Categories, Characteristics, and Applications of Adsorbents for Blood Purification

For over 50 years, the field of blood purification has been focused on membrane-based technology, and hemodialysis has been a mature technique used to sustain the lives of patients with kidney failure. With a better understanding of pathogenic molecules that exist in human blood, blood purification therapy has been found to be applicable to an increasing number of diseases. A range of targets have been proposed to be eliminated from the blood circulation and physiological fluids, including various drugs, toxins, bioactive lipids, inflammatory mediators such as cytokines, free hemoglobin, immunoglobulins, immune complexes, and so on, which are very heterogeneous in molecular size, physicochemical properties, biological activity, and blood levels. Dialysis has inherent limitations for its size-based separation mechanism. Adsorption technology helps to address this shortcoming by removing toxic molecules largely untouched by dialysis technology. In addition, adsorbents that are based on molecular recognition also have special merits in binding capacity and safety. This chapter describes the classification, characteristics, and applications of adsorbents for blood purification. The main considerations for the design of the adsorbents, including biocompatibility and binding capacity, are emphasized as the primary factors associated with their safety and effectiveness.