Comparison between subcutaneous injection of basic fibroblast growth factor-hydrogel and intracavernous injection of adipose-derived stem cells in a rat model of cavernous nerve injury.

Abstract

To compare the effects of subcutaneous penile injection of basic fibroblast growth factor (bFGF)-hydrogel and intracavernous injection of human adipose-derived stem cells (h-ADSCs) on improving erectile function in a rat model of cavernous nerve injury. Adult male Sprague-Dawley rats were randomly divided into 5 groups (n = 10 per group): age-matched control (normal group), bilateral cavernous nerve injury (BCNI group), penile subcutaneous injection of hydrogel after BCNI (hydrogel group), penile subcutaneous injection of bFGF-hydrogel after BCNI (bFGF-hydrogel group) and intracavernous injection of h-ADSCs after BCNI (ADSC group). Four weeks after the treatment, all rats underwent an erectile function test. Then, penile tissue was harvested for immunohistological analysis of bFGF, phalloidin, and cluster of differentiation (CD) 31. The cyclic guanosine monophosphate (cGMP) level of the corpus cavernosum was quantified by cGMP assay. From the functional test and immunohistological result, we observed that bFGF-hydrogel and h-ADSCs injection significantly elevated intracavernous pressure. The evaluation of filamentous actin content, CD31 expression, and cGMP concentration in the corpus cavernosum were meaningfully increased in the bFGF-hydrogel and ADSC groups compared with BCNI group. The bFGF released from bFGF-hydrogel prevented smooth muscle atrophy. Moreover, bFGF expression was significantly increased in bFGF-hydrogel group. The subcutaneous injection of bFGF-hydrogel prevented smooth muscle atrophy, increased the intracavernous pressure, and improved erectile function like an intracavernous injection of h-ADSCs.