Experimental Study Of Cartilage Tissue Engineering With The Acellularmatrix

ObjectiveCartilage is a type of connective tissue in which the intercellular material has rigid consistency, although the tissue is less resistant to pressure than bone.The main functions of cartilage are to support soft tissue and to provide a sliding area for joints, thus facility bone movements. Cartilage contains much intercellular material include collagen matrix and cartilage cells. The physiologic properties of cartilage depend mainly on the physicochemical characteristics of its matrix, which contains collagen or collagen plus elastin associated with pro-teoglycans.Multiple approaches have been used to replace lost, damaged, or diseased cartilage. These include synthetics, biosynthetic constructs, cross - linked biological and allograft. As a result of investigations using these approaches, the importance and complexity of matrix component has become increasingly evident. An ideal approach to replacing lost cartilage would be to use a synthetic or biosynthetic material.Because cartilage is reputed to be an" immunologically privileged" transplanted tissue that is weakly antigenic, it has been hypothesized that cartilage allografts fare nearly as well as autografts. This simply is not true. A careful study of the literature reveals that allograft enthusiasts have been misled by encouraging early results. Clinical experiences and the relative studies suggest that grafted cartilage dose evoke transplantation antigens and that the rejection re-sponse is merely delayed by the physical barrier that the matrix in terposes between the chondrocytes and the cells of the immune surveillance system of the recipient hostAn exciting new strategy, however, is poised to revolutionize the treatment of patients who need new vital structures, Tissue Engineering, which may create man - made tissues or organs, known as neo - tissues or neo - organs. In one scenaric, a tissue engineer injects a given molecule such as a growth factor or implants a structure that can induce the cells of the host grow - in to a wound or an organ that requires regeneration. The immigrated cells will turn into the right type of cell and regenerate the wounded tissue. In the second, the patient receives cells - either his or her own or those of a donor - that have been harvested previously and incorporated into three - dimensioned scaffolds of biodegradable polymers, such as PGA and PLA. The entire structure of cells and scaffolding is transplanted into the wound site, where the cells replicate, reorganize and form the new tissue. At the same time, the artificial polymers break down, leaving only a completely natural final product in the body - a new tissue. But there are still a lot of problems in the development of the materials of scaffolds which barrier the further advance of tissue engineering in the second way. However, there is a break - through in thefirst way, that is the development of acellular tissue matrix derived from the nature tissue by extracting the cells of it Now an acellular human dermal allograft (AlloDerm) is regulated by the U. S. Food and Drug Administration ( FDA) as human tissue and is indicated for transplantation to repair or replace damaged or inadequate dermal tissue. Also, a series of acellular matrix of coronary artery, heart valve and bladder have been developed successively by the scientists in the U. S. , Germany and Canada. These exciting facts encourage us to try a new kind of acellulax matrix, Cartilage Acellular Matrix. The work we do here is just the first step of the research. What we want to know is the effect of the method that have been used y other scientists to extract tissue cells on the histological contents, properties of mechanics and antigenility in cartilage. If and how the acellular matrix is used as the biomaterial to repair the wounded cartilage.Methods1. Cell extractionThe extracting process is based on Courtman's four - step method combining with the result of our preliminary experiment (1)The stored cartilage samples were immersed in a hypotonic tris buffer...