疾病动物模型,组织工程猪心脏瓣膜 z-bio 2021-10-28 677

　　Valvular heart disease is an important disease threatening human health. The main treatment is to replace the heart valve. At present, the valve substitutes commonly used in the clinical treatment of valvular heart disease are mainly mechanical valves and biological valves. With the rapid development of biotechnology, tissue-engineered heart valves, which are potential ideal artificial heart valves for the heart, have attracted attention in the field of heart valve surgery. The ideal tissue engineering valve is made of a biodegradable material as a scaffold, and autologous cells are planted in the scaffold material. By self-modifying and updating the tissue-engineered valve, it gradually becomes the patient's own valve. However, experimental studies have found that the adhesion of seed cells to the scaffold material is an unresolved problem. The researchers then put forward a general theory of tissue engineering valves, that is, the use of animal heart valves as stent materials. The porcine aortic valve is anatomically and histologically similar to the human heart valve. The decellularized natural valve scaffold retains the structure and function of the complete extracellular matrix, provides a microenvironment important for cell adhesion and growth, and has excellent biomechanical properties. An important scaffolding material for constructing heart valves through tissue engineering. Early studies performed anti-immune rejection or decellularization effects on porcine heart valves and applied them directly, but failed. For example, Schreiber et al. Reported a clinical trial of a porcine pulmonary artery catheter (SPVC) treated with ShelhighNo-React (NR-4000PAseries). From May 2004 to May 2005, 34 cases of SPVC of different specifications are planned to be transplanted. As a result, after transplanting 15 catheters to 13 patients, an earlier failure was observed and temporarily cancelled. Only two patients died and it was not the cause of the catheterization, but the treated porcine heart valve showed extensive pseudoendometrial loss and chronic rejection after placement, with varying degrees of catheterization. It is not an ideal material for reconstruction of the right ventricular outflow tract (RVOT).

　　American CryoLife researchers use healthy porcine heart valves as raw materials, and use chemicals to remove cellular components that may cause immune rejection and transplant them into the recipient. They call this a decellularized porcine valve synaptic valve. In the stage of animal experiment and clinical application in adult animals, the structure of the valve stent grows well and is covered with autologous endothelial cells. However, due to severe immune rejection during the application to pediatric patients, the clinical rejection of the Synergraft valve must be terminated, which would cause the graft valve to rupture and rot and kill three patients. After the decellularized porcine heart valve was used as a stent, the endometrium was coated by tissue engineering, and good results were obtained. Schiralli et al. Since 2001, the effect of Carpentier EdwardsTM (CE) porcine valve catheter in children and adults with congenital heart disease has been retrospectively analyzed through RVOT reconstruction technology. Year 2009. A total of 208 patients underwent RVOT reconstruction with a single CE catheter with a catheter size of 12-30 mm. The perioperative mortality rate was 1.8% (4/208), and the remaining 95% of patients continued to be observed for 1-9 years. They found that catheter attenuation increased with time, contrary to catheter specifications. For catheters of all specifications, 70.3% of patients did not require reoperation within 8.2 years, and patients who used 25-30 mm catheters had no catheter attenuation. Therefore, they believe that in the mid-term observation, the CE catheter showed long-term, slow catheter stenosis.

　　Konertz et al. analyzed the interim research results of three research institutions. From January 2006 to September 2008, a total of 61 patients were implanted with porcine valve tissue engineering catheters of different specifications (valve specifications 11-27 mm). The early mortality rate was 8.2%, all attributable to non-valvular diseases. A total of 4 cases received reoperation due to valve insufficiency, 3 cases received RVOT intervention due to stenosis of the distal anastomosis, and 6 cases received re-interventional treatment due to pulmonary artery branch hypoplasia. Computed tomography and MRI showed that the tissue-engineered valve had normal structural features without obvious calcification. They concluded that MatrixP/MatrixPlus catheters are suitable for RVOT reconstruction in patients with congenital heart disease, and the mid-term performance of tissue engineering catheters is significantly better than other current artificial valves.