Real-time and label-free monitoring of monoclonal antibody secretion rates using a PC-TIR biosensor

The growing demand for monoclonal antibodies (mAbs) in biomedical applications requires efficient biomanufacturing processes with real-time monitoring capabilities to maximize production outputs cost-effectively. Currently, mAb production monitoring relies on end-point assays that fail to capture the real-time dynamics of mAb secretion. This study introduces a novel integrated system combining a photonic crystal structure in a total-internal-reflection (PC-TIR) biosensor with a microtranswell chip for the label-free and real-time monitoring of mAb secreted by hybridoma cell lines. This bioassay system accurately detects immunoglobulin G (IgG) in solution diffusing from the microtranswell, through the porous membrane, and to the evanescent field above the biosensor's top layer, generating standard curves with R² > 0.99. Using W6/32 hybridoma cells, the biosensor monitors real-time mAb secretion rates with high sensitivity. Cell density and culture conditions, specifically fetal bovine serum (FBS) concentrations, correlate positively with mAb secretion rates. The biosensing platform can also differentiate mAb secretion rates among hybridoma clones raised against the same immunogen. The real-time monitoring capabilities of our novel platform offer a rapid, accurate, and scalable method for improving biomanufacturing processes and production of mAbs.