Mechanical Characterisation of Carbonised Plant Scaffolds as Potential Bone Graft Substitutes

This article presents an assessment of the mechanical properties of biochars in the context of their potential application as bone graft substitutes. The samples were obtained from selected hardwood species and subjected to pyrolysis at temperatures of 400 °C, 600 °C, 800 °C and 1000 °C. To assess the mechanical properties, a classical three-point bending test was employed alongside Digital Image Correlation (DIC), which enabled analysis of displacement and strain distribution. The results indicate that biochars derived from hornbeam pyrolysed (carbonised) at 800 °C achieve Young’s modulus values of up to 5.69 ± 0.76 GPa and those, carbonised at 1000 °C, reached flexural (bend) strength values of up to 0.01897 ± 0.00211 GPa. These parameters fall within the range of cancellous bone properties and the lower range of cortical bone properties of the mandible, suggesting their potential suitability for reconstructing load-bearing bone structures with limited mechanical demand, including the mandible. The results highlight the effect of pyrolysis temperature on the microstructure and mechanical properties of the material and indicate the need for further studies on biocompatibility and surface functionalisation. Plant-derived biochars, owing to their natural porosity and properties comparable to bone tissue, may represent a promising alternative to currently used biomaterials in bone tissue engineering.