Recently, the Root and Tuber Crops Food Science and Technology Innovation Team of Food Science and Technology Institute, Chinese Academy of Agricultural Sciences (IFST-CAAS) investigated a novel bone tissue engineering scaffold with uniform pore size and good cell adhesion, which can be used for repairing large bone defects. This work was published in the top journal "International Journal of Biological Macromolecules" (JCR Q1, IF=7.7). Professor Hongnan Sun and Taihua Mu are the corresponding authors and the GSCAAS-LGg program PhD student Shunshun Zhu is the first author. The research was financially supported by the earmarked fund for CARS (CARS-10), and the Science and Technology Innovation Project of the Chinese Academy of Agricultural Sciences.

Bone tissue engineering scaffolds were becoming an ideal strategy to replace autologous bone grafts for surgical bone repair, but due to the lack of suitable biomaterials, there was still a lack of effective means to promote regenerated bone to achieve the superior performance of natural bone. Therefore, there was still an urgent need to develop novel bio scaffolds to facilitate bone injury repair.

In this study, the preparation process of alkylation-modified cellulose nanocrystals dispersants (K-PCNCs) was optimized by analyzing the effects of ultrasonic time (0-3 h), and ultrasonic power (400-500 W) on the water contact angle and degree of substitution, and nanohydroxyapatite (HC-K) was synthesized using K-PCNCs as a dispersant. Then, HC-K was compounded with polyvinyl alcohol (PVA) to prepare composite bio scaffolds using the ice template method. The results showed that the highest water contact angle and degree of substitution (135°, 1.53) of K-PCNCs were obtained when the ultrasonic power was 450 W and the time was 2 h. The obtained K-PCNCs had a rod-like structure with a diameter range of 28-35 nm and a length range of 100-250 nm and possessed the highest absolute ζ potential, thermal properties, crystallinity, and dispersion properties, which could be used as dispersants for HC-K. The porosity, equilibrium swelling rate, and mechanical properties of the composite scaffolds increased and then decreased with increasing HC-K content, reaching the maximum values (56.1%, 807.7%, and 0.085 MPa) at 9% (w/w) HC-K content. Cellular experiments showed that the scaffolds had good cytocompatibility and osteogenic mineralization capacity, promoting osteoblast proliferation and adhesion within 10 days and high alkaline phosphatase levels within 14 days.

This study clarified the in vitro osteogenic ability of bone tissue engineering scaffolds, which was of great significance in promoting the clinical application of bone tissue engineering scaffolds in bone defect repair. It also helps to research the innovative application of cellulose nanocrystals in the field of bone defect repair and provides data support and theoretical reference for the development of novel bone tissue scaffolds.

Link：https://doi.org/10.1016/j.ijbiomac.2024.135571

Diagram of the mechanism underlying the formation of the bone tissue engineering scaffold