Chromatographic techniques are widely used in the purification of biopharmaceutical compounds with high commercial value, such as monoclonal antibodies (mAbs). Although very robust, these processes require extensive and time-consuming optimization of operating conditions in a case-by-case basis, which is often a limiting factor in the speed-to-market. In this work, we developed a novel microfluidic platform comprising chromatography beads inside micro-columns (V = 210 nL) for rapid screening of operating conditions. Particularly, a chromatography multimodal ligand (Capto MMC) was studied for the capture and elution of a fluorescent conjugate mAb-Alexa 430 spiked in a real cell culture supernatant under a wide range of conductivity and pH conditions. Aiming at an integrated and automated approach, pneumatic valves were incorporated in the device allowing real-time monitoring of adsorption, elution, regeneration and equilibration of the microfluidic column, within 2-3 min total assay time per condition. Furthermore, the chromatography assay was combined with a signal acquisition module, comprising the fabrication and coupling of a-Si:H photodiodes with a fluorescence filter for high sensitivity fluorescence measurements at bead-level. The interaction ligand-mAb was further analyzed with respect to the individual contribution of the hydrophobic (-phenyl) and electrostatic (-carboxyl) ligand moieties in describing the binding mechanism. The microfluidic results were then validated at macroscale using commercially available pre-packed columns in standard chromatography assays. In summary, we report a versatile, scalable and inexpensive method to expedite chromatography screening studies, using reduced amounts of reagents (~50 μL), mAb molecules (~25 μg) and resin (~70 nL). This platform can also be extended to any type of chromatography beads and target molecule, after an appropriate labeling procedure.

Rapid optimization of chromatographic separations using a nano-liter scale column in a microfluidic platform

253rd National Meeting (2017)

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