Parametric Design And Fabrication For Vascular Scaffold Of Tissue Engineering Skull

Due to lack of the vascular structure in tissue engineering scaffold,the cells growth and bone formation are limited.Therefore,the vascular structure is a key issue for tissue engineering scafold design.Aimed at this problem,based on the characteristics of human skull diploic vein,a parametric design method and fabrication process were presented.Firstly,through micro CT,and its a nature skull sample was scanned and its diploic vein structure was reconstructed.Using the binary tree model,a parametric model of vascular scaffold was proposed.The centerline of the vessel was described by the binary tree structure,and the vascular segment was described by a gradient circular crosssection along the axis.According to the measurement and analysis of the reconstructed venous model,the parameter values of the parametric model was generalized.Secondly,based on the parametric model of vascular scaffold,the binary tree structure was generated by writing Matlab algorithm.The vascular segment surface was modeled by curve fitting and surface sweeping.Using MFC / ACIS / HOOPS platform,the 3D vascular scaffold design was realized.And three different vascular scaffold cases with different parameters were presented.According to the venous blood flow characters of human body,one way fluid-structure coupling finite element model of the main blood vessels and a small segment were established,the effects of flow blood on the elastic vascular structure were analyzed,the rationality of the design model was verified.Finally,SA/PVA composite hydrogel was used as the scaffold material.Through the analysis of the optimum elastic modulus and porosity by orthogonal experimental design,the optimal proportion of scaffold material was determined.A fabrication process of spray coating and lost foam cast for the vascular scaffold was proposed.Using cane-sugar as mold core material,the composite hydrogel was atomized and sprayed to the core surface.Taking advantages of the porosity and hydrophilicity of the hydrogel,the cane-sugar core was exuded in deionized water at room temperature.Then the vascular scaffold was fabricated,its inner diameter is about 1mm.The liquid perfusion test showed that the design vascular structure could achieve blood flow.The tissue engineered vascular scaffold prepared by this method not only has morphological characteristics similar to the natural diploic vein,but also has a parameterized controllability.This study lays a foundation for further optimization of scaffold structure,and promotes the development for skull vascularization technology.