Flexible Catechol-Conjugated Chitosan/Gelatin Bilayer Patches for Topical Hemostasis in Laparoscopic Surgery

Recently, mussel-inspired catechol-conjugated chitosan (CHI-C)-based topical hemostats have been developed to arrest intraoperative bleeding in patients with coagulopathy through interactions between CHI-C and blood proteins. Pseudo-active blood coagulation, defined as material-assisted clot formation through CHI-C-blood protein complexation without exogenous coagulation proteins, is achieved using CHI-C/gelatin (CHI-C/Geln) bilayer structures. However, these bilayer hemostats still have limitations in laparoscopic surgical settings owing to their stiffness, which can impair trocar deliverability. In this study, we optimized CHI-C/Geln bilayer patches for laparoscopic surgical application by controlling patch thickness through compression. We prepared three types of CHI-C/Geln patches with thicknesses of 1, 3, and 5 mm to compare their tissue adhesiveness, mechanical properties, trocar deliverability, and hemostatic capability. The CHI-C/Geln patches with thicknesses of 1 and 3 mm could pass through 10-12 mm trocars without fragmentation during rolling or repeated folding. In addition, the 3-mm-thick CHI-C/Geln patches exhibited effective tissue adhesiveness, bursting pressure, and hemostatic ability. Thus, these flexible adhesive patches could serve as topical hemostats that function effectively in laparoscopic surgery.