Assessment of α-calcium sulfate hemihydrate/nanocellulose composite bone graft material for bone healing in a rabbit femoral condyle model

The material properties of nanocellulose (NC) can effectively enhance the structural stability of composite materials. However, the research related to NC/α-calcium sulfate hemihydrate (CSH) composites is largely lacking. In this paper, we explore the combination of these two materials and determine their elaborate biological activities in vivo. Using α-CSH as the matrix, the composite bone graft materials were produced according to different proportions of NC. Then the mechanical strength of the composite bone graft was measured, and the results were analyzed by X-ray diffraction and scanning electron microscopy (SEM). To conduct the material in vivo evaluation, 0% (CN0) and 0.75% (CN0.75) NC/α-CSH composite bone graft materials were implanted into a femoral condyle defect model. The results indicated that NC could significantly enhance the mechanical properties of α-CSH. The SEM analysis indicated that the NC shuttled between the crystal gaps and formed a three-dimensional network structure, which was firmly combined with the crystal structure. Meanwhile, the CN0.75 scaffold remained at 12 weeks postoperation, which provided a long-term framework for new bone formation. Overall, our findings demonstrate that, with a 0.75% NC/α-CSH composite demonstrating good potential as a bone graft material for clinical bone grafting.