Sealing effect of rapidly curable gelatin-poly (l-glutamic acid) hydrogel glue on lung air leak

Background. Air leak is a problem commonly occurring in lung and thoracic operations. In this study, a rapidly curable hydrogel glue was prepared as the seal for lung air leak. Methods. Mixing an aqueous solution of gelatin and poly(l-glutamic acid) with a water-soluble carbodiimide produced a hydrogel. The sealing effect on the air leak wound of rat lung was compared with that of conventional fibrin glue. Results. The gelatin-poly(l-glutamic acid) hydrogel glue was solidified as rapidly as the fibrin glue, and was significantly more effective in sealing the lung air leak than the fibrin glue. Approximately 80% of the lungs treated with the hydrogel glue exhibited no air leak at the lung pressure of 50 cm H2O. Urea addition could prevent spontaneous gelatination of the mixed solution at room temperature and did not affect the hydrogel sealing effect. The bonding strength of the hydrogel glue both with and without urea to the lung tissue was significantly higher than that of the fibrin glue. Conclusions. We concluded that this strong lung adhesion of the gelatin-poly(l-glutamic acid) hydrogel glue resulted in its superior sealing effect.