A Serial Copolymerization Procedure for Manufacturing Immunoadsorption Walls as a Potential Unit in Conjunction With Hemodialysis Filters

A novel recyclable hemoperfusion adsorbent based on TiO2 nanotube arrays for the selective removal of β2-microglobulin

Prolonged and excessive accumulation of β2-microglobulin (β2m) in the blood can lead to various kidney-related and other diseases. Currently, the most effective method of removing β2m from the blood is hemoperfusion. Although some traditional hemoperfusion adsorbents such as cellulose and polystyrene microspheres have been used for the removal of β2m, their selectivity still needs improvement. Immunosorbents have been developed to address this issue, but high cost and limited application are concerns. TiO2 nanotube arrays (TNTAs) have shown great potential in adsorption-related biomedical applications. In this study, we designed and developed a novel TNTA-based hemoperfusion adsorbent for the removal of β2m, which has demonstrated good biocompatibility, selectivity, and reusability. We investigated the β2m adsorption capacities of TNTAs with different pore sizes. The results indicate that TNTAs with a pore size matching the size of β2m exhibit higher adsorption capacity while also having lower adsorption capacity for albumin, showing the importance of pore size on the selectivity of adsorbents. Additionally, green regeneration of TNTAs is achieved via the photocatalytic activity originating from TiO2. Even after five cycles, the adsorption capacity of TNTAs remained above 70%. Our work demonstrates that inorganic materials with ordered pores are capable to be candidates for hemoperfusion, possessing advantages over traditional organic materials such as high stability, security, and low cost.

New Ligand Coupling Procedure for Formation of an Immunoadsorption Wall

To prevent the occurrence of dialysis-related amyloidosis, an immunoadsorption wall based on polyacrylamide has been manufactured by a recently developed, partially incomplete, two-stage polymerization method. During the preparation process, efficient utilization of coupling antibodies is the key to large-scale production of such a toxin removal modality. In this study, we attempted to carry out the ligand coupling procedure after formation of a cyanogen bromide (CNBr)-activated stationary phase, using anti-beta2-microglobulin (beta-2M) antibodies. In vitro immunoadsorption tests show that the levels of beta-2M decrease rapidly within the first 2 hours for all the immunoadsorption tests. After that, nearly blank values were reached for tests of initial levels of c. 30 microg/mL and c. 82 microg/mL, whereas a relatively constant level of c. 10 microg/mL was maintained for the test of initial levels of c. 185 microg/mL. The maximum surface binding capacity of the prepared immunoadsorption walls is estimated by fitting experimental data, using a mathematical model of saturation kinetics. The present comparative investigation also suggests the manufacturing process for an immunoadsorption wall could be improved and facilitated by this new ligand coupling procedure without compromising the resulting binding capacity. Furthermore, the experimental protocols as well as the present methodology could be helpful for development of a clinically applicable immunoadsorption wall.