Effect of polymer composition on in vivo ultrasound contrast agent performance

Polymer composition, the ratio of lactic acid (LA) to glycolic acid (GA), was evaluated for its contribution to the acoustic enhancement of a poly (co-lactic-glycolic) acid (PLGA) ultrasound contrast agent. Contrast agents were prepared from four different polymer compositions (LA:GA): 100:0, 85:15, 75:25, 50:50 and tested in vivo. The results indicate that all contrast agents perform well in vivo but the 50:50, which had the shortest usable life-time. The performance of the contrast agents was dependent on the ratio of LA to GA and should be considered in the design of polymeric contrast agents.