Nanobody-Based high-performance immunosorbent for selective beta 2-microglobulin purification from blood

Area of Science:

• Biomaterials Science
• Immunology
• Nephrology

Background:

• Dialysis-related amyloidosis (DRA) is a serious complication in end-stage kidney disease patients, linked to beta2-microglobulin (β2M) accumulation.
• Current extracorporeal blood purification methods for β2M removal lack sufficient specificity, capacity, or are cost-prohibitive.
• Nanobodies (Nbs) offer advantages over traditional antibody fragments for developing highly specific and efficient immunosorbents.

Purpose of the Study:

• To develop and characterize a novel, cost-effective, and highly efficient immunosorbent for β2M removal.
• To evaluate the capacity, specificity, reusability, and storage stability of the anti-β2M nanobody immunosorbent.
• To assess the potential clinical applicability of the developed immunosorbent for immunoadsorption therapy in dialysis patients.

Main Methods:

• Preparation of an anti-β2M nanobody with a C-terminal thiol-tag from E. coli.
• Site-directed and oriented immobilization of the nanobody onto a support matrix to create a β2M-selective immunosorbent.
• In vitro evaluation of binding capacity, specificity against other serum proteins, regeneration efficiency, and storage stability.

Main Results:

• The developed immunosorbent demonstrated a high binding capacity of up to 7 mg β2M per mL resin, 17 times higher than previous studies.
• Exceptional specificity was observed, with no significant adsorption of other human serum proteins.
• The immunosorbent retained 80% of its capacity after four regeneration cycles and 90% after one month of storage.

Conclusions:

• The novel anti-β2M nanobody immunosorbent is a practical, economic, and highly effective solution for β2M removal.
• Its high capacity, specificity, reusability, and stability support its potential for clinical application in immunoadsorption therapy.
• This development represents a significant advancement in managing dialysis-related amyloidosis.