Three-dimensional silk impregnated HAp/PHBV nanofibrous scaffolds for bone regeneration

ABSTRACT

Three-dimensional silk fibroin impregnated poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofibrous scaffolds with or without hydroxyapatite (HAp) were prepared by wet-electrospinning method followed by freeze-drying. Scaffolds with cotton wool-like structure have the average fiber diameter of 450–850 nm with 80–85% porosity. In-vitro cell culture tests using MG-63 osteosarcoma human cells revealed improved cell viability, alkaline phosphatase (ALP) activity and total cellular protein amount on the silk impregnated scaffolds compared to PHBV and HAp/PHBV scaffolds after 10 days of cell culture. Immunohistochemical analyses on the silk impregnated scaffolds showed that HAp triggered cell penetration and type I collagen production. Besides, HAp mineralization tendency increased with a decrease in percent crystallinity of the scaffolds comprising HAp and silk after 4 weeks of incubation in simulated body fluid. Consequently, cotton wool-like HAp/PHBV-SF scaffold would be a promising candidate as a bone-filling material for tissue regeneration.

GRAPHICAL ABSTRACT

KEYWORDS:

• Bone tissue engineering
• hydroxyapatite
• PHBV
• silk fibroin
• wet-electrospinning

Acknowledgments

The authors would like to thank the Izmir Institute of Technology Biotechnology and Bioengineering Research and Application Center for the freeze-drying studies and METU Central Laboratory for the porosity measurement. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.