molecules mainly partition into the polymer. We have shown that the method of flash nanoprecipitation (FNP), in which a solution of polymer and API is rapidly mixed with a miscible non-solvent, can effectively encapsulate small molecules even when the affinity between the polymer and molecule is low. We attribute this to kinetic trapping of small molecules in the polymer network during formation, interpreted using the droplet model approach. We will discuss data from some model systems as well as applications in drug delivery.