Results- The PNiPAAm+CII sub-freezing gel was synthesized using a sub-freezing gelation method and physiochemically characterized. The sub-freezing gel features highly micron-sized pores ranging from 81 to 237 µm, with interconnectivity that facilitates the easy flow of protein solutions or even whole blood through the column. Mechanical strength tests indicated that the sub-freezing gel could sustain flow under gravitational conditions, exhibiting a higher elastic Young’s modulus due to CII incorporation. Biocompatibility was confirmed through the MTT assay with MDCK fibroblast cells, demonstrating cytocompatibility in contact with the sub-freezing gel. The sub-freezing gel showed minimal binding of the blood cells upon incubation with blood cells indicating its suitability as an appropriate matrix for blood filtration. Interestingly, the sub-freezing gel-based column showed biological affinity for binding CII-specific autoantibodies present in serum of CIA mice. Remarkably, the sub-freezing gel column selectively captured CII-specific autoantibodies from the whole blood of CIA mice in a continuous run, without requiring processing steps like centrifugation or plasma separation, and without significantly retaining of the blood cells.
Conclusion- Current study introduces a novel macroporous sub-freezing gel-based column for the selective binding of antigen-specific antibodies from the whole blood of CIA mouse model. This represents a therapeutic potential in the future for the selective depletion of antigen-specific IgG, potentially managing inflammation in autoimmune diseases.