A Prophase Study Of Application About Human Nasal Septal Chondrocytes,new-style And Modified PLA(Polylactic Acid)Polymer In Cartilage Tissue-engineering ～*

Abstract Objective: To study the biological characteristic of the human nasal septal chondrocytes as seed cells and the new-style PLA (Polylactic acid) polymer with higher porosity as cell-conveyer in cartilage tissue-engineering, and to provid experimental evidence for using human nasal septal chondrocytes and the new-style PLA polymer with higher porosity to reconstruct the defects of ear, nose, throat and tracheae. methods: 1. Study on human nasal septal chondrocytes: To get the transparent cartilage form adult human nasal septum, digest it to get chondrocytes. We observed the biological characteristics of the chondorcytes cultured in vitro. The growth of the chondrocytes cultured in vitro were obviously enhanced when IGF-I were added, the mechanism of the effect on chondrocytes induced by IGF-I were studied using flow cytometer. We also established an apoptosis model of human chondrocytes induced by ultraviolet radiation in vitro, and to observe the effect of insulin on the human nasal septal chondrocytes?apoptosis which was induced by ultraviolet radiation. 2. Study on the new-style and modified polymers.(l). The highly porous new-style PLA polymer was made and its degradation in vitro and biodegradation , biocompatibility in vivo were observed. (2). PLA-co- P -hydroxy-ethyl ester acrylic acid was made and its biocompatibility and security in vivo were estimated. (3)The rabbit chondrocytes- highly porous new-style polymers autografts were implanted in vivo and the formation of neocartilage was observed on time sequence. Results: 1. Chondrocytes: (1). Chondrocytes of nasal septal cartilage can grow normally in vitro in monlayer. They can secrete glycosaminoglycan, alkaline phosphatasc .We observed the formation of its phenotype marker --type II - 10- collagen by immunohistochemistry reaction. The phenotype of chondrocytes can maintain 4 generations when cultured in monolayer in vitro.(2).Insulin- like growth factor-I can enhance the proliferation of nasal septal chondrocytes, and shorten the time of Gl phase and G2M phase in the cell cycle. (3). Ultraviolet radiation can induce the apoptosis of human nasal septal chondrocytes and insulin can suppress it. 2.The new-style and modified PLA polymer: (1). The mid-molecular highly porous new-style PLA has ideal characteristic of degradation and biocompatibility. (2). PLA-co- P -hydroxyethyl-ester has good characteristic of degradation and biocompatibility. It has good safety and hydrophilic property. (3) Chondrocytes-higher porosity new-style PLA polymer can form neocartilage when cultured in vivo. Conclusion: 1. Human nasal septal chondrocytes can be expanded in vitro and used as cartilage tissue-engineering seed cells 2. Insulin-like growth factor-I can promote the chondrocytes? proliferation, and insulin can suppress their apoptosis. 3. Ultraviolet radiation can induce the apoptosis of human nasal septal chondrocytes, which can be used for detecting the influencing factors on the apoptosis of chondrycytes in vitro. 4. The new-style PLA has good characteristic of degradation and biocompatibility. The highly porosity is available for the chondrocytes to grow in it. The chondrocytes-h...