Design And Process Research Of Multi Factor Composite Molding System For Bone Cartilage Reconstruction

The natural bone cartilage tissue has a multi gradient hierarchical structure,which can realize the continuous transition of mechanical properties from rigid to flexible.In order to solve the problems of limited donors and stress fatigue in the treatment of bone cartilage injury,the research of artificial bone cartilage reconstruction by tissue engineering is in the ascendant.In order to enable artificial scaffolds to fit natural tissues in various characteristics,an in-depth study of artificial bone-cartilage reconstruction scaffolds with gradient mechanical properties is needed.At present,the stent forming process based on material component gradient or structural pore gradient still had problems such as insufficient mechanical properties,gradient curve limitation and poor biocompatibility.Therefore,a multi factor composite bone cartilage reconstruction scaffold forming system was designed based on 3D printing process,and the two were composited to realize the continuous transition of mechanical properties.In addition,the laser remelting process was designed to further control the mechanical properties of the samples.The main contents of this paper were as follows:1.Based on the representative volume element method,the reinforcement characteristics of oriented carbon nanotubes on polycaprolactone matrix were analyzed;The results show that the temperature distribution of the fluid was uniform and the viscosity was low at 120 ℃,and the instantaneous fluctuation of flow was less than4.22%.2.The multi factor composite bone cartilage scaffold forming system was designed and built.The three-dimensional forming platform,melt extruder,wire extruder and laser remelting parts were designed,selected and built to realize the composition of wire extrusion,melt extrusion and laser remelting process.3.The extrusion parameters of the bone cartilage scaffold forming system were adjusted.The step response of the mixing control was rapid,the refueling volume was about 250mm3,and the gradient control was uniform.The bone scaffolds were printed layer by layer and formed continuously as a whole.4.The effect of laser remelting process on the tensile and bending properties of the support was studied.The results showed that the tensile modulus and tensile limit of the sample increase by 11.41% and 13.87%when the light receiving amount was small.With the increased of the light receiving amount,the tensile and bending mechanical properties of the sample could be controllably reduced.