Preparation and characterization of hyaluronic acid-based fixable materials for prevention of postsurgical adhesion

Postsurgical adhesions are frequent complications of surgical procedures that cause significant morbidity in patients. Hyaluronic acid (HA)-based anti-adhesive materials prevent postsurgical adhesion; however, fixation of these materials at the surgical site remains an issue. In this study, we developed HA-based, fixable, self-healing materials to prevent postsurgical adhesions. Gallic acid-conjugated hyaluronic acid (HA-GA) was synthesized using adipic acid dihydrazide linkers and mixed with HA solution to prepare HA/HA-GA mixtures as fixable anti-adhesive materials. The HA/HA-GA mixtures with the 7:3 v/v ratios exhibited optimized elastic modulus (G′) values (1.97 ± 0.02 kPa) that were higher than those of the unmodified HA (12.6 ± 2.86 Pa) and lower than those of HA-GA (10.8 ± 1.70 kPa). In addition, in vitro immobilization experiments demonstrated that while HA alone flowed down a vertically oriented porcine intestinal surface within 1 min, the HA/HA-GA blend remained in place for the entire observation period (7 min). Moreover, the HA/HA-GA mixtures (7:3 v/v ratio) yielded markedly lower adhesion scores (1.3) than those of the control (5.3) and HA/HA-GA mixtures with a 9:1 v/v ratio (3). Thus, the HA/HA-GA mixture can be exploited as an anti-adhesion agent that effectively prevents postsurgical adhesion by immobilizing HA/HA-GA anti-adhesives at the surgical site and forming physical barriers.