A novel, self-assembled artificial cartilage–hydroxyapatite conjugate for combined articular cartilage and subchondral bone repair: histopathological analysis of cartilage tissue engineering in rat knee joints

• Main Authors: Kumai T, Yui N, Yatabe K, Sasaki C, Fujii R, Takenaga M, Fujiya H, Niki H, Yudoh K
• Format: Article
• Language: English
• Published: Dove Medical Press 2019-02-01
• Series: International Journal of Nanomedicine
• Subjects: Cartilage tissue engineering; Subchondral bone; Articular cartilage; Osteoarthritis; Self assembly; Hydroxyapatite
• Online Access: https://www.dovepress.com/a-novel-self-assembled-artificial-cartilage-hydroxyapatite-conjugate-f-peer-reviewed-article-IJN

Takanori Kumai,1 Naoko Yui,1 Kanaka Yatabe,1 Chizuko Sasaki,2 Ryoji Fujii,3 Mitsuko Takenaga,3 Hiroto Fujiya,1 Hisateru Niki,4 Kazuo Yudoh3 1Department of Sports Medicine, St Marianna University School of Medicine, Miyamae-ku, Kawasaki 216-8511, Japan; 2Institute for Ultrastructural Morphology, St Marianna University Graduate School of Medicine, Miyamae-ku, Kawasaki 216-8512, Japan; 3Department of Frontier Medicine, Institute of Medical Science, St Marianna University School of Medicine, Miyamae-ku, Kawasaki 216-8512, Japan; 4Department of Orthopaedic Surgery, St Marianna University School of Medicine, Miyamae-ku, Kawasaki 216-8512, Japan Purpose: We previously created a self-assembled cartilage-like complex in vitro from only three cartilage components, hyaluronic acid (HA), aggrecan (AG) and type II collagen, without other materials such as cross-linking agents. Based on this self-organized AG/HA/collagen complex, we have created three novel types of biphasic cartilage and bone-like scaffolds combined with hydroxyapatite (HAP) for osteochondral tissue engineering. These scaffolds have been developed from self-assembled cartilage component molecules and HAP at the nanometer scale by manipulating the intermolecular relations. Patients and methods: The surface structure of each self-organized biphasic cartilage and bone-like scaffold was evaluated by scanning electron microscopy, whereas the viscoelasticity was also analyzed in vitro. Three types of artificial cartilage–HAP conjugates were implanted into an osteochondral defect in rat knee joints, and bone and cartilage tissues of the implanted site were examined 4 and 8 weeks after implantation. The tissues were examined histopathologically to evaluate the effects of the implantation on the articular cartilage and subchondral bone tissues. Results: Our in vitro and in vivo data reveal that the self-organized biphasic cartilage and bone-like scaffold conjugated with HAP are superior to the scaffold with no HAP in both cartilage regeneration and subchondral bone regeneration. Conclusion: Our present study indicates that the self-organized biphasic cartilage and bone-like scaffold, which is conjugated with an HAP layer, may have potential not only to repair articular cartilage defects but also to ameliorate the degeneration of subchondral bone in the diseases with osteochondral defect. Keywords: cartilage tissue engineering, subchondral bone, articular cartilage, osteoarthritis, self assembly, hydroxyapatite