Freeze-casted keratin matrix as an organic binder to integrate HA and BMP2 for enhanced cranial bone regeneration.

An ideal bone regenerative scaffold is expected to possess architectural characteristics which mimic the bone tissue, osteoconductive property and osteoinductive functionality. Key challenges to creating a scaffold with these ideal characteristics simultaneously is the selection of appropriate processing method and biocompatible materials. Herein, human hair keratin is proposed as an organic binder for the simultaneous incorporation of bone's major inorganic component, hydroxyapatite and bone's growth factor, rhBMP2 to enable both osteoconductive and osteoinductive characteristics in the creation of bone scaffolds. Besides, freeze-casting method is selected to fabricate this rhBMP2-incorporated keratin/hydroxyapatite (KHA) scaffold with aligned lamellar pores to guide and promote bone regeneration. The aligned KHA scaffolds displayed better mechanical properties, sustained rhBMP2 release, good cell compliance and 3D cellular infiltration. Implantation of KHA scaffolds in vivo revealed that scaffolds with aligned pores effectively accelerate the healing process of bone defects compared to scaffolds with random pores. This work indicates the distinctive potential of freeze casted rhBMP-2 incorporated KHA scaffolds for bone regeneration. This article is protected by copyright. All rights reserved.