Study On The Technology Of High Molecular Compound Textile Artificial Blood Vessel

　　“ spin "Artificial blood vessel" is a textile made of high molecular compound Material Science Through textile machinery, tubular objects made by textile technology are then textured to form a soft spiral textile tubular fabric that can be bent 360 ° without distortion and collapse. Its function is to connect artificial blood vessels of corresponding caliber to save people's lives when human blood vessels are blocked, injured, ruptured, narrowed arteries or aneurysms need to be removed.

Development of artificial blood vessel materials

The development of artificial blood vessels began at the beginning of the 20th century. Scholars from all over the world first carried out a large number of animal experiments with tubes made of metal, glass, polyethylene, silicone rubber and other materials, but they were not widely used clinically because they were prone to intracavitary thrombosis in a short period of time. In 1952, Voorhees [2] first studied how to make vinylon into artificial blood vessels, which changed the impermeability of the wall of artificial blood vessels in the past. Then Voorhees, Blakemore and Jaretzki did a lot of clinical experiments and developed artificial blood vessels with meshes, which is a milestone in the history of vascular substitutes. With the continuous development of fiber materials and medical biomaterials, after Voorhees, workers in various countries have developed various materials and artificial blood vessels produced by various processing methods and used them in animal experiments and clinical applications. Later, experts tested many materials, such as PVC, PAN, silk, nylon and viscose fiber. The artificial blood vessels made of PAN and nylon will deteriorate in the body, so these two materials will soon be eliminated.

At present, synthetic fibers, such as polyester and polytetrafluoroethylene fibers, are the most widely used raw materials for artificial blood vessels. They have good structural stability and can work in the human body for a long time without degradation.

2 Research status of artificial blood vessel

Research Status of Vascular Prosthesis Abroad

After a long period of development, foreign vascular prostheses have become mature. At present, shaped seamless tubular vascular prostheses have been developed, and the diameter can gradually change with the length. This change in shape and diameter is accomplished by constantly changing the number of warp yarns and using a computer-controlled jacquard loom. This technology omits the post weaving process, and is especially suitable for weaving bifurcated fabrics. Tubular and cross tubular artificial blood vessels can be woven on the Raschel warp knitting machine. At present, many researches are focused on the application of semiconductor fibers, especially in the application of absorbable two-component fibers, surface modification and three-dimensional scaffolds.

Research status of artificial blood vessel in China

In recent years, the achievements and breakthroughs in the research and development of artificial blood vessels in China are mainly shown in the following aspects: (1) Biomechanical performance characterization of artificial blood vessels. In China, although the first generation silk artificial blood vessel was developed in the 1960s, the current market is still dominated by imported artificial blood vessels. Although there are many factors affecting product development, one of the main reasons is the serious lack of research on the basic biomechanical properties of artificial blood vessels. (2) A series of warp knitted vascular prostheses were developed, and the changes in the structure and properties of the vascular prostheses were studied from the textile structure and mechanical properties of the whole vascular prostheses and single fiber vascular prostheses. (3) In recent years, with the improvement of people's requirements for quality of life and the change of medical model, the general trend of surgical treatment principles has begun to develop in the direction of minimally invasive and simple. For arterial dilatation diseases, minimally invasive endovascular therapy has emerged in China. Its principle is to isolate the diseased blood vessels from the normal circulating blood flow by implanting metal stents and artificial vascular complex grafts into the blood vessels. The therapy has the advantages of small trauma, rapid recovery, small complications, simple and minimally invasive, and reliable curative effect.

3 Main problems in the development and use of artificial blood vessels

Main Factors Restricting the Development of Vascular Prosthesis in China

According to the survey, most of the artificial blood vessels used in the clinical operations in major hospitals in China are imported. Based on this situation, there are three main factors limiting the research and development of vascular prostheses in China. The first is the limitation of the development of polymer materials in China. For example, the development of polyurethane products for the development of small diameter artificial blood vessels and biodegradable materials with good biological properties for vascular tissue engineering substrates are not satisfactory. Second, there is a lack of good cooperation among various industries. The research and development of artificial blood vessels is an interdisciplinary subject involving material engineering, bioengineering, medicine, textile engineering and other disciplines. It requires professionals from various disciplines to break through the barriers between industries, cooperate closely, and work together to achieve greater progress. Third, there is a lack of research on the characterization of the biomechanical properties of artificial blood vessels. In the process of research and development, there is no appropriate test means to detect and evaluate the quality of products in vitro, and only short-term animal experiments are used for research.

　{page_break}

Main problems in the use of artificial blood vessels

　　 spin The quality problems of artificial blood vessels caused by processing and finishing mainly include: serious bleeding, poor anti desquamation performance, poor self support structure, easy collapse, poor longitudinal and radial compliance, etc. The maximum pore size and impermeability are the basic factors to achieve non blood seepage during surgery and cell growth after surgery. The permeability of fabric is closely related to the fabric density, fabric structure and yarn structure. At present, the important problem existing in the domestic artificial blood vessels is that the permeability of the fabric is relatively poor. Although the thickness of fabric can meet the requirements after various methods, permeability is still an important aspect of future research.

Therefore, it is necessary to fully understand the gap between domestic and foreign research on vascular prostheses and the constraints restricting the development of vascular prostheses in China, increase the strength of product development in China, and realize the localization of a series of products as soon as possible.

4 Future research focus of artificial blood vessel

Technology to solve the patency rate of small caliber artificial blood vessels

The ideal artificial blood vessel should have good histocompatibility, antithrombotic property, physical stability, anti infectivity and be easy for surgeons to use. The main problem of small caliber artificial blood vessel is that the artificial blood vessel has no anti thrombotic property at all. When the blood flows through the lumen, it is easy to form wall attached thrombus on the lumen surface of the artificial blood vessel due to the small blood flow and slow flow rate, and then the blood clotting becomes excessive, the blood flow becomes slower, and the thrombus layer thickens, which eventually leads to the occlusion of the artificial blood vessel. The late hyperplasia of smooth muscle thickens the intima and narrows the small caliber vascular lumen, which is also a major reason for the failure of vascular reconstruction.

Improve the compatibility between biomaterial surface and blood

Increasing the hydrophilicity of polymer surface can reduce the interaction between polymer and blood components. The improvement of the hydrophilicity of the polymer surface can reduce the free energy of its interface, reduce the amount of plasma protein and easily decompose, thus preventing thrombosis. The hydrophilicity of polymer surface can be improved by many methods, among which grafting the side chain of polyethylene oxide on the surface has proved to be a promising method.

Introduction of bioactive substances on the material surface

Curing some substances interfering with the interaction between blood and material surface on the surface of exogenous materials can improve their compatibility with blood. Although many bioactive substances have been applied, most of the work focuses on the solidification method of anticoagulant heparin.

Surface decoration of artificial blood vessel materials

Since there is no interaction between blood and normal vascular lumen, vascular endothelial cells are considered as a perfect blood compatible surface. Therefore, many scholars try to cover endothelial cells on the surface of foreign materials, especially artificial blood vessels, and improve their compatibility with blood. Although the surface of biomaterials is an ingenious and effective means to improve blood compatibility, the stability of this surface still has problems. Experiments have proved that the use of substances that promote endothelial cell adhesion, such as fibrin, fibrinogen or anti endothelial cell antibodies, is an effective way to stabilize the binding of endothelial cell nuclear synthetic materials.

Artificial blood vessel plays an important role in vascular transplantation. At present, there are artificial blood vessels with different diameters and shapes. According to different parts of the blood vessels, different materials and processing methods are used to make them have corresponding characteristics, which to some extent meets the needs of the people. With the improvement of living standards and medical standards. Since the artificial blood vessel is a part of the human body after being transplanted into the body, it must have good elasticity and dispersibility, suitable permeability to blood, fatigue resistance of continuous stretching and contraction, and aging resistance of human tissues and body fluids. These properties need to be further tested Research 。