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.