31^st Materials Science and Engineering Conference: Advancement & Innovations

In this research work novel 3D scaffold for bone tissue engineering have been produced, characterized and tested using an integrated bio-engineering approach, applying bio-mechanical stimuli generated by a Pulsed Electro-Magnetic Field (PEMF). Keratin 3D scaffolds, namely wool fibril sponges, were prepared by ultrasonic irradiation of wool fibers soaked in clean water, previously swollen in mild alkali. Casting the fibrils suspension produced microporous, biocomposite sponges, made of randomly oriented cortical cells stuck to each other by the hydrolyzed keratin matrix. Nevertheless, controlled-size salt-leaching allowed an additional 3D-tailored macroporosity, with the aim of matching native bone features for cell proliferation and cell guided tissue formation. Sponges have been characterized for morphology, amino acid composition, thermal and mechanical behaviour and in vitro ageing performances. In addition, osteoblast cell model (SAOS-2) was cultured onto 3D wool fibril sponge using an integrated bio-engineering approach, applying bio-mechanical stimuli of a PEMF. Mechanical properties of the wool fibril sponges come out in favour of promising applications as a bio-absorbable scaffold for bone tissue engineering since they are easy to handle and resilient in wet conditions. The integrated bio-engineering approach of applying bio-mechanical stimulus from PEMF, in addition to 3D architectural stimulus is given by 3D scaffolds, showed to be a successful solution. In fact, PEMF stimulated an earlier differentiation in osteogenic conditions, showing a perfect synergy between biochemical and mechanical stimuli in the acceleration of the differentiation process. Finally, ageing tests revealed that wool fibril sponges, characterized by an exceptional amount of crosslinks that stabilize the keratin structure, are surpassingly stable, showing longer degradation rate compared to commercial collagen. In conclusion, biological, chemico-physical characterization and ageing tests suggest sponges are promising candidate for long term support of in vivo bone formation.