Chromaffin cell survival from both young and old donors is enhanced by co-grafts of polymer-encapsulated human NGF-secreting cells

Following polymer-encapsulation, human nerve growth factor-secreting baby hamster kidney fibroblasts (BHK-hNGF) were implanted into the striatum of hemiparkinsonian rats together with unencapsulated adrenal medullary chromaffin cells from either young (2 weeks) or old (12 months) donor rats. Animals receiving both BHK-hNGF cells and chromaffin cells exhibited significant decreases (39-56%) in apomorphine-induced rotational behaviour which was equivalent regardless of the age of the donor tissue. Histological analysis revealed that while survival of chromaffin cells without hNGF support was poor, co-grafts of adrenal medulla and BHK/hNGF cells increased chromaffin cell survival by 20 times. Again, this effect was independent of the age of the donor tissue. Retrieved capsules contained numerous viable encapsulated BHK-hNGF cells which continued to release hNGF. These results further indicate the potential use of intrastriatal implantation of encapsulated hNGF-secreting cells for augmenting the survival of co-grafted chromaffin cells as well as promoting the functional recovery of hemiparkinsonian rats.