S022023 RGD導入フィブロイン平面上に播種された軟骨細胞への低出力超音波パルス刺激の影響([S02202]細胞および分子のマイクロ・ナノスケール解析(2))

Abstract

Several reports suggest that low-intensity pulsed ultrasound stimulation (LIPUS) facilitates chondrogenesis. Recently it has been suggested that LIPUS may be transmitted via Integrin. In this study, the Arg-Gly-Asp (RGD) amino acid sequence, which is a ligand of Integrin, was induced to the fibroin substrates by either gene transfer or physical mixing, and the variation of chondrocyte response to LIPUS was evaluated. Chondrocytes were seeded on three kinds of fibroin substrates: 1 wild-type, 2 transgenic and 3 mixed. LIPUS stimulation, with spatial and temporal average intensity of 30 mW/cm2, was applied to the chondrocytes at 12, 36, 60 hours and administered for 20 minutes each time. The results showed that GAG production, number of chondrocytes and mRNA levels of aggrecan, Sox 9 and Integrin ^ 1 was enhanced in the transgenic group by LIPUS administration, but these LIPUS-derived changes were not found in the wild-type and mixed groups. We previously reported that the adhesive force between chondrocytes and RGD transgenic fibroin surfaces was higher than that for mixed fibroin, suggesting that adhesive force is translated via RGD which bonds covalently to the fibroin proteins for the transgenic group. The present results suggest that the early biological adhesion via RGD on the transgenic fibroin is sensitive to LIPUS.