Aligned silk fibroin/poly-3-hydroxybutyrate nanofibrous scaffolds seeded with adipose-derived stem cells for tendon tissue engineering

In this work we investigated tenogenic differentiation of adipose-derived mesenchymal stem cells (AdMSCs), which were seeded onto silk fibroin/poly-3-hydroxybutyrate (SF/P3HB) scaffolds with aligned topography, and high mechanical strength. The electrospinning process was optimized by using the response surface method (RSM) and SF/P3HB nanofibrous matrices with a total polymer concentration of 5% (SF: PHB = 3: 1), flow rate 1 mL/h, collector rotation speed 2000 rpm, applied voltage 14 kV, and collector distance 25 cm were obtained. The average fiber diameter was 699 ± 203 nm and 80% of the nanofibers were aligned within the ±15^o range. SF reinforcement reduced the crystallinity of P3HB, and the elastic modulus was found to be 197.0 ± 7.7 MPa. The scaffolds showed bacteriostatic effect. A 21-day of cell culture study was performed with rat rAdMSCs in the absence and presence of tenogenic differentiation factor-5 (GDF-5). The results demonstrated that SF/P3HB scaffolds allow the cells to proliferate and differentiate to the tenocytes. However, no significant effect of GDF-5 on the differentiation of cells was observed. These findings indicated that our aligned SF/P3HB scaffolds have a significant potential to be used for tendon tissue engineering.