Ureter tissue engineering with vessel extracellular matrix and differentiated urine-derived stem cells

Area of Science:

• Regenerative Medicine
• Biomaterials Science
• Stem Cell Biology

Background:

• Urinary tract reconstruction presents challenges, particularly for long-segment defects.
• Tissue engineering offers a promising alternative to traditional reconstructive methods.
• Vessel extracellular matrix (VECM) and urine-derived stem cells (USCs) are potential building blocks for engineered tissues.

Purpose of the Study:

• To evaluate the feasibility of ureter tissue engineering using VECM and differentiated USCs in a rabbit model.
• To develop a novel strategy for creating functional ureter grafts.
• To assess the in vivo performance of engineered ureter constructs.

Main Methods:

• VECM was prepared using a modified technique and characterized for biocompatibility and vascularization potential.
• Human USCs were isolated and differentiated into urothelial and contractile smooth muscle cells in vitro.
• Differentiated USCs were seeded onto VECM, cultured dynamically, and matured with omental wrapping for vascularization.
• Engineered grafts were used for ureter reconstruction in vivo in a rabbit model.

Main Results:

• VECM demonstrated microporous structures, cell infiltration support, and biocompatibility.
• Differentiated USCs expressed urothelial and functional contractile smooth muscle phenotypes.
• Engineered grafts showed vascularization after 3 weeks of omental maturation.
• Histological analysis at 2 months post-reconstruction revealed a well-structured ureter with multilayered urothelium and organized smooth muscle.

Conclusions:

• Seeding differentiated USCs onto VECM creates a tissue-engineered graft capable of forming functional ureter tissue in vivo.
• This novel strategy shows potential for treating long-segment ureteral defects.
• The combination of VECM and USCs represents a viable approach for ureter tissue engineering.