Performance evaluation of Mimetic Ligand™ B14-triazole-FractoAIMs adsorbents for the capture of human monoclonal immunoglobulin G from cell culture feed.

The new affinity-type Mimetic Ligand™ B14 was coupled with a 1,2-diaminoethane spacer (2LP) and a [1,2,3]-triazole spacer (TRZ) to three different support media. In addition to the agarose-based PuraBead and the polymethacrylate-type Fractogel, three new polymeric support media were introduced, the FractoAIMs 1, 2, and 3 (FA1, FA2, and FA3). These new FA supports differ in pore size as well as density of epoxide groups. The immobilization of the B14-ligand onto an azide-group-modified surface was performed with a copper (I)-mediated Click reaction. The IgG capture performance was tested for various ligand-spacer support combinations using cell culture feed containing human immunoglobulin G(1) (hIgG(1)). The most promising adsorbent, B14-TRZ-FA3, was further optimized by improving the surface chemistry through a triple endcapping concept employing an improved Click reaction protocol. This new technique enabled the most efficient deactivation of residual azide groups. In a direct comparison with a commercially available Protein A media, B14-TRZ-FA3 3× ec provided superior results at fast flow-rates and low bed-height. Dynamic binding capacities of 11.4 g/L for 10% breakthrough of hIgG(1), elution capacities of 16.0 g/L hIgG(1) and a recovery of 86% were achieved. The same results were obtained for a dialyzed and pre-purified feed solution, which is a clear indicator that triple-endcapped affinity support surfaces are practically inert to the non-specific binding of host cell proteins.