Hemoperfusion Adsorbents for Removal of Common Toxins in Liver and Kidney Failure: Recent Progress, Challenges, and Prospects

Abstract

Liver and kidney failure can lead to extensive accumulation of toxic metabolites in the blood and tissues, such as bilirubin, blood ammonia, endotoxins, cytokines, creatinine, uric acid, and urea, which aggravate the progression of the disease. Hemoperfusion can effectively adsorb and remove toxins from the blood and treat liver and kidney failure. However, the adsorption efficiency and safety of traditional hemoperfusion adsorbents are not ideal. Thus, it is urgent to develop new toxin adsorbents with good blood compatibility, as well as high adsorption and strong selective capacities, to fulfill the growing clinical needs. In recent years, new hemoperfusion adsorption materials that can improve the adsorption performance of blood toxins while maintaining good blood compatibility have been developed, with promising potential for clinical applications. This review classifies and summarizes the recent research progress in hemoperfusion adsorbents for common blood toxins (bilirubin, blood ammonia, endotoxins, cytokines, creatinine, uric acid, and urea) produced by liver and kidney failure. The composition and structure of various toxin adsorbents, toxin adsorption performance, biocompatibility, blood safety, and the mechanisms of toxin adsorption are discussed. Based on a summary of recent studies, feasible strategies have been explored for designing and preparing hemoperfusion adsorbents to fulfill future development requirements. The trends and clinical application prospects of various toxin adsorbents are also discussed.This article is protected by copyright. All rights reserved

Metal–organic framework-based adsorbents for blood purification: progress, challenges, and prospects

“…46,64 Between those toxins and MOFs, the interactions refer to van der Waals forces, electrostatic forces, charge transfer effects, (acid/base interactions, p-p conjugation, coordination bonds, and hydrogen bonds), and ion exchange. 17 Also, in practical blood purification, there can exist multiple toxins, along with complicated competitive adsorption. For example, Yıldız et al adopted grand canonical Monte Carlo (GCMC) simulations to analyze the urea/creatine adsorption model in bio-MOF.…”

“…The adsorption behavior of MOFs is correlative to the toxin types. 17 The chemical structures of the most commonly studied toxins adsorbed by MOFs are listed in Fig. 5(a).…”

“…3,[14][15][16] In both HD and HP, adsorbing materials are applied and play critical roles in toxin clearance. [17][18][19] For example, currently reported HD membranes are normally mixed matrix membranes (MMMs), consisting of sorbent fillers and polymeric matrix. 4,11,12 Via the synergistic effect of ultrafiltration and adsorption, toxic molecules are cleared more thoroughly.…”

“…This is because most adsorbents, such as activated carbons (ACs), lack defined pore channels for trapping certain toxic molecules and specific binding sites for further attraction. 17,22,23 Moreover, the blood environment is so complex that the development of adsorbents with good hemocompatibility, i.e., no hemolysis, no coagulation, and no complement activation, still faces significant challenges.…”

Reusable Zwitterionic Porous Organic Polymers for Bilirubin Removal in Serum

“…Bilirubin is a normal metabolite of hemoglobin, but it can be accumulated in the blood of patients with severe liver diseases, such as liver failure. , The excessive bilirubin can be transported and deposited in the main organs and nervous systems through blood circulation, causing various symptoms, including coma, epilepsy, mental retardation, brain damage, and even death. , Adsorption-based hemoperfusion, also called “artificial liver”, is a life-saving therapy to reduce the bilirubin level in these patients. − Activated carbon and resin are two major hemoadsorbents used to adsorb bilirubin clinically . However, they are troubled with the problems of low adsorption efficiency, protein fouling, and limited hemocompatibility. − To solve these problems, we have developed metal–organic framework (MOF)-based hemoadsorbents which showed high bilirubin removal, low protein adsorption, and excellent hemocompatibility. , However, considering the stability problems of MOFs, they cannot be used as reusable hemoadsorbents.…”