A Bilayered Electrospun Vascular Graft Enabling Differentiation of Adipose Derived Mesenchymal Stem Cells Toward Smooth Muscle Lineage

ABSTRACT The successful engineering of vascular grafts that promote contractile SMC differentiation relies on a multifaceted approach that includes the selection of appropriate cell sources, materials, and environmental cues. The integration of insights from molecular regulation, stem cell biology, and material science is essential for advancing the field of vascular tissue engineering. In this study, a bilayered vascular graft was produced using the electrospinning technique. The electrospun inner layer is composed of polyvinyl alcohol co‐ethylene, which provides mechanical stability, and the outer layer is a blend composition of gelatin vinyl acetate copolymer and polycaprolactone, which provides a microenvironment for cell growth. Morphological analysis, wall thickness, and fiber diameter measurements were performed using scanning electron microscopy. Mechanical properties, fluid uptake, and degradation studies were assessed for both mono‐ and bilayer scaffolds. The findings revealed that the bilayered samples exhibited an ultimate stress, Young's modulus, and suture retention of 1.98 ± 0.15 MPa, 46.53 ± 5.3 MPa, and1.19 ± 0.58 N, respectively. Furthermore, the bilayered grafts demonstrated good cytocompatibility. The study also explores the use of all‐trans retinoic acid to initiate the differentiation of sheep adipose‐derived mesenchymal stem cells cultured on the 3D bilayered scaffold system toward smooth muscle lineage via a two‐step induction protocol. The differentiation was assessed by immunostaining for the specific markers SMA, calponin, and SM22α. The bilayered scaffold was shown to possess similar mechanical strength as native tissue and provided an ideal matrix for stem cell differentiation to smooth muscle cells and promoted vascular reconstruction.