Determination of cell density, shear stress, productivity, and biological activity of monoclonal antibodies cultured in microfluidic devices

LERNER B.; OGGERO, MARCOS; HELGUERA G.; ATTALLAH C.; PEÑAHERRERA A. B.; BOURGUIGNON N.; PÉREZ M. S.; BOOTH, ROSS; KARP P.

Buenos Aires

Congreso; IV International Congress in Translational Medicine; 2018

Facultad de Farmacia y Bioquímica, UBA

The production of recombinantmonoclonal antibodies (mAbs) for therapeutic use is an expanding area of the biopharmaceuticalindustry. However, the traditional production in bioreactors faces challengesrelated to the quality of product, glycosylation and reproducibility. Oneapproach to optimize the process and improve the quality of product is toreduce the scale of the cell culture through microfluidic devices. In this workis presented a PDMS/glass microfluidic device with sequential cisterns in fourmicrochannels for culture of mAb expressing cells. First, we evaluated the conditionsfor seeding CHO-K1 (Chinese Hamster Ovary) cells in the microfluidic device. After seeding with 2x105 cells/mL in the device, weobserved a homogeneous distribution, achieving cell monolayer of 620 cells/ mm2at day 7 of culture. The Comsol 5.2a software package wasused to simulate flow velocity and shear stress in the microchannels.The computational 3D simulation showed that the configuration of themicrochannels provided an optimally distribution of the fluid across the cellculture surface. Thecalculated maximumvelocity magnitude of 2 m/s was observed the center of the channels, but in thecisterns it was estimated at 0.5 m/s. The calculated shear stress shows values of 0.1 to 0.6 Pafor the cisterns and the microchannels respectively. These values are withinthe observed in the physiologicalenvironment, suitable to sustain successive cycles ofcell culture without the need for a new inoculation. The productivity inthe microfluidic device was evaluated in two cell lines CHO-K1 and HEK293(Human Embryonic Kidney) that express the mAb anti-IFN-α2b. This mAb is a scFv-Fc minibody developedfor the treatment of Systemic Lupus Erythematosus. Cells were able to grow,reaching confluence and covering the total area of the device. The culture formAbs production in the microdevice was extended for 18 days. The production of Mabspresent in cell culture supernatant was evaluated by indirect ELISA, whichallowed the estimation ofoverall productivity of anti‑hIFN‑α2b per cell in the microchips using bothcell lines. Interestingly, the productivity in the microchips was up to 7.5fold higher compared to that obtained in T‑flasks run in parallel. Moreover,functional analysis of biological activity the MAbs produced in the deviceshowed no significant differences in the neutralizing antiproliferativeactivity of the hIFN‑α2b or the cytokine cell signaling compared to the MAbsproduced by standard methods, suggesting that expression of these recombinantproteins in the microdevices do not affect their functional attributes. Theseresults show that cell lines can be cultured in microfluidic devices inmonolayer, with low shear stress, with significantly higher productivity comparedto standard culture conditions, without affecting quality attributes of theproduct. These observations suggest that microfluidic devices could be aninteresting option for development of mAbs and other recombinant proteins withpotential for therapeutic use.