Nanobody-based polyvinyl alcohol beads as antifouling adsorbents for selective removal of tumor necrosis factor-α

Highly efficient removal of tumor necrosis factor-α (TNF-α) from plasma by hemoperfusion for autoimmune disease therapy remains a challenge in the clinical field owing to the low adsorption capacity and poor blood compatibility of adsorbents. In this work, a new class of nanobody (Nb)-coupled antifouling polyvinyl alcohol (PVA) beads was constructed as an immunosorbent for the selective removal of TNF-α from plasma. Notably, our immunosorbent exhibited an exceptionally high specific TNF-α adsorption capacity of 416.9 ng/g in human plasma (at a plasma-to-adsorbent ratio of 300). More importantly, the obtained adsorbent beads showed outstanding blood compatibility. In addition, during in vivo experiments, the blood circulation device was constructed to remove TNF-α in rat models, proving that the beads had good removal performance (∼85%/60 min). Furthermore, 95% of the original capacity was retained after 6-month storage, showed strong stability and prolonged storage of PVA-Nb. Above all, the results indicate that the novel PVA-Nb immunosorbent has possible clinical applications for treating autoimmune diseases in the clinic.