Polycaprolactone-co-polylactic acid nanofiber scaffold in combination with 5-azacytidine and transforming growth factor-β to induce cardiomyocyte differentiation of adipose-derived mesenchymal stem cells.

Adipose-derived mesenchymal stem cells (Ad-MSCs) are promising candidates for cardiac repair/regeneration. The application of copolymer nanoscaffolds has received great attention in tissue engineering to support differentiation and functional tissue organization toward effective tissue regeneration. The objective of the current study was to develop functional and bioactive scaffolds by combining polycaprolactone (PCL) and polylactic acid (PLA) for cardiomyocyte differentiation of human Ad-MSC (hAd-MSCs) in the absence or presence of 5-azacytidine and transforming growth factor-β (TGF-β). To that end, the human MSCs were extracted from human adipose tissue (AD). The cardiomyocyte differentiation potency of hAd-MSCs was evaluated on the novel synthetic PCL/PLA nanofiber scaffolds prepared in the absence and presence of 5-azacytidine and TGF-β supplements. A PCL/PLA nanofibrous scaffold was fabricated using the electrospinning method and its nanotopography and porous structure were characterized using scanning electron microscopy. In addition, the attachment of hAd-MSCs on the PCL/PLA scaffolds was semiquantitatively investigated. Compared with other treatments, the PCL/PLA nanofibrous scaffold supplemented with both 5-azacytidine and TGF-β was observed to differentiate hAd-MSCs into cardiomyocytes at Day 21 as evidenced by real-time PCR for cardiac-specific genes including cardiac troponin I (cTnI), GATA4, MYH7, and NKX2.5. In addition, flow cytometric analysis of cTnI-positive cells demonstrated that the cardiomyocyte differentiation of hAd-MSCs was more efficient on the PCL/PLA nanofibrous scaffold supplemented with both 5-azacytidine and TGF-β than it was in the other treatment groups. Generally speaking, the results show that PCL/PLA nanofibrous scaffolds may be applied as a platform for efficient differentiation of hAd-MSCs into functional cardiomyocytes.