137 Superparamagnetic Iron Oxide Nanoparticle Targeting of Adipose Tissue-Derived Stem Cells in Diabetes-Associated Erectile Dysfunction

Abstract

To explore the effect of Adipose tissue-derived stem cells (ADSCs) labelled with superparamagnetic iron oxide nanoparticles (SPIONs) on improving the erectile function of streptozocin (STZ)-induced diabetic rats with an external magnetic field. Ten-week-old male Sprague Dawley rats were injected either with STZ to induce diabetes or citrate buffer as controls. Rat ADSCs were harvested and labelled with SPIONs, and then transplanted into corpus cavernosum of STZ-induced diabetic rats with or without an external magnetic field. At 28 days after transplantation, all rats were sacrificed for tracking of transplanted cells. Erectile response was assessed by cavernous nerve stimulation. Smooth muscle, endothelium and vascular endothelial growth factor (VEGF) expression in corpora cavernosum were assessed using immunohistochemistry. In vitro studies revealed that stem cell properties were minimally affected by SPION labeling. With magnetic targeting, SPION-labelled ADSCs were visibly attracted toward the magnet field. In vivo experiments, magnetic targeting of ADSCs contributed to long-term cell retention in corpus cavernosum and improved the erectile function of diabetic rats compared with ADSC injection alone. ADSCs were identified in the corpus cavernosums of diabetic rats at 28 days after transplantation, and they were negative for vWF and a-SMA, indicating that ADSCs did not differentiate into endothelial or smooth muscle cells. VEGF expression in the corpus cavernosum was significantly increased in both ADSC-treated groups compared with the PBS-treated group. The underlying mechanism of recovery appears to the paracrine mechanism of transplanted ADSCs.