Rapidly curable biological glue composed of gelatin and poly(L-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(L-glutamic acid) (PLGA). This study focussed on the mouse skin bonding by the WSC-formed hydrogel prepared from a low-molecular-weight (<(M)over bar w>) gelatin whose aqueous solution did not spontaneously set to a gel at 25 degrees C, in contrast to the conventional gelatin with high <(M)over bar w>. 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 <(M)over bar w> of gelatin. When compared at the highest gelatin concentration which did not cause gelation, the bonding strength of the hydrogel composed of lower <(M)over bar w> gelatin and PLGA was higher than that of higher <(M)over bar w> gelatin hydrogel with or without PLGA or the conventional fibrin glue. The mixed aqueous solution from the gelatin with <(M)over bar w> of 10 000 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. (C) 1996 Elsevier Science Limited