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Comparative Study on Cell Extraction with Different Methods in Porcine Aortic Valves

Author: ZhuXiaoMing
Tutor: FaXianEn
School: Zhengzhou University
Course: Cardiovascular Surgery
Keywords: Tissue Engineering Heart valve Biological materials Acellular matrix
CLC: R654.2
Type: Master's thesis
Year: 2007
Downloads: 47
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Abstract

Background and Purpose heart valve replacement surgery as a treatment for end-stage heart valve disease, an effective means widely used in clinical, artificial heart valves, along with the launching of this technique also has experienced 50 years of development. With the constant improvement of the quality of the prosthetic valve, the majority of valve disease quality of life and life expectancy has been greatly improved, but clinical two categories of human cardiac work valves - mechanical valve and bioprosthesis are some defects for life: the mechanical valve implantation anticoagulant to prevent the occurrence of thromboembolic complications; the heterogeneous biological lobe durability, prone to calcification, decay, and the the cryopreservation with valvular existence rejection, and donor source of difficulties. And existing artificial heart valves do not have the biological activity transplant can not be with the body growth, is particularly detrimental for the low age valvular patients. Therefore, to build an ideal artificial heart valves to become the focus of the study of heart valve surgery. Nineties of the last century, the organization founded Engineering (Tissue Engineering, TE) for the study of artificial heart valves to provide new ideas and methods, application of tissue engineering principles to build artificial heart valves become the new direction of the heart valves. Biodegradable scaffold for tissue engineered heart valve (Tissue Engineering Heart Valve, TEHV) The basic idea is: the high concentration of autologous cultured in vitro living cells grown in the natural or synthetic, and its firm adhesion, growth to build artificial heart valves have normal valvular tissue metabolism of functions. Compared with the existing artificial heart valves, tissue engineered heart valve has the following advantages: 1. The structure of the tissue engineered heart valve with normal heart valves are basically the same, with respect to the mechanical valves have better hemodynamic characteristics. 2. Cellular components of the tissue engineered heart valve internal and surface normal valvular and non-immunogenic autologous cells, without anticoagulation. 3. Tissue engineered heart valve with biological activity, the random body growth and development, not easily degraded, decay, durability, and can effectively avoid the second operation. In theory, the tissue engineered heart valve completely overcome the shortcomings of the current clinical use of two types of artificial heart valves, has good prospects for clinical application. Heart valve tissue engineering research in general, including: the source of seed cells, the valve scaffold material selection and preparation, seed cells on the stent planting and TEHV build three aspects. The valve scaffold tissue engineered heart valve, it is a support cell adhesion station and decided the basic configuration of the valve and work. The stent not only to provide seed cell growth space and valvular tissue generated template, to provide sufficient mechanical strength to withstand the tension and shear force arising from the impact of the fast blood flow in the the valvular cell matrix prior to the generation, but also determines the transplant After the body to adapt, combine, repair and substitution effect. It can be said, material selection and preparation of the bracket is to limit tissue engineered heart valve can really be a key factor used in clinical. Acellular matrix material the normal valve similar spatial structure and mechanical properties, and after acellular processing to eliminate immunogenicity is considered to be a useful clinical application prospects valve scaffold material. This study detergent, enzyme hydration method acellular porcine aortic valve tissue and biomechanical performance, the best way to explore the acellular matrix valve scaffold prepared. The first part of the method: porcine aortic valve leaflets off Cytoskeletal model. 1. Healthy adult pigs slaughtered after 15 minutes remove the aortic valve and a small amount of flap tissue, cut out the valve leaflets under sterile conditions in 75% ethanol disinfection. 2. The valve leaflets were randomly divided into five groups, respectively Triton (TrixionX-100), sodium dodecyl sulfate (SDS), deoxycholic acid (DCA), trypsin, nucleic acid enzymes one or a few reagents carried decellularized. 3. Decellularized valve leaflets into the valve leaflets preservation solution at 4 ℃. Part II: evaluation acellular effect. 1. Groups acellular valve leaflets the acellular effects and acellular matrix fiber arrangement of light microscopy, scanning electron microscopy; 2. Test groups acellular valve leaflets thickness, water content, shrinkage temperature, with fresh valve leaflets group control to observe the different methods of removing the cells of the physical properties of the valve leaflets. 3. DNA quantitative analysis acellular valve leaflets cell nucleic acid components remains the case. Results (1) the acellular matrix trypsin and detergent treatment had no significant effect on the physical and chemical properties of the valve leaflets. (2) the trypsin Triton EDTA nucleic acid enzymatic and trypsin the DCA EDTA nucleic acid enzymatic cellular components of the porcine aortic valve leaflets can be completely removed. (3) The trypsin the DCA EDTA law and the the SDS method failed to effectively remove cellular components of the porcine aortic valve leaflets. (4) trypsin the DCA EDTA nucleic acid enzymatic processing of porcine aortic valve leaflets decellularized completely the valve leaflets structure and physicochemical properties have not been significantly affected. Conclusions using trypsin the DCA EDTA nucleic acid enzymatic effectively stripped of the cellular components of the porcine aortic valve leaflets, physical and chemical properties of acellular matrix, is superior to other methods, is the ideal method of acellular tissue engineered heart valve scaffolds.

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