WAX PATTERNED PAPER-BASED MICROWELLS FOR 3D CELL CULTURE AND CRYOPRESERVATION

In this work, we develop a high-throughput paper-based culture platform for the growth and cryopreservation of arrays of independent and dense 3D cell clusters. Paper platforms demonstrated attractive properties to culture and cryopreserve cells. Indeed, the porous cellulose fiber network of filter papers-a biocompatible structure comparable to extracellular cell matrix-allows cells to naturally aggregate and form connections within the 3D environment, thus resulting in more complex signaling pathways than the flask-grown 2D cells. Papers can further be patterned, labeled, folded, rolled, and laminated, all of which facilitate firm, storage saving, and pragmatic cryopreservation of 3D cell tumor models. The method presented here relies on wax printing to encapsulate microwells within hydrophobic barriers, plasma treatment to enhance cell loading within the microwells, and 3D printing to produce a microfluidic device for precise and localized cell loading into the microwells. The simple and inexpensive paper-based platform opens door for various innovations in drug discovery, tissue engineering, and personalized medicine.