Comparative study of bladder augmentation using different biomimetic scaffolds: electrospun nanofiber vs. extracellular matrix scaffold with adipose-derived stem cells.

BACKGROUND

Bladder augmentation with gastrointestinal segments is a widely used surgical procedure for neurogenic bladder, but it carries a risk of many side effects. However, there have been no systematic studies on which biomaterials are suitable for bladder augmentation and reconstruction. The aim of this study was to compare the safety and applicability of small intestinal submucosa (SIS), poly(l-lactic) acid (PLLA) nanofibrous scaffold, and PLLA/gelatin composite nanofibrous scaffold as a potential bladder wall substitute material in tissue-engineered bladder augmentation and reconstruction. The results provide a scientific basis for selecting appropriate materials in clinical applications.

MATERIALS AND METHODS

The microstructure, cytocompatibility, cell adhesion, and histocompatibility of scaffolds including SIS, PLLA nanofiber scaffold, and PLLA/Gelatin were observed. Furthermore, bladder augmentation rabbit models were constructed using scaffolds with and without adipose-derived stem cells (ASCs) implantation. Cystography and urodynamic examination were performed to evaluate the morphology and function of the reconstructed bladder. Histologic and immunofluorescence were used to assess the regeneration status of the reconstructed bladder.

RESULTS

Compared to SIS and PLLA/Gelatin scaffolds, the PLLA scaffold possessed appropriate mechanical properties, pore size and porosity, which could facilitate suturing, maintain bladder form, and promote the adhesion and proliferation of seeded ASCs. All animals survived in the experiment with no complications, and the structural integrity of the implantation site was demonstrated using cystography and urodynamics. Histological and immunohistochemical analyses indicated that the three kinds of scaffold could regenerate the bladder wall structure at 6 and 12 weeks. Bladder reconstructed with the ASCs-PLLA scaffold showed superior structural and functional properties, with no significant differences in the regenerated urothelium, smooth muscle, or vessels of the ASCs-PLLA and control groups.

CONCLUSION

The ASCs-PLLA scaffold-composed of PLLA with favorable biological properties and ASCs with facilitating regeneration-presents a promising candidate as an ideal scaffold for bladder augmentation and reconstruction.