Development of a complex bone tissue culture system based on cellulose nanowhisker mechanical strain

In bone tissue engineering, scaffolds have been investigated for their ability to support osteoblast growth and differentiation for recovery of damaged bones. Tunicate cellulose nanowhisker (CNW) film and mechanical strain were assessed for their suitability for osteoblasts. In this study, sulfuric acid hydrolysis extraction of tunicates integuments was conducted to obtain CNWs, which were found to be acceptable for adhering, growing, and differentiating osteoblasts without cytotoxicity. Mechanical stress enhanced osteoblast differentiation, and cell survival rate was recovered at around day 3, although there was a slight increase in cell death at day 1 after stimulation. We also found that intracellular flux of calcium ion was related to increased differentiation of CNWs under mechanical stress. Overall, we demonstrated the suitability of tunicate CNWs as a scaffold for bone tissue engineering and developed a complex system based on CNW for osteoblast growth and differentiation that will be useful for bone substitute fabrication.