165 Optimization of Sonic Hedgehog Delivery from Self-assembled Nanofiber Hydrogels to prevent ED

Sonic hedgehog (SHH) protein delivered by nanoparticle based peptide amphiphile (PA) hydrogels to the penis and cavernous nerve (CN), improve erectile function, promote CN regeneration, and suppress apoptosis in a rat CN injury model. We examine the hypothesis that suppression of apoptosis and penile morphology changes after CN crush will be maximized with optimization of SHH delivery to both the penis and CN via PA hydrogels. Optimization of delivery conditions is essential for clinical translation to prostatectomy patients. Study was divided into 3 parts: 1.Optimization of SHH protein concentration delivered to penis, 2. Maintain elevated SHH protein longer with 2 SHH PA injections, 3. Examine additive effects with SHH delivery to both penis and CN. Bilateral CN crush was performed on Sprague Dawley rats (n=67) and SHH or mouse serum albumin (MSA, control) protein was delivered by PA injected into the corpora cavernosa. Rats were sacrificed after 4 and 9 days. 2X SHH protein was also assayed at 4 days. A second SHH PA injection at 5 days occurred prior to sacrifice at 9 days. Additional rats had SHH or MSA delivered to both the penis and CN by PA. TUNEL, trichrome stain and western analysis were performed.