Silk fibroin/hydroxyapatite composites for bone tissue engineering

Silk fibroin (SF) is a natural fibrous polymer with strong potential for many biomedical applications. SF has attracted interest in the field of bone tissue engineering due to its extraordinary characteristics in terms of elasticity, flexibility, biocompatibility and biodegradability. However, low osteogenic capacity has limited applications for SF in the orthopedic arena unless suitably functionalized. Hydroxyapatite (HAp) is a well-established bioceramic with biocompatibility and appropriate for constructing orthopedic and dental substitutes. However, HAp ceramics tend to be brittle which can restrict applications in the repair of load-bearing tissues such as bones. Therefore, blending SF and HAp combines the useful properties of both materials as bone constructs for tissue engineering, the subject of this review.