This paper describes a methodology of photopolymer mold fabrication with multi-level microstructures for polydimethylsiloxane (PDMS) microfluidic device manufacture.

A perfusion microfluidic device to culture adherent eukaryotic cells for the production of monoclonal antibodies with potential for therapeutic use.

Conventional manufacturing methods for polydimethylsiloxane (PDMS)-based microdevices require multiple steps and elements that increase cost and production time. Also, these PDMS microdevices are mostly limited to single use, and it is difficult to recover the contents inside the microchannels or perform advanced microscopy visualization due to their irreversible sealing method. Herein, we developed a novel manufacturing method based on polymethylmethacrylate (PMMA) plates adjusted using a mechanical pressure-based system. One conformation of the PMMA plate assembly system allows the reproducible manufacture of PDMS replicas, reducing the cost since a precise amount of PDMS is used, and the PDMS replicas show uniform dimensions. A second form of assembling the PMMA plates permits pressure-based sealing of the PDMS layer with a glass base. By reversibly sealing the microdevice without using plasma for bonding, we achieve chip on/off configurations, which allow the user to open and close the device and reuse it in an easy-to-use way. No deformation was observed on the structures of the PDMS microchannels when a range of 10 to 18 kPa pressure was applied using the technique. Furthermore, the functionality of the proposed system was successfully validated by the generation of microdroplets with reused microdevices via three repetitions.

To produce innovative biopharmaceuticals, highly flexible, adaptable, robust, and affordable bioprocess platforms for bioreactors are essential. In this article, we describe the development of a large-area microfluidic bioreactor (LM bioreactor) for mammalian cell culture that works at laminar flow and perfusion conditions. The 184 cm² 32 cisterns LM bioreactor is the largest polydimethylsiloxane (PDMS) microfluidic device fabricated by photopolymer flexographic master mold methodology, reaching a final volume of 2.8 mL. The LM bioreactor was connected to a syringe pump system for culture media perfusion, and the cells’ culture was monitored by photomicrograph imaging. CHO-ahIFN-α2b adherent cell line expressing the anti-hIFN-$a$2b recombinant scFv-Fc monoclonal antibody (mAb) for the treatment of systemic lupus erythematosus were cultured on the LM bioreactor. Cell culture and mAb production in the LM bioreactor could be sustained for 18 days. Moreover, the anti-hIFN-$a$2b produced in the LM bioreactor showed higher affinity and neutralizing antiproliferative activity compared to those mAbs produced in the control condition. We demonstrate for the first-time, a large area microfluidic bioreactor for mammalian cell culture that enables a controlled microenvironment suitable for the development of high-quality biologics with potential for therapeutic use.