Enhanced Bladder Regeneration with Adipose-Derived Stem Cell-Seeded Silk Fibroin Scaffolds: A Comparative Analysis

Effective bladder reconstruction remains a significant challenge in urology, particularly for conditions requiring partial or complete bladder replacement. In this study, the efficacy is evaluated of two types of scaffolds, silk fibroin (SF) and adipose-derived stem cells (ADSCs-SF), in promoting bladder regeneration and their associated outcomes. A rat model was used to compare the surgical outcomes and morphological recovery of bladder tissues implanted with SF and ADSCs-SF scaffolds. Post-operative recovery, including voiding ability and complication rates, was assessed. The morphological and histological changes of the regenerated bladder tissue were evaluated at multiple time points (2, 4, 8, and 12 weeks) using gross tissue analysis, histometric assessments, and immunohistochemical staining. Both scaffold types demonstrated successful integration into the bladder wall with no significant differences in body weight or voiding issues. The SF scaffold group exhibited graft shrinkage and a 41.6% incidence of bladder calculus formation. In contrast, the ADSCs-SF scaffold facilitated superior morphological restoration, with bladder tissue progressively adopting a more normal shape and no incidence of bladder calculus. Histological analysis revealed that the ADSCs-SF scaffold significantly promoted the regeneration of a more organized urothelium layer and smooth muscle tissue. It also resulted in higher vessel density and reduced infiltration of inflammatory cells when compared to the SF scaffold alone. Additionally, the ADSCs-SF group exhibited enhanced expression of key markers, including uroplakin III, a urothelial marker, and α-SMA, a smooth muscle cell marker. These findings suggest that the ADSCs-SF scaffold not only supports the structural integrity of the bladder but also improves tissue regeneration and reduces adverse inflammatory responses, offering a promising approach for bladder repair and reconstruction.