Preparation and Properties of Polydopamine Coated Modified Calcium Alginate/Polyacrylamide Anti-adhesive Hydrogel

Film and hydrogel materials are mainly used as anti-adhesion barriers to prevent intrauterine adhesions (IUA) after surgery, but the efficacy of materials currently used in clinical practice is still not satisfactory due to insufficient adhesion and rapid degradation. Calcium alginate/polyacrylamide (CA/PAM) double-network hydrogel has excellent mechanical properties and biocompatibility, which is suitable for anti- adhesion materials, but the adhesion is insufficient and easy to shift. In this paper, polydopamine (PDA) coating was used to modify the CA/PAM hydrogel, and PDA@CA/PAM hydrogel was prepared to improve its adhesion properties. The SEM images show that the PDA coating is successfully applied, and that the hydrogel has a good three-dimensional porous network structure. The mechanical property test showed that the hydrogel had excellent tensile and compressibility, which allowed it to enter the target location smoothly and withstand certain pressure. The lap-shear test demonstrated that the modification of PDA coating significantly improved the tissue adhesion properties of CA/PAM hydrogels. The swelling and degradation properties indicated that the hydrogel could absorb the wound exudate and keep it on the wound for a certain period of time. The introduction of PDA coating also improved the hydrophilicity of the hydrogel. Cytotoxicity tests and hemolysis experiments showed that the cell activity of hydrogel was above 80%, and the hemolysis rate was below 5%. Moreover, PDA@CA/PAM hydrogel showed higher cell compatibility and blood compatibility than that of CA/PAM.