Hypoxic Culture of Osteosarcoma Cells in PDMS Microfluidic Chamber and Plastic Bag

Drug uptake into tumor cells is critical for therapeutic efficacy, and chemoresistance is a limiting factor in therapeutic success. Chemoresistance and tumor growth are modulated by hypoxia, a state of oxygen deprivation. To understand the role of hypoxia in chemoresistance, simple and user-friendly experimental reproducibility of hypoxic conditions is crucial. Therefore, hypoxic culture in a microfluidic chip needs to be more easily controlled with reduced manual intervention, ensuring the precision required in a microchip device. This paper reports hypoxic and normoxic cultures of osteosarcoma cells in a microfluidic chip and plastic bag. Cells in microfluidic chips and glass bottom dishes were compared in terms of cell health, cell length, and density. SAOS-2 cells in hypoxic culture had an average length of 18.6 µm for PDMS chips, while in all other cases, the average cell length was approximately 80 µm. Cell density also showed similar results with PDMS chips under hypoxia having the lowest cell density of 30 cells/mm2. The results indicated that the PDMS material was effective in replicating a hypoxic condition of the tumor microenvironment compared to the traditional approach. This study using a PDMS chip and plastic bag serves as a proof of concept for a lab-on-a-chip approach to evaluate tumor growth factors that mimic the tumor environment.