Fabrication of Nanofibrous PVA/Alginate-Sulfate Substrates for Growth Factor Delivery.

Providing affinity sites on alginate (ALG) matrix enables specific binding of growth factors to the polymer backbone and allows their release in a controlled fashion. In this study, we used a blend of alginate sulfate (ALG-S) and polyvinyl alcohol (PVA) to fabricate electrospun scaffolds capable of delivering a heparin-like growth factor, transforming growth factor-beta1 (TGF-β1). The alginate was sulfated with different degrees of sulfation (DS, from 0.8, 3.4 to 12.4%) by a simple process. The success of sulfation was determined by Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), elemental analysis, ultraviolet (UV) spectroscopy and staining with dimethylmethylene blue. The physical-mechanical properties of nanofibrous mats were characterized by scanning electron microscopy (SEM), FTIR, energy-dispersive X-ray spectroscopy (EDX), tensile strength and mass loss analysis. Additionally, the release kinetics of transforming growth factor-β1 (TGF-β1) from PVA/ALG-S and PVA/ALG scaffolds were compared. The results showed that the binding and entrapment of TGF-β1 to the nanofibrous scaffolds are improved by the addition of sulfate group to alginate. In conclusion, our results support that nanofibrous scaffold based on PVA/ALG-S can deliver growth factors in tissue engineering application. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 403-413, 2019.