Sugarcane Stem Derived Hybrid Scaffold for Bone Tissue Engineering via Top-down Approach

A novel bone tissue engineering material with a merit of good biocompatibility and excellent mechanical properties was fabricated with a top-down method. In this work, sugarcane was first treated in NaClO2/acetate buffer to remove lignin, i.e. delignification, and the effect of delignification on pore size of sugarcane is explored bby varying the soaking time in the buffer. Results show that 4 h is the optimal delignification time to ensure good mechanical properties of the sugarcane. The subsequent surface modification with alendronate trihydrate has an advantage to facilitate the final deposition of hydroxyapatite (HAp) due to the fact that the introduction of phosphate groups can effectively improve the nucleation efficiency of HAp. We found that the deposited HAp on sugarcane stem templates can form a bioactive hybrid scaffold material with a hierachical pore structure. Fortunately, during the delignification process of the cellulose structure in the sugarcane stem is not destroyed, thus the hierarchical pore structure remains. The final obtained hybrid scaffold presents a three-dimensional anisotropic porous structure and its longitudinal strength is much higher than the radial strength. The anisotropic property can provide a good mechanical support for scaffold applications. Moreover, the CCK-8 test shows that the cell viability is higher than 95%, indicating that the scaffold exhibits no cytotoxicity. Our investigation demonstrates that the presented hybrid scaffold derived from sugarcane stem has a great potential in the application of bone tissue engineering.