Carbon nitride reinforced chitosan/sodium alginate hydrogel as high-performance adsorbents for free hemoglobin removal in vitro and in vivo.

Removing free hemoglobin generated during extracorporeal circulation remains a challenge. Currently, there is no adsorbent with specificity and good biosafety for removing hemoglobin. In this study, a new chitosan/sodium alginate/carbon nitride (CS/SA/CN) hydrogel adsorbent was prepared by blending SA with CN to drop into CS/CaCl solution. The physicochemical properties of CS/SA/CN hydrogel were evaluated using some techniques, including scanning electron microscope, Zeta potential measurement, and thermogravimetric analysis. Hemoglobin adsorption in vitro, stability, hemocompatibility, cell compatibility, inflammatory reaction and blood extracorporeal circulation in vivo were also evaluated. The findings revealed that the CS/SA/CN-0.4 % hydrogel exhibited an impressive adsorption capacity of 142.35 mg/g for hemoglobin. The kinetic data of hemoglobin adsorption were well-described by pseudo second-order model, while the isothermal model data conformed to the Langmuir model. The hardness and modulus of CS/SA/CN-0.4 % was 11.7 KPa and 94.66 KPa respectively, which indicated robust resistance to breakage. CS/SA/CN demonstrated excellent hemocompatibility, biocompatibility and anti-inflammatory properties. In addition, the results of in vivo rabbit extracorporeal blood circulation experiment demonstrated that CS/SA/CN could adsorb free hemoglobin from blood while maintaining high biosafety standard. Consequently, CS/SA/CN hydrogel emerges as a promising candidate for use as a hemoglobin adsorbent in extracorporeal blood circulation system.