In Vivo Evaluation and Application of Adsorbents for Hemoperfusion

Hemoperfusion is a blood exchange transfusion and it has been one of the most efficient life-saving therapies to remove exogenous or endogenous toxins from the bloodstream in cases of uremia, hyperlipidemia, hyperbilirubinemia, endotoxemia, acute poisoning, etc. In most instances it refers to the extracorporeal blood circulation unit consisting chiefly of adsorbents. As the core aspect of hemoperfusion to achieve the desired therapeutic effect aimed at different states of patients, the adsorbent is expected to possess advantages of adsorption capacity, adsorption selectivity, hemocompatibility, etc. Various adsorbents have been developed for hemoperfusion in recent years. They are based on natural polymers, synthetic polymers, inorganic materials, metal–organic frameworks, porous aromatic frameworks, etc. A series of in vitro experiments have been conducted in studies on the evaluation of the cytotoxicity and blood compatibility of hemoperfusion adsorbents; generally, they covered tests of hemolysis, clotting time, blood routine, etc. Nevertheless, it is impossible to transfer these adsorbents from bench to bedside without conducting in vivo experiments, since most of these in vitro experiments implemented a simplified simulation of human pathology with a lack of complexity in clinical practice. Also, trials on human and non-human primates are confronted with ethical and social issues. Constructing an appropriate animal model can effectively predict the therapeutic success of novel adsorbents in clinical trials by simulating and replicating the physiological environment of the human body. This chapter discusses in vivo assays in animal models for hemoperfusion adsorbents and the artificial liver, and clinical applications of hemoperfusion and the artificial liver are also reviewed.