In vitro and in vivo testing of PLGA contrast agents

We have optimized a method for producing hollow poly (lactide-co-glycolide) (PLGA) microcapsules with a mean size of 1 /spl mu/m by a modified double emulsion, solvent evaporation technique. Besides being biocompatible and biodegradable, these microspheres exhibit acoustic enhancements that makes them useful as contrast agents for diagnostic ultrasound imaging. In vivo studies (rabbit) demonstrate significant enhancement of power Doppler images. Moreover, the capsules' solid shells makes them ideal candidates for the use as drug delivery vehicles for targeted/triggered therapeutic imaging.