Nanoparticle Improved Stem Cell Therapy for Erectile Dysfunction in a Rat Model of Cavernous Nerve Injury

Purpose: Recently intracavernous injection of stem cells has garnered great interest as a potential treatment of erectile dysfunction. However, most stem cells are washed out immediately after intracavernous injection. The goal of this study was to investigate using NanoShuttle (TM) magnetic nanoparticles to maintain stem cells in the corpus cavernosum after intracavernous injection, thereby improving stem cell therapy of erectile dysfunction in an animal model. Materials and Methods: Adipose derived stem cells were magnetized with NanoShuttle magnetic nanoparticles to create Nano-adipose derived stem cells. A total of 24 rats underwent bilateral cavernous nerve crush and were randomly assigned to 3 groups, including adipose derived stem cells, Nano-adipose derived stem cells and Nano-adipose derived stem cells plus magnet. Cells were tracked at days 1, 3, 5 and 9 after intracavernous injection. Another 40 rats with bilateral cavernous nerve crush were randomly assigned to 4 groups, including bilateral cavernous nerve crush, bilateral cavernous nerve crush plus adipose derived stem cell intracavernous injection, bilateral cavernous nerve crush plus Nanoadipose derived stem cell intracavernous injection and bilateral cavernous nerve crush plus Nano-adipose derived stem cell intracavernous injection plus magnet. Functional testing and histological analysis were performed 4 weeks after intracavernous injection. Results: In the in vitro study 1) NanoShuttle magnetic nanoparticles were successfully bound to adipose derived stem cells and 2) Nano-adipose derived stem cells migrated toward the magnet. In the in vivo study 1) cell tracking showed that Nano-adipose derived stem cells were successfully retained in the corpus cavernosum using the magnet for up to 3 days while most adipose derived stem cells were washed out in other groups by day 1 after intracavernous injection, and 2) intracavernous pressure/mean arterial pressure, and aSMA (a-smooth muscle actin) and PECAM-1 (platelet endothelial cell adhesion molecule 1) expression in the Nano-adipose derived stem cell group was significantly higher than in the other groups. Conclusions: Magnetization of adipose derived stem cells with NanoShuttle magnetic nanoparticles kept adipose derived stem cells in the corpus cavernosum and improved adipose derived stem cell therapy of erectile dysfunction in an animal model.