Enhanced Sealing by Hydrophobic Modification of Alaska Pollock-Derived Gelatin-Based Surgical Sealants for the Treatment of Pulmonary Air Leaks

Pulmonary air leaks are medical complications of thoracic surgery for which fibrin sealant is the main treatment. In this study, innovative sealants based on hydrophobically modified Alaska pollock- derived gelatin (hm-ApGltn) and a poly(ethylene) glycol-based 4-armed cross-linker (4S-PEG) have been developed and their burst strengths have been evaluated using fresh rat lung. The developed sealants show higher lung burst strength compared with the nonmodified original ApGltn (Org-ApGltn)-based sealant and a commercial fibrin sealant. The maximum burst strength of the hm-ApGltn-based sealant is 1.6-fold higher than the Org-ApGltn-based sealant (n = 5, p < 0.05), and 2.1-fold higher than the commercial fibrin sealant (n = 5, p < 0.05). Cell culture experiments show that modification of ApGltn with cholesteryl or stearoyl groups effectively enhances anchoring to the cell surface. In addition, binding constants between hm-ApGltn and extracellular matrix proteins such as fibronectin and fibrillin are increased. Therefore, the new hm-ApGltn/4S-PEG-based sealant has the potential for applications in thoracic surgery.