Neuroprotective effect of erythropoietin-loaded composite microspheres on retinal ganglion cells in rats.

This study explored a sustained neuroprotective erythropoietin (EPO) loaded composite microspheres system on injured retinal ganglion cells (RGC). The EPO was first loaded into dextran microparticles to keep its bioactivity using a novel "aqueous-aqueous emulsion" technique. The microspheres were finally formed by encapsulating the microparticles into Poly (DL-lactide-co-glycolide)/Poly (DL-lactide) (PLGA/PLA). A single dose of microspheres was intraperitoneally administrated on the optic nerve crush of rats and compared with multiple doses of EPO solution to investigate the long acting effect of microspheres on RGC. The results demonstrated that the release of microspheres could last for at least 60 days in an in vitro study. The animal experiments showed a similar neuroprotective effect between the single dose microspheres and the multiple doses of EPO solution. So we can draw a conclusion that the EPO-loaded PLGA/PLA microspheres were feasible for neurodegeneration diseases in the retina and central nervous system (CNS).