Engineering the Future of Bladder Repair: Can Biocompatible 3D-Printed Scaffolds Serve as a Novel Alternative to Intestinal Segments for the Treatment of Bladder Exstrophy?

Background: Bladder reconstruction traditionally involves intestinal segments, which, despite their effectiveness, carry significant risks such as metabolic disturbances and infection. Safer, synthetic alternatives are needed. We evaluated a novel 3D-printed multilayered bladder scaffold combining polylactic acid (PLA), thermoplastic polyurethane (TPU), and polyvinyl alcohol (PVA) in a rabbit model. Methods: Anatomically tailored scaffolds were designed using computer-aided design (CAD) and fabricated under good manufacturing practice (GMP) conditions. Mechanical integrity was assessed after 60 days of incubation in simulated bladder media, including measurements of modulus of elasticity, tensile strength, elongation, and shape recovery. Acid/alkaline resistance was tested for chemical stability. For in vivo analysis, four rabbits underwent bladder augmentation with a 1 × 1 cm scaffold-augmented defect. Postoperative outcomes were monitored for 60 days, followed by histopathological evaluation. Results: After incubation, the scaffolds retained mechanical strength (modulus: 1.2 ± 0.3 GPa; tensile strength: 18.5 ± 2.1 MPa) with minimal elongation reduction (25% vs. 28% unused). Chemical testing confirmed structural stability and full shape recovery. In vivo, all rabbits survived without urinary leakage. Mild intra-abdominal adhesions and universal cystolithiasis were noted. Histology showed complete urothelial reepithelialization and mild-to-moderate submucosal fibrosis with chronic inflammation but no necrosis or acute inflammation. Compared to biological scaffolds, the synthetic construct showed reduced mortality and comparable inflammation, though with increased stone formation. Conclusion: This 3D-printed scaffold demonstrates promising biocompatibility, mechanical durability, and integration in bladder repair. While early results are encouraging, further studies with larger sample sizes and longer follow-up are needed to address limitations such as cystolithiasis risk.