Fig. 1.

Potential delivery systems for neurotrophic growth factor delivery in PD. To assess the therapeutic potential of neurotrophic factor therapy, direct infusion of the growth factor protein into the target brain region and in vivo gene therapy have progressed to clinical trials in patients with PD. However, one of the major hurdles to the clinical translation of growth factor therapeutics for PD remains issues related to the delivery of these protein drugs. To address this, other delivery systems, including ex vivo gene therapy and biomaterial-aided protein and gene delivery are in preclinical development.