Scaffold-bone Integration Model And Scaffold Design Based On Lattice Boltzmann Method

The bone defect is one of the important causes of clinical loss of function and quality of life.Surgical implantation of porous bone scaffolds is an important clinical tool for the treatment of bone defects.The structural design of porous bone scaffolds depends on a thorough understanding of the bone regeneration process.However,due to the complex physiological processes involved in bone regeneration in porous bone scaffolds such as inflammatory response,cell migration and differentiation,and angiogenesis,it is difficult for biological experiments to describe this process systematically and completely.Bone regeneration models provide a means of quantitative analysis to probe biological processes,which cannot be resolved in biological experiments and contribute to the structural design of personalized porous bone scaffolds.A continuous-discrete model was developed,which used the mathematical formula to describe the ingrowth process of bone in porous implants,including cell activity,vascular network formation and material diffusion.The model can more visually simulate the physiological processes that occur inside the porous scaffold after the scaffold is implanted at the site of bone injury and predict the distribution of bone deposition.What’s more,in this paper,the bone regeneration model based on the lattice Boltzmann equation is implemented on the GPU platform to solve the increasing scale of simulation operation and operation time brought by the scales of scaffolds and the complexity of structures.It is shown that the GPU-based model has more than 6 times increase in computing speed over the CPU-based model.The prediction of bone deposition distribution is consistent with the staining results of biological experiments,which indicates that the simulation model can be used to explore the growth process of bone within the porous scaffold.Additionally,several parameters of porous scaffold design that affect bone regeneration results were explored.It is demonstrated that the curvature of the porous scaffold will alter the permeability of the scaffold,which will affect the distribution of blood vessels and eventually change the distribution of bone deposition within the porous scaffold as well as the total amount of bone deposition.The change in pore size affects the distribution of bone,and a highly connected pore structure can enhance the degree of bone tissue binding to the porous scaffold.Finally,the mechanical properties of the predicted scaffold-bone integration structure are analyzed.The study shows the spiral porous structure has a better stress distribution performance during the initial implantation.The push-out test illustrates that the spiral structure can enhance the bonding between the porous scaffold and the bone.This conclusion contributes to the design of a better porous scaffold structure.