iBone: A Reaction Diffusion Based Shape Optimization Method

• Published in: Key engineering materials 2003-01, Vol.243-244, p.601-606
• Main Authors: Wada, Yoshitaka, Kikuchi, Masanori, Tezuka, Ken-Ichi
• Format: Article
• Language: English
• ISSN: 1013-9826; 1662-9795; 1662-9795
• DOI: 10.4028/www.scientific.net/KEM.243-244.601

Bone is a highly specialized form of connective tissue consisting of organic and inorganic materials. Bone is continuously remodeled by bone forming osteoblasts and resorbing osteoclasts. In terrestrial vertebrates, these two activities are strictly balanced and adapt the shape of bone to the local stress with limited calcium intake from foods. However, the cell based-adaptation mechanism underlying this system have not been well considered. Recently, we have found that human mesenchymal stem cells strongly stimulated towards osteoblastic lineage form a condensation pattern similar to Turing patterns observed in reaction-diffusion models. We constructed a hypothetical model of bone remodeling (iBone), by coupling the bone forming and resorbing activities based on the reaction-diffusion model weighed by local stress. When an external mechanical stress was applied to a sample model, stimulated bone formation and subsequent activation of bone resorption efficiently adapted the shape of it to the given stress, and created flat stress distribution. iBone could also repair fractures which caused uneven stress distribution. The efficacy of iBone proposes a principal model how bone cells can form a cooperative system that adapt the microstructure of bone to the voluntary mechanical loads; and, suggests that element based-parallel computing system, such as reaction-diffusion system, can be applied for designing efficient stress adaptation models.