Human Amniotic Fluid Stem Cell-mediated Biomechanical Restoration of Urinary Continence in Rats

Stress urinary incontinence (SUI) adversely impacts millions worldwide due to weakened pelvic floor muscles and urethral sphincter dysfunction. To date, there is a lack of effective non-surgical treatment for SUI, and no clear consensus has been reached on the optimal stem cell source under regenerative therapy. Existing studies have shown no precise molecular mechanisms underlying stem cell-mediated external urethral sphincter (EUS) regeneration. Therefore, we investigated the regenerative and reparative potential of our clinical-grade human amniotic fluid stem cells (hAFSCs) for treating SUI.

We determined the immunophenotype, multi-differentiation potential, and secretome of AFSCs. Treated animals were grouped into sham, UI, phosphate buffer saline, and hAFSC groups. Pudendal nerve injury was created to induce SUI in female rats and treated with hAFSCs by administering them into the external urethral sphincter.

Isolated AFSCs showed trilineage potential and expressed neuronal-specific markers such as Nestin, Tuj-1, MAP2, and GFAP. hAFSCs-treated group showed significantly (p < 0.01) improved leak point pressure, intercontractile interval, and total muscle cell proliferation numbers. hAFSCs showed elevated levels of VEGF, IL-8, TIMP-1, and TIMP-2. Histological assessment of bladder tissues reveals that hFASCS ameliorated lower ulceration and edema. Immunofluorescence staining and myogenic differentiation markers, i.e., Myf5, Myogenin, and MyoD, indicate the bladder tissue regenerating potential of hAFSCs. No hAFSC trafficking was observed in other tissues and organs.

These findings highlight hAFSCs' potential as a novel therapy for SUI, warranting more extensive clinical trials to optimize dosing and long-term efficacy while addressing scalability and safety challenges in translating this regenerative approach to clinical practice.