The fabrication of 3D surface scaffold of collagen/poly (L-lactide-co-caprolactone) with dynamic liquid system and its application in urinary incontinence treatment as a tissue engineered sub-urethral sling: In vitro and in vivo study.

AIMS: To fabricate a novel nanoyarn biomaterial via a dynamic liquid electrospinning system, and to simultaneously evaluate whether nanoyarn is capable of being applied as a urinary sling for future clinical transfer.

METHODS: Nanoyarn was cultured with adipose-derived stem cells (ADSCs). Cell morphology and function were observed on nanoyarn. Female rats that underwent vagina dilatation (VD) and bilateral ovarian resection (BOR) were used as the urinary incontinence model. After 2 weeks, the cells-sling was fixed to the suburethra. A commercial sling that tension-free vaginal tape-obturator (TVT-O) was used as a control. The urodynamic test for leak point pressure (LPP) and histological tests were used to evaluate the sling's performance in vivo.

RESULTS: The nanoyarn possessed beneficial properties and the actin filament from ADSCs, which is very similar to muscle. Rats that underwent VD and BOR maintained a low LPP, whereas the LPP in rats with VD alone recovered to normal levels within 2 weeks. LPP in the nanoyarn group gradually decreased on the three urodynamic tests post-suburethral surgery, however, the cell-laden nanoyarn maintained LPP at normal levels for 8 weeks; the TVT-O group showed a significant increase in LPP at 8 weeks. Cell-laden nanoyarn was infiltrated with more cells, collagen, and vessels than the controls.

CONCLUSIONS: The nanoyarn showed sufficient efficacy to maintain LPP in urinary incontinence rat model. In addition, it improved cell infiltration, collagen and muscle development compared to TVT-O. Thus, the combination of ADSCs and a nanoyarn scaffold could be a promising tissue-engineered sling for the treatment of urinary incontinence.