Single-coaxial Composite Electrospinning Process And Performance Evaluation Of Threelayer Regenerative Vascular Scaffold

According to statistics of the World Health Organization,cardiovascular disease accounts for about 31% of global deaths,and has become one of the main hazards facing human health.Therefore,the research of tissue engineering and material manufacturing for regenerating vascular scaffolds has become a hot topic both at home and abroad.Because the preparation technology of scaffold is not yet mature,the quality problems of spinal scaffold,such as ridge,thread and injury,impede the development and clinical application of scaffold.Therefore,it is of great research value and practical significance to prepare a vascular scaffold that meets the requirements of tissue engineering performance,and to solve the problems affecting the quality of the vascular scaffold,thereby promoting the development and clinical application of the vascular scaffold.In this dissertation,based on the research of composite forming technology of vascular scaffolds,aiming at the preparation of vascular scaffolds that meet the requirements of tissue engineering,a compound forming process combining single axis and coaxial electrospinning is proposed.The preparation process and structural design of the vascular scaffold,detailed analysis of the influence of process parameters on the quality of electrospinning,and the theoretical and experimental studies on the in vitro and in vivo biocompatibility of the prepared vascular scaffold.In this paper,the background and significance of scaffold research are discussed in detail,and the development status and current research status of related researches are analyzed in detail.1)According to the basic performance requirements of blood vessels and blood vessel scaffolds,combined with the three-layer structure and material properties of blood vessel scaffolds,a composite forming process method for blood vessel scaffolds is proposed,and the mutual influence relationship between the parameters of the composite forming process is given.According to the law of mass conservation,charge conservation and conservation of momentum,the theoretical model of Taylor's vertebral body is deduced.It provides a theoretical support for the optimization of electrospinning process.In order to prepare the scaffold that meets the requirements of biomechanical properties of the tissue engineering,a composite experimental system for vascular scaffold is established.2)In order to improve the quality of scaffold formation,a numerical model was established for the outer ridge structure and inner thread structure of the vascular scaffold.The stress concentration phenomenon caused by the outer ridge structure and the inner thread structure was analyzed in detail by using the simulation analysis method.Simulation analysis of the blood flow was carried out according to the fluid mechanics theory,continuity equation and Navier-Stokes equation.It is verified that the internal thread structure can disrupt the blood laminar flow of the scaffold,disrupt the blood flow rate and weaken the biocompatibility of the scaffold.3)Taking the outer ridge structure of the scaffold and the interface effect of the coaxial electrospinning as the research object,combined with the Freundlich isothermal adsorption equation,the effect of 1 wt% Tween-80 on the preparation of the scaffold was analyzed,and the smooth structure of the outer layer of the vascular scaffold was prepared,which solved the problem of no core / shell structure of the coaxial nanofibers.4)Taking the internal thread structure and the physical damage of the inner surface of the scaffold as the research object,the effect of Pluronic F127 on the preparation of the scaffold was analyzed in detail with the help of the thermo sensitive characteristics of Pluronic F127.The smooth structure of the scaffold was achieved,and the physical damage of the inner surface caused by the rigid detachment of the blood vessel bracket from the receiving shaft was solved.According to the above research results,the vascular scaffolds were made by using a preliminary composite test system.The in vitro and in vivo experiments of the fabricated vascular scaffolds were carried out.The results showed that the composite scaffolds fabricated by the composite forming process met the requirements of tissue engineering,and the feasibility of the composite forming process was verified.