Synthesis and characterization of environmentally benign, semifluorinated polymers and their applications in drug delivery

Abstract

We describe the synthesis, physicochemical studies and pharmaceutical assessment of a class of pegylated semifluorinated amphiphilic block-copolymers based on short pendant fluorinated side chains attached to moderately hydrophobic units. These polymers allowed us to investigate how the balance between hydrophobicity and fluorophilicity in the polymer can be tuned to match that of small molecules to be used in drug delivery. Remarkably, we found that using short perfluoroethyl groups in the polymer allows the preferential stabilization of nanoemulsions based on isoflurane, a fluorinated anesthetic made partly hydrophobic by the presence of a chlorine atom. In comparison, nanoemulsions of sevoflurane, a purely fluorophilic anesthetic, were not as stable. The lipophilicity of the polymers was also investigated in regards to solvation of hydrophobic molecules. Surface properties such as critical micelle concentration (CMC) and surface tension demonstrated the uniqueness of these fluorinated amphiphiles. Finally, the use of short perfluoroethyl chains makes these polymers environmentally benign in terms of bioaccumulation and toxicity.