A chitosan-optimized polyethyleneimine/polyacrylic acid multifunctional hydrogel for reducing the risk of ulcerative arterial bleeding

Ulcerative arterial bleeding is characterized by sudden onset, rapid disease development, and high mortality, which is a great challenge for clinicians to treat, specially bleeding in areas where endoscopic operation is difficult, or in the case of diffuse bleeding, tumor bleeding, and recurrent bleeding. Herein, we proposed a novel treatment strategy using biomaterials to protect the wound and isolate the erosion of digestive tract contents to prevent arterial bleeding in advance. By introducing chitosan to construct multihydrogen-bonding and an electrostatic interaction system, we developed polyethyleneimine/polyacrylic acid/chitosan (PEI/PAA/CS) multifunctional hydrogel. The new hydrogel is characterized by ultrafast gelation, strong tissue adhesion, gastric acid resistance, burst resistance, biocompatibility, hemostasis, and tissue repair. The addition of CS significantly improved the tissue adhesion, biocompatibility, hemostasis, and tissue repair ability of the hydrogel. The PEI/PAA/CS hydrogel could adhere to the ulcer surface and form a protective layer on the wound to prevent arterial bleeding. Importantly, the PEI/PAA/CS hydrogel also has the ability to stop bleeding and promote wound repair, which has been demonstrated in a variety of hemorrhage models in rats and rabbits. All of these factors indicate that the PEI/PAA/CS hydrogel is a promising biomaterial for reducing the risk of ulcerative arterial bleeding.