Vasculogenic erectile dysfunction (ED) due to endothelial dysfunction and atherosclerosis of penile arteries is the most common cause of ED, especially in men over fifty. Cell-based regenerative therapies include platelet-rich plasma (PRP), both heterologous and autologous stem cell therapy (SCT), and peripheral blood mononuclear cells (PBMNC), highlighting the role played by immune cell populations, which may represent the new frontier of vasculogenic erectile dysfunction treatment.
Stem cells (SCs) are undifferentiated cells capable of unlimited proliferation, multi-differentiation potency, and perpetual self-renewal. The specific mechanisms underlying the effectiveness of SCs in the treatment of ED are not yet understood. Since pre-clinical studies have shown that few stem cells can be detected after transplantation, and almost no direct evidence supports the theory that transplanted stem cells have differentiated into vascular endothelial cells, smooth muscle cells, or nerves, the main mechanisms of action of stem cell transplantation would seem to be related to their paracrine action .
Moreover, preclinical research has shown that SCs exert their therapeutic effects on the basis of active factors contained in their secretions that can act as messengers. Indeed, the effect of SCs has been shown to persist after their disappearance, and even cell-free treatments have shown benefits . Bioactive factors may represent a future treatment option for ED due to their pro-angiogenic, anti-inflammatory, anti-apoptotic, and anti-fibrotic properties .