Preparation And Study Of Fiber-based Bionic Artificial Vessels

People's life are facing the risk from vascular diseases such as atherosclerosis,inflammatory vascular disease,functional vascular disease,injured vascular disease,tumor vascular disease,generally.The type of blood vessels which are used for transplantation in clinic therapy can be divided into native vessel and artificial vessel.However,the study of man-made vessel is one of the hot-button in the world because of the limited source of native vessel and the difficulty of surgical operation.In this dissertation,PU-PCLcomposite system are the main point of the study,and the four layer structure of continuous phase can be formed by using the region in which the fibers are ordered and the technology which is combined with the traditional wet spinning process and the advanced nano-fiber preparation technology.Good biocompatibility and long term patency rate can be seen from the vascular substitute which is produced by the new method.Furthermore,these products also have some other excellent properties including mechanical property,crease resistance,fatigue resistance and water permeability.This research studying the quality such as the construction,appearance and mechanical property of man-made vessel by using SEM,Instron strength machine and some other ways;the properties of the crease resistance and water permeability are studied by using a new characterization method which was developed according to the ISO7198.After a plenty of repeated experiments(about theartificial blood vesselpreparing instrument)and data modeling,the conclusion can be summarized: artificial blood vascular surface can be uniformedif the pitch of the rollers is equal to the diameterof the filament;The product of the speed of the stepper motor and the rotational speed of the winding spindle is equal to the product of the pitch of the rollers and the diameter of the filament;The perfusion is proportional to the winding speed and diameterof the filament.The tensile fracture strength of artificial blood vessel can be affected by the length of coagulation bath and the solid content of PU-PCL in spinning solution.With the increase of coagulation bath length,the axial tensile strength and tensile strength of the vascular prosthesis increased first and then decreased while the solid content is unchanged.Similarly,when the length of coagulation remaining and the solid content raising,the axial tensile strength and tensile strength of the vascular prosthesis showed an increase at first and a decrease later as well.Therefore,when the coagulation bath length is 50 cm,and the content of PU-PCL spinning solution is 18%,the axial and radial tensile fracture strength(mechanical property)of the artificial blood vessel is the largest.When the solid content is unchanged,the shorter the coagulation bath length,the less the mechanical loss of the artificial blood vessel in the axial and radial direction,the better the anti-fatigue performance.When the coagulation bath length is constant,the larger the solid content,the worse the axial fatigue resistance of the artificial blood vessel,and the better the radial fatigue resistance.When the coagulation bath length is 60 cm,PU-PCL in spinning solid content is 20%,the artificial vessel which is made by the way of micro-nano cooperative biologyshowing the best property of crease resistance,meaning that this product can fully meet the requirement of bending degree of vessel even when people doing some sports.The water permeability of this kind of vessel is growing with the increasing of the length of coagulation bath and the solid content of PU-PCL in spinning solution.