A novel integrated biphasic silk fibroin scaffold for intervertebral disc tissue engineering

The intervertebral disc (IVD) tissue engineering construct provides a promising approach for the treatment of symptomatic degenerative disc diseases. In this study, a novel 3D silk fibroin biphasic scaffold for integrated IVD tissue engineering was fabricated by sequentially using the paraffin sphere-leaching method for annulus fibrosus (AF) phase and the phase separation method for nucleus pulposus (NP) phase. Both phases were perfectly integrated and possessed a highly interconnected porous structure with pore size of 220±23.1 μm for AF and 90±17.8 μm for NP phase. Furthermore, the scaffolds were found to have a high porosity of 91% and 93% for AF and NP phases, respectively. In addition, this silk biphasic scaffold had a relative high compressive modulus under wet conditions (150.7±6.8 kPa). Rabbit AF and NP cells could attach, grow and further penetrate into the scaffold and distribute uniformly. This silk fibroin biphasic IVD scaffold emerges as a potential candidate for IVD tissue engineering.