Papers by Author: Hajime Sugai

Abstract: A new biodegradable adhesive(LYDEX) which is based on Schiff base formation had developed. LYDEX is easy to control the setting time and degradation speed and it has no risk of infection. In the previous study, LYDEX showed high bonding strength and low cytotoxicity in vitro[1]. In the present study, good bone repair was seen in rat bone defect models, especially in rapidly degrading type. On the other hand, slowly degrading type kept its shape longer without excessive inflammation. In rabbit critical defect model with hydroxyapatite granules (HAs), more newly formed bone was seen in rapidly degrading group and hydroxyapatite group, in 3weeks. In 6weeks, more new bone was seen in slowly degrading type group, whereas, almost no new bone was seen in deep area of the fibrin group, in 12weeks. Direct bonding between HAs and bone was seen in HA group and LYDEX groups. These findings suggest that LYDEX with hydroxyapatite granules can be a promising bone substitute.

Abstract: To improve the conventional and commercially-available medical adhesives such as cyanoacrylate, aldehyde-based, and fibrin glue, new bioadhesive has been prepared using medical and food additives as starting materials. Aldehyde groups could be easily introduced in dextran in the presence of sodium periodate in aqueous media, and the extent of the introduction could also be controlled. In vitro degradation speed of the hydrogel prepared by mixing of aldehyded dextran with ε-poly(L-lysine) at 37oC significantly varied by acetic anhydride concentration added to ε-poly(L-lysine) from < 5h to > 5 weeks. Bonding strength of the glue was 4 times higher than that of commercial fibrin glue and almost no cytotoxicity was observed, suggesting the development of novel self-degradable bioadhesive.