Modeling osteoinduction in titanium bone scaffold with a representative channel structure
Siyuan He, Yun Zhang, Yin Zhou, Nirong Bao, Yan Cai, Ping Zhou, Peng Wang, Lan Li, Qing Jiang
Abstract
Optimizing scaffold architecture for perfect osteointegration depends on good understanding of bone ingrowth in the porous space of implants. This study developed an immunoregulatory agent-based model to discover the osteoinduction mechanism in porous scaffolds. Immunoreaction, macrophage polarization, and the corresponding growth factors were combined in the model, and all played critical roles in recruiting osteogenic cells that migrated into the scaffolds. Angiogenesis was also considered in this model. The bone ingrowth predicted by the model coincides with results from published in vivo experiments. Simulation results suggested that the pore architecture affected the diffusion process of chemotactic factors in the scaffolds, subsequently influencing the complex reactions of diverse cells and the osteoinduction location. In flexural pore spaces, bone formation spread from the periphery into the center of scaffolds due to larger M2 phenotype macrophage populations colonizing boundary regions and the distribution of corresponding growth factors concentration. In straight channels, osteogenic cells migrated further inward and osteoinduction initiated in deeper position as a result of the deeper distribution of osteogenic cytokines concentration field. • An immuneragulatory numerical model is developed to predict osteogenesis in scaffold. • Angiogenesis was considered in this model. • Different polarized macrophages produce gradients of chemical signals. • Pore architecture influences osteogenesis by changing diffusion field in scaffold. • Osteoinduction in straight channels initiated deeper than flexural porous space.