Stem Cell/Oxygen-Releasing Microparticle Enhances Erectile Function in a Cavernous Nerve Injury Model

Erectile dysfunction caused by damage to the cavernous nerve is a common complication of radical prostatectomy for patients with localized prostate cancer. Various studies have investigated repair of damaged tissue and prevention of fibrosis in the corpus cavernosum using stem cell therapy. However, stem cell therapy has limitations, including insufficient nutrient and oxygen supply to transplanted stem cells. This study investigated whether stem cell/oxygen-releasing hollow microparticles (HPs) had therapeutic effect on erectile dysfunction in a rat model of bilateral cavernous nerve injury (BCNI). Therapeutic effects were observed in the BCNI model at 1, 2, and 4 weeks postcavernous nerve injury. Erectile function further improved after treatment with stem cell/oxygen-releasing HP system compared with treatment with only stem cells at 4 weeks. Stem cell/oxygen-releasing HP system increased cyclic guanosine monophosphate (cGMP) level and neuronal nitric oxide synthase (nNOS), endothelial nitric oxide synthase (eNOS), α-smooth muscle actin (α-SMA), and muscarinic acetylcholine receptor 3 (M3) expression while decreasing fibrosis and apoptosis in the corpus cavernosum. Our results clearly show that stem cell survival increases around transplanted stem cell/oxygen-releasing hybrid system site. Taken together, an oxygen-releasing HP system supported prolonged stem cell survival, sustaining the paracrine effect of the stem cells, and consequently enhancing erectile function. These findings show promise with regard to prolonged stem cell survival in stem cell applications for various diseases and types of tissue damage.