Stem cell therapy for bladder regeneration: A comprehensive systematic review

Tissue engineering has been considered a potential choice for urinary system reconstruction. Here, we aim to a broad spectrum of employed stem cells in bladder regeneration by performing a comprehensive systematic review. In January 2024, we searched Scopus, PubMed, and Embase databases for studies that tried bladder regeneration by tissue engineering using stem cells. We excluded non-English studies, review articles, and manuscripts that met the other exclusion criteria. Among 43 included studies, comparative studies demonstrated the similar or superior potentiality of stem cells to regenerate tissues and improve bladder function compared with autologous cells. Furthermore, data suggest an increased use of bio-synthetic scaffolds and their appropriate bio-compatibility with stem cells. The evidence establishes that adipose-derived and bone marrow-derived mesenchymal stem cells are the most frequently used stem cells. And both are suitable for urothelium and smooth muscle formation along with the capability of bone marrow-derived mesenchymal stem cells for lamina propria formation. Additionally, the competency of smooth muscle-derived progenitor cells, urine-derived stem cells, umbilical mesenchymal SCs for smooth muscle and urothelium regeneration, and the capability of hair follicle stem cells for smooth muscle formation are demonstrated. Also, the superiority of endothelial progenitor cells for neo-vascularization and smooth muscle progenitor cells for neuron formation are demonstrated. In addition to adding growth factors to the culturing media, hypoxic conditions and intra-peritoneal incubation are introduced as promoter conditions that can improve histological and physiological components. Available evidence is limited, although it suggests the precious capability of stem cells for bladder regeneration.