Affiliations: Department of Orthopaedic Surgery, School of Medicine, Toho University, 6‐11‐1 Omorinishi, Ota‐ku, Tokyo 143‐8541, Japan | Graduate School of Engineering (International Innovation Center (KU‐IIC)), Kyoto University, Yoshida‐Hon‐machi, Sakyo‐ku, Kyoto 606‐8501, Japan | Institute for Frontier Medical Sciences, Kyoto University, 53 Kawahara‐cho, Shogoin, Sakyo‐ku, Kyoto 606‐8507, Japan | Department of Orthopaedic Surgery, Nara Medical University, 840 Shijyou‐cho, Kashihara‐city, Nara 634‐8522, Japan | Department of Orthopaedic Surgery, Shinshu University, 3‐1‐1 Asahi, Matsumoto‐city, Nagano 390‐0802, Japan | National Institute of Sericultural and Entomological Science, 1‐2 Owashi, Tsukuba‐city, Ibaragi 305‐8634, Japan
Note: [] Corresponding author: Naohide Tomita, Graduate School of Engineering (International Innovation Center (KU‐IIC)), Kyoto University, Yoshida‐Hon‐machi, Sakyo‐ku, Kyoto 606‐8501, Japan. Tel. and Fax: +81 75 753 9200; Fax (office): +81 75 771 7286; E‐mail: [email protected]‐u.ac.jp.
Abstract: Fibroin‐hydrogel sponge and collagen gel were used as scaffold for in vitro cartilage regeneration. Fibroin‐hydrogel sponge was formed by phase separation from freezed fibroin solution. Chondrocytes were harvested from proximal humerus, distal femur and proximal tibia of 4‐week‐old Japanese white rabbits and inoculated in the fibroin–hydrogel sponge and collagen gel. Those constructs were cultured in DMEM supplemented with 10% FCS and 50 ml L‐ascorbate at 37°C. Histological observation, measurement of sulfated glycosaminoglycan and cell density were carried out at 3, 7, and 14 days after the cultivation. Well‐defined cartilage tissue can be seen both in the fibroin–hydrogel sponge and in the collagen gel. The matrix was intensely stained by safranin‐O and showed a metachromatic reaction in both group. However, the quantity of sulfated glycosaminoglycan and cell density of the fibroin–hydrogel sponge group were increased more rapidly than these of the collagen gel group. Thus, the chondrocytes proliferated in the fibroin sponge without losing their differentiated phenotype. It is possible that culture environment in the fibroin sponge was suitable for chondrocytes regeneration.
