Sustained Release of VEGF from Gadolinium Doped Biodegradable Microspheres

Biodegradable microspheres are effective devices for controlled drug release, and it is desireable to be able to monitor their distribution in vivo in order to optimize delivery methods. Biodegradable microspheres coencapsulating Gd-DTPA and human vascular endothelial growth factor (VEGF) were made from poly(1actic-co-glycolic acid) (PLGA). The release of VEGF from the spheres was measured and was found to follow a characteristic burst followed by a steady state release profile. The spheres were injected into the hindlimb of a rabbit and were easily visualized under MRI, allowing their delivery and distribution to be monitored.