Rapidly curable biological glue composed of gelatin and poly(image-glutamic acid)

The tissue adhesion property of a hydrogel cross-linked with water-soluble carbodiimide (WSC) was investigated and compared with that of the conventional fibrin glue. The biodegradable hydrogel was composed of gelatin and poly(image-glutamic acid) (PLGA). This study focussed on the mouse skin bonding by the WSC-formed hydrogel prepared from a low-molecular-weight (Mw) gelatin whose aqueous solution did not spontaneously set to a gel at 25 °C, in contrast to the conventional gelatin with high Mw. At polymer concentrations lower than the incipient gelation concentration, the bonding strength of mouse skin by the WSC-cross-linked gelatin-PLGA hydrogel increased with an increase in the concentration of gelatin and PLGA, irrespective of Mw of gelatin. When compared at the highest gelatin concentration which did not cause gelation, the bonding strength of the hydrogel composed of lower Mw gelatin and PLGA was higher than that of higher Mw gelatin hydrogel with or without PLGA or the conventional fibrin glue. The mixed aqueous solution from the gelatin with Mw of 10000 and PLGA was gelled by use of WSC as rapidly as the fibrin glue. It was concluded that the gelatin-PLGA hydrogel is a safe biological glue with the adhesion property superior to the fibrin glue.