Chondrocytes Amplification And Construction Of Tissue Engineered Cartilage With Liquid Gel Experiments

Once damaged, articular cartilage has a limited capacity for self-repair . To overcome this problem, the autologous chondrocyte transplantation technique has been introduced for repair of articular cartiliage defects. However, a major challenge in tissue engineering is the availability of a sufficient number of cells with the appropriate phenotype for delivery to damaged cartilage. Expansion of chondrocytes in two-dimensional culture systems results in their defferentiation . For example, the chondrocytes loose their spherical shape and acquire a fibroblast-like appearance.Accordingly, expression of hyaline cartilage markers, aggrecan and collagen typeⅡ,decreases,while expression of non-hyaline cartilage specific collagen typeⅠincreases.In an effort to overcome this problem, the culture of chondrocytes on microcarriers, has been investigated as a means to maintain a chondrocytic phenotype. Besides serving as substrates for the propagation of anchorage-depentiateds, the microcarrier culture system offers an attractive method for enhancement of phenotype expression .This study evaluated the postexpansion chondrogenic potential of microcarrier-expanded rabbit articular chondrocytes . Comparable doubling times and the sulfate glyosaminoglycans (GAG) content were obtained in monolayer and on microcarriers. Cytodex-3 microcarriers were selected . This study also evaluated the in vitro behaviour of chondrocytes expanded on microcarriers in collagen gels and temperature-responsive hydroxybutyl chitosan. Results showed that culture of chondrocytes on microcarriers may offer useful cell expansion opportunities and the composition of cartilage-like tissue can be obtained by growing chondrocytes in these two kinds of scaffolds.The main contents of this study were as following:1. Study on the chondrocytes scalable expansion on microcarriers. 2. Study on engineering cartilage formed by chondrocytes and liquid collagen in vitro .3. Study on engineering cartilage formed by chondrocytes and hydroxybutyl chitosan in vitro.