Generation of uniform-sized spheroids as 3D cancer models using simple and scalable PDMS-based microwell devices.

Cancer researchers now consider spheroids a valuable in vitro model for cancer research and personalized medicine. They are used to studying cancer development, testing drug effectiveness, and potentially guiding treatment decisions for individual patients. Spheroids represent the simplest form of three-dimensional (3D) cellular arrangement and encapsulate the essential tumor microenvironment. These characteristics are crucial for studying processes such as tumor invasion, metastasis, angiogenesis, and cell cycle kinetics. In particular, spheroids excel in chemo-response assays where traditional monolayer cell cultures often fall short. A PDMS microwell device was developed to generate uniform-sized cancer spheroids. This device is user-friendly and capable of producing a large number of spheroids. The device measures 13 mm in diameter (1200 microwells per well if the device has microwells 400 µm in size, and 300 microwells per well if the device has microwells 800 µm in size). It advances 3D cultures by requiring only a small volume of cell culture supplements and is easy to manage. The hydrophobic nature of the PDMS device prevents cells from adhering to it, thereby promoting spheroid formation. Spheroids can be created on microwell devices, and subsequent experiments may either be conducted on the device or transferred to cell culture dishes for additional 3D biological assays. Seeding cells is notably easier compared to other 3D cell culture techniques, and the number of cells in each spheroid can be adjusted according to specific requirements. Overall, the PDMS-based microwell device offers a simple and efficient means to produce large quantities of uniform-sized spheroids for 3D cell culture studies, showcasing high throughput, short generation times, long-term effectiveness, and ease of handling.