Phosphorylated chitin increased bone formation when implanted into rat calvaria with the Ti-device

Article type: Research Article

Authors: Song, Qin^a | Yagami, Kimitoshi^b | Furusawa, Toshitake^c | Takita, Hiroko^d | Kurasaki, Masaaki^e | Tokura, Seiichi^e | Morimoto, Koichi^f | Sammons, Rachel^g | Iku, Shouhei^h | Kuboki, Yoshinori^e;

Affiliations: [a] College of Pharmacy and Bioengineering, Chengdu University, Chengdu, Sichuan, China | [b] Department of Public Health, Matsumoto Dental University, Shiojiri, Japan | [c] Department of Bio-Engineering, Graduate School of Science and Engineering, Yamagata University, Yonezawa, Japan | [d] Faculty of Dental Medicine, Hokkaido University, Sapporo, Japan | [e] Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan | [f] Department of Biotechnological Science, Kinki University, Kinogawa, Wakayama, Japan | [g] Department of Biomaterials, School of Dentistry, Birmingham University, UK | [h] Jiangsu Alphay Biologcal Technology Co., Ltd, Nantong, China

Correspondence: [*] Corresponding author: Yoshinori Kuboki, Room A507, Faculty of Environmental Earth Science, Hokkaido University, Sapporo 060-0810, Japan. Tel.: +81 011 706 2252; Fax: +81 011 706 3864; E-mail: yk24936@gmail.com

Abstract: BACKGROUND:Previously we found that a group of phosphorylated proteins (SIBLINGs) in bone binds with the Ti-device, and increases the early bone formation around the Ti–implants remarkably. From these results, we explained the biochemical mechanism of a strong bond between living bone and Ti, which was discovered by Brånemark and colleagues. For the clinical application of our findings, we need a large amount of these proteins or their substitutes. OBJECTIVE:We aimed to create a new molecule that equips with essential functions of SIBLINGs, Ti-binding, and bone enhancement around the Ti implant. METHODS:We chemically phosphorylated chitin and obtained a soluble form of phosphorylated chitin (P-chitin). In this solution, we immersed the Ti-devices of web-form (TW) which we previously developed and obtained the P-chitin coated TWs. Then we tested the P-chitin coated TWs for their calcification ability in vitro, and bone enhancing ability in vivo, by implanting them into rat calvaria. We compared the P-chitin coated TW and the non-coated TW in regard to their calcification and bone enhancing abilities. RESULTS:Ti-devices coated with phosphorylated-chitin induced a ten times higher calcification in vitro at 20 days, and four times more elevated amount of bone formation in vivo at two weeks than the uncoated Ti-device. CONCLUSIONS:Phosphorylated chitin could be a partial substitute of bone SIBLING proteins and are clinically applicable to accelerate bone formation around the Ti implants, thereby achieving the strong bond between living bone and Ti.

Keywords: Chitin, phosphorylation, enhanced bone formation, Ti-device

DOI: 10.3233/BME-201079

Journal: Bio-Medical Materials and Engineering, vol. 31, no. 1, pp. 47-57, 2020