FLUORINATED POLY(LACTIC-CO-GLYCOLIC ACID) POLYMERS AND CORRESPONDING NANOPARTICLES AND DRUG ENCAPSULATED NANOPARTICLES

Described herein are fluorinated poly(lactic-co-glycolic acid) polymers ("PLGA"). Also described herein are fluorinated PLGA nanoparticles, drug encapsulated fluorinated PLGA nanoparticles, and corresponding dispersions. Relative to corresponding non-fluorinated PLGA nanoparticles, the fluorinated PLGA nanoparticles have desirable 19F nuclear magnetic resonance ("NMR") activities and concomitant relaxation times for use as 19F magnetic resonance imaging ("MRI") probes. It was surprisingly found that, for some fluorinated PLGA nanoparticle embodiments, the 19FNMR activity (and therefore the 19FMRI activity) could be tuned (e.g. turned on an off) by changing the pH of the nanoparticle dispersion. It was also surprisingly discovered that the 19FNMR activity could also be tuned by adjusting the relative concentration of the polar organic solvent to water in the formation medium, as described in detail below. Because the fluorinated PLGA nanoparticles include, by definition, fluorine, dmg loading and encapsulation efficiency is also significantly increased for fluorine containing drugs, relative to corresponding non-fluorinated PLGA.