Effects of coencapsulated NGF and GM1 in rats with cortical lesions.

Nerve growth factor (NGF) and monosialoganglioside GM1 were microencapsulated in biodegradable co-polymer poly(L-lactide):co-glycolide and administered locally to rats with unilateral cortical devascularizing lesions. Microcapsules were placed directly onto the lesioned cortical surface and rats were sacrificed 30 days post-operatively. Biochemical and quantitative immunocytochemical analyses revealed effective protection from degenerative changes of nucleus basalis magnocellularis (NBM) cholinergic neurones on the lesioned side as well as a significant increase in choline acetyltransferase activity in the frontoparietal cortex surrounding the lesion. Results of this study strongly suggest that the topical application of microcapsules of a biodegradable polymer containing a mixture of two neuroprotective factors is a viable alternative to the use of osmotic minipumps for delivery of these agents into the CNS. Indeed, this approach might find clinical applications.