Sustained Intracerebral Delivery of Nerve Growth Factor with Biodegradable Polymer Microspheres

We have demonstrated that the microencapsulation of biologically active NGF is possible. With this technique, sustained delivery of NGF occurred with minimal trauma and tissue reaction. Moreover, local targeted delivery of this factor can be attained, reducing the exposure of nontargeted tissue. The supplementation of adrenal medullary grafts with NGF delivered from these biodegradable microspheres resulted in a marked behavioral improve ment compared to non-NGF-supplemented grafts. This difference persisted during a period of time in which NGF was probably being released from the microspheres. These studies demonstrate that biodegradable, biocompatible polymers for the local intracerebral administration of macromolecules is a viable strategy for providing pharmacological access to the brain.