- Faranesh, A.Z. and Nastley, M.T. and de la Cruz, C.P. and Haller, M.F. and Laquerriere, P. and Leong, K.W. and McVeigh, E.R., In vitro release of vascular endothelial growth factor from gadolinium-doped biodegradable microspheres,
Magn. Reson. Med. (USA), vol. 51 no. 6
pp. 1265 - 71 [mrm.20092] .
(last updated on 2007/04/13)
A drug delivery vehicle was constructed that could be visualized noninvasively with MRI. The biodegradable polymer poly(DL-lactic-co-glycolic acid) (PLGA) was used to fabricate microspheres containing vascular endothelial growth factor (VEGF) and the MRI contrast agent gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA). The microspheres were characterized in terms of size, drug and contrast agent encapsulation, and degradation rate. The PLGA microspheres had a mean diameter of 48±18 μm. The gadolinium loading was 17±3 μg/mg polymer and the VEGF loading was 163±22 ng/mg polymer. Electron microscopy revealed that the Gd was dispersed throughout the microspheres and it was confirmed that the Gd loading was sufficient to visualize the microspheres under MRI. VEGF and Gd-DTPA were released from the microspheres in vitro over a period of ~6 weeks in three phases: a burst, followed by a slow steady-state, then a rapid steady-state. Biodegradable Gd-doped microspheres can be effectively used to deliver drugs in a sustained manner, while being monitored noninvasively with MRI
biochemistry;biomedical MRI;blood vessels;drug delivery systems;electron microscopy;encapsulation;gadolinium;molecular biophysics;polymers;prosthetics;proteins;