Tissue-Engineered Human Neocartilage Formation Using Human Adult Auricular Cell Line

The purpose of these studies was an establishment of human auricular chondrocyte cell line using retrovirus mediated v-myc transfer, characterizing the human auricular chondrocyte cell line by type II collagen mRNA expression and transplantation of human auricular cell line into immunological incompetent nude mice to establish neocartilage formation. Also, I evaluated the growth rate of chondrocyte cell line to measure the cellular proliferative potency. I have established the human auricular chondrocyte cell line integrated v-myc and confirmed by v-myc transduced Myc protein expression by immunohistochemistry and immunoblotting study. And, growth rate of established human auricular chondrocyte cell line increased 4 folds times faster than primarily cultured human auricular chondrocyte. The established human auricular chondrocyte had type II collagen mRNA upto 8 months in monolayer culture. And we observed formation of neocartilage on the back of nude mice using chondrocyte cell line/fibrin glue polymer at 12 weeks transplantation.

Tissue Engineered Cartilage Formation using Human Hyaline Chondrocytes and Elastic Chondrocytes

The purpose of this study was to evaluate the influence of different types of PLGA scaffolds on the formation of human auricular and septal cartilages. The scaffolds were formed in tubular shape from 110,000 g/mol PLGA (poly lactic glycolic acid) and 220,000 g/mol one. Elastic cartilage was taken from the ear of a patient aged under 20 years old and hyaline cartilage from the nasal septum. The chondrocytes cells were then isolated by Klausburn method. After second passages, the chondrocytes were seeded on the PLGA scaffolds followed by in vitro culture for one week. The cells-PLGA scaffold complex was implanted at the back of nude mouses for 8 weeks. The tissue engineered cartilages were separated from nude mouse and examined histologically after staining with the Hematoxylin Eosin and Verhoeff. The formation of extracellular matrix and the porosity of the scaffolds were examined by scanning electron microscopy. The pores were well formed and uniformly distributed in both 110,000 g/mol and 220,000 g/mol PLGA scaffolds. The extracellular matrix was formed better in 110,000 g/mol PLGA compared to 220,000 g/mol one. And hyaline cartilage was proliferated better in vitro culture than elastic cartilage. After 8 weeks in vivo culture, cartilage was well formed with 110,000 g/mol PLGA, however lumen was collapsed. In contrast with 220,000 g/mol PLGA scaffold, neocartilage was formed in minimal amount while the architecture of scaffold was well preserved. Elastic cartilage seems to be better than hyaline one in terms of neocartilage formation. From the analysis after Verhoeff staining the cartilages, the neocartilage from elastic cartilage was proved to be elastic cartilage. In summary, there was no significant difference between elastic cartilage and hyaline cartilage in their morphologies, proliferation rates and the degree of cartilage formation since they were tissue engineered, however marked difference was found in neocartilage formation and preservation of scaffold architecture between 110,000 g/mol PLGA scaffold and 220,000 one. From the present findings, it is concluded that the influence of scaffold materials is significantly higher than that of different types of cells on the formation of new tissues.