Abstract
To develop adsorbents for the specific removal of tumor necrosis
factor-α (TNF) in extracorporeal blood purification, cellulose
microparticles were functionalized either with a monoclonal anti-TNF
antibody (mAb) or with recombinant human antibody fragments (Fab). The
TNF binding capacity of the adsorbents was determined with in vitro
batch experiments using spiked human plasma (spike: 1200 pg TNF/mL; 1
mg particles in 250 μL plasma). Random immobilization of the full-sized
monoclonal antibody to periodate-activated cellulose yielded particles
with excellent adsorption capacity (258.1 ± 48.6 pg TNF per mg adsorbent
wet weight). No leaching of antibody was detectable, and the adsorbents
retained their activity for at least 12 months at 4 °C. We found that
the conditions used during immobilization of the antibody (pH, nature of
the reducing agent) profoundly influenced the biocompatibility of the
resulting adsorbents, especially with respect to activation of the
complement system. Particles obtained by random immobilization of the
monovalent Fab fragments on periodate-activated cellulose using the same
conditions as for immobilization of the mAb exhibited only low
adsorption capacity (44 ± 7 pg/mg adsorbent wet weight). Oriented
coupling of the Fab fragments on chelate-epoxy cellulose via a
C-terminal histidine tag, however, increased the adsorption capacity to
178.3 ± 8.6 pg TNF/mg adsorbent wet weight. Thus, in the case of small,
monovalent ligands, the orientation on the carrier is critical to retain
full binding activity.
Original language | English |
---|---|
Pages (from-to) | 1864-1870 |
Journal | Biomacromolecules |
Volume | 6 |
Issue number | 4 |
DOIs | |
Publication status | Published - 2005 |
MoE publication type | A1 Journal article-refereed |
Keywords
- immobilization
- antibodies
- blood
- adsorbents
- cancer