combination of inductive effect of lipopolysaccharide and in situ mechanical conditioning for forming an autologous vascular graft in vivo
by:MX machinery 2020-11-18
Autologous vascular graft has good biological compatibility and prognosis. However, previous studies have shown that the poor yield and stability of implanted bare polymer tubes into the growth of autologous tubular tissue in animals limits these studies. In order to improve the yield of tubular tissue, we have adopted a design to add a covered autologous whole blood stent containing lps (LPS). In addition, we apply dynamic mechanical stimulation in the body by circulating inflatable silicone tube to improve the mechanical properties of the harvested tissue. The effectiveness of the modification was tested by implantation of the tube into the abdominal cavity of rats. A group without mechanical stimulation as a control. After 24 days of culture including 16 days of circulating mechanical stimulation, we harvested the tubular tissue formed on the silicon tube for analysis or further autologous insertion of blood vessels. Compared to tissues that do not have cyclic dynamic stimulation, tubular tissues that receive this treatment during in vivo culture have stronger mechanical properties, better smooth muscle division, at the end of the incubation period, more collagen and elastic protein expression is present in the abdominal cavity. After 4 months of implantation, the graft remains a patent and shows that there are endothelial cells and smooth muscle cells. This model provides a new direction for the development of vascular tissue engineering. Many clinical conditions, such as coronary artery disease, terminal- Staging of kidney disease and peripheral arterial occlusion disease. Many of these situations are universal and critical. For example, coronary artery disease is one of the main causes of mortality and morbidity around the world. In the U. S. An estimated 660,000 new coronary events ( First hospital death from myocardial infarction or coronary heart disease) About 305,000 cases of coronary recurrence will occur within a year. In 2010, an estimated 397,000 inpatient bypass operations were performed. In this operation, the choice of vascular graft is essential. For example, in coronary artery bypass surgery, Is the result of the program worse than the first time? Execute the program. More frequent use of radial arteries in re-re Surgery, but the rate of fluency was lower than that of the left internal Milky artery and great hidden vein graft. The lack of suitable bypass graft remains a major problem during Reconstruction Doing bypass surgery, may result in worse results than the first one Bypass. However, there is still not enough artificial channels for coronary artery bypass grafting. Tissue Engineering provides hope for vascular bypass grafting. Although clinical trials have been conducted on tissue engineered blood vessels (TEBV) Composed of somatic cells without synthetic materials, the production time is long (7. Average 5 months) It hinders its application. Another way to train TEBV with somatic cells is to train theme. In the body of the receiver. In a clinical trial conducted by Sparks , The use of autologous subcutaneous tissue as a vascular graft can lead to adverse results. However, the graft contains synthetic polyester mesh, which is a non- Degradation of foreign bodies for better mechanical support. For 100% autologous subcutaneous tissue tubes, methods to make them stronger have been proposed, including cyclic mechanical stimulation, which has been well documented in the field of manufacture of TEBV. Some researchers tried to use the abdominal cavity to cultivate vascular graft by forming autologous tubular tissue around the implanted silicone tube, as well as to resist The solidification properties of the inverted interskin conform to the features of the tube cavity side (Campbell . ). However, the model is limited by the yield of tubular tissue, ranging from one to three of the four tissues. Although the yield of 100% can be achieved by adding polymer sheets or grids, the tubular tissue is not completely autologous. This method is also applied to autologous transplants of organs such as bladder, uterus and vas deferens ( Use polyethylene balls and boiled blood clots as molds) , And urethra graft ( Mold with silicone tube) And achieved good results. This proves its utility in regenerative medicine. However, the report did not elaborate on the yield, and the reporting duration required to produce useful graft in mouse models ranged from 2 to 8 weeks. This restriction may increase the uncertainty of its further application. It is well known that the collagen coating on the plasma treatment bonded silicone material can optimize the biological compatibility, but the pre- Coating collagen is unpredictable. Since collagen can be synthesized by activating the macrophages, we used lps (LPS) As a \"booster\" for the production of autologous and applicable extracellular matrix, this is an effective autophagy activator (ECM) In the receiver. Let\'s introduce a paper towel here. Engineering Systems using rodent animal models, including LPS, autologous whole blood stent, and cyclic mechanical stimulation, were used in the abdominal \"Biological Reactor. Vascular graft was made from the abdominal cavity and implanted as autologous middle aortic graft for up to 4 months. We conducted a study here to determine the mechanical properties, fluency, ECM expression, and smooth muscle division of the vascular graft produced by this method.