Injectable and self-healing hydrogel as a stem cells carrier for treatment of diabetic erectile dysfunction

Diabetic erectile dysfunction has witnessed extensive preclinical and clinical explorations of intracavernous injection of stem cells therapy. However, intracavernous injection of stem cells for diabetic erectile dysfunction is challenged by rapid diffusion from cavernous sinus. Here, we found that a benzaldehyde terminated poly (ethylene glycol)/glycol chitosan (CHO-PEG/GCS) hydrogel with injectability and self-healability served as a stem cell carrier to prolong cell retention in corpus cavernosum. It was able to gelate under physiological condition and encapsulate adipose stem cells (ASCs) without reducing proliferation after injection. Encapsulated labelled ASCs presented higher fluorescence than non-encapsulated ones in the region of penis at 14 days after intracavernous injection in male rats. CHO-PEG/GCS hydrogel enhanced ASCs to ameliorate diabetes-induced fibrosis and apoptosis of CD31-positive endothelial cells, α-SMA-positive smooth muscle and NeuN-positive neural fibers 12 weeks post-operation. It also synergized with ASCs to elevate cGMP level and promote erectile function. CHO-PEG/GCS hydrogel serves as a promising stem cell carrier in conditions requiring injection and in situ gelation to prolong cell retention.