仿生骨支架微观孔结构的构建与评价

Generation and Evaluation of Porous Structure of Bionic Bone Scaffold

在分析人体骨微观孔结构和影响支架性能因素的基础上,提出仿生骨支架微观孔结构的构建与评价方法。基于多约束背包问题模型的结构,以椭球体作为构建微观孔结构负模型的单元体,利用混合遗传算法求解微观孔结构的负模型;并将孔隙率和连通性作为约束条件,以保证仿生骨支架具有生物活性。通过不含微观孔的支架模型与负模型之间的布尔运算,构建含有微观孔结构的仿生骨支架模型。以支架的孔隙率、孔间的连通性、孔分布的均匀性、孔道的扭曲度和支架的比表面积作为评价指标,建立仿生骨支架微观孔结构的评价体系。基于支架微观孔结构的负模型,提出支架的孔隙率、连通性、均匀性、扭曲度和比表面积的计算方法,以实现对仿生骨支架微观孔结构的评价与优化。通过上述方法构建的仿生骨支架具有良好的生物活性、较好的力学性能以及均衡的降解速度。

According to the analysis on porous structure of human bone and factors influencing scaffold performance,the generation and evaluation method of porous structure of bionic bone scaffold is proposed.Based on the structure of multi-constrained knapsack problem model and an ellipsoid taken as the unit body,the hybrid genetic algorithm is used to solve the inverse model of porous structure.Moreover,porosity and connectivity are used as the constraint condition to ensure the bioactivity of bionic bone scaffold.The model of bionic bone scaffold with pores is generated by Boolean operation between the model of scaffold without pores and the inverse model of porous structure.The evaluation system of porous structure of bionic bone scaffold is established with five evaluation indexes,i.e.porosity of scaffold,connectivity of pore,uniformity of pore distribution,twisting degree of pore canal and specific surface area of scaffold.Based on the inverse model of porous structure of scaffold,the calculation methods of porosity,connectivity,uniformity,twisting degree and specific surface area of scaffold are proposed to evaluate and optimize the porous structure of bionic bone scaffold.The bionic bone scaffold generated with this method has good bioactivity,better mechanical properties and uniform degradation rate.