Enhancement of mechanical properties of silk scaffolds by reinforcement with silk micro particles

Introduction Scaffolds fabricated from silk have shown good osteoinduction. However, the mechanical properties were insufficient to match native bone. We previously investigated the effects of mineral incorporation (by coating as well as embedding into the silk phase) as a method to enhance mechanical properties of porous silk scaffolds for bone tissue engineering. Based on encouraging results of these recent studies, we now investigated if the enhancement of mechanical properties can be achieved by using an all-silk scaffold. We systematically investigated two modifications of silk scaffolds with respect to human stem cell differentiation and the development of engineered bone: (i) increase in scaffold stiffness by altering silk fibroin concentration (resulting in a smooth, single phase porous scaffold) and (ii) reinforcement by embedding silk microparticles (resulting in two-phase porous scaffolds with strong interfacial compatibility and surface roughness).