Electrospun nanoyarn seeded with myoblasts induced from placental stem cells for the application of stress urinary incontinence sling: An in vitro study.

OBJECTIVE: To fabricate a novel electrospun nanoyarn using dynamic liquid electrospinning technique. The nanoyarn will be seeded with myoblasts differentiated from placental stem cells (PSCs) to evaluate the feasiblity of the cell-scaffold construct as a tissue engineering sling to treat stress urinary incontinence.

MATERIAL AND METHODS: PSCs were induced to myoblasts with 5-azacytidine and horse serum. Myoblasts differentiation was confirmed by immunofluorescence and western blot. Western blot was also used to assess the change of extracellular matrix (ECM) expression. A dynamic liquid electrospinning system was used to fabricate a novel nanoyarn scaffold for myoblast seeding. Cell morphology and proliferation on nanoyarn and nanofiber scaffold were compared with scanning electron microscopy (SEM) and MTS assay respectively. Filament actin development was tested with Rhodamine-labeled phalloidin stainning; cell infiltration into scaffolds was observed with H&E stainning. ECM expression was evaluated by a collagen assay, immunofluorescence imaging and real-time PCR.

RESULTS: Myoblasts showed increased expression of α-SMA, desmin, and collagen type 1, 3 when compared to PSCs. The nanoyarn possessed higher porosity, larger pore size, and aligned fibers/yarns as compared to nanofiber scaffold. Cell proliferation was significantly improved on nanoyarn scaffold. Cells could infiltrate deeply in the nanoyarn scaffold after 7 days in culture, however, they could only proliferate on the surface of the nanofiber scaffold. The myoblast-nanoyarn constructs seemed to be more like a muscle tissue. The myoblasts spreading on the nanoyarn scaffold were visible with aligned actin filaments in the horizontal view, whereas myoblasts spreading on the nanofiber scaffold were visible with unaligned actin filaments. Nanoyarn myoblasts exhibited higher production and density of type 1, 3 collagen and elastin.

CONCLUSIONS: PSCs could be induced into myoblast and expressed elevated myogenic markers and ECM. PSCs are potential cell source for a tissue engineered sling. The novel electrospun nanoyarn scaffold showed potential for use as a sling for treatment of stress urinary incontinence. In vitro studies demonstrated that the nanoyarn scaffold could improve cell proliferation, muscular tissue development, and ECM expression compared to random nanofiber scaffolds. The combination of myoblasts and nanoyarn scaffold could be a promising tissue engineered sling for future in vivo studies.