Integrated 3D microstructured digital microfluidic platform for advanced 3D cell culture

Three-dimensional (3D) cell culture systems better simulate the in vivo microenvironment by promoting intercellular interactions and functional expression, which are crucial for tissue engineering and regenerative medicine. However, conventional two-dimensional (2D) culture platforms fail to mimic the spatial complexity of in vivo tissues, often resulting in altered cellular behavior and limited physiological relevance. In this research, we introduce a 3D cell culture platform based on a digital microfluidic (DMF) system. This platform integrates DMF electrode actuation with 3D-printed microstructure arrays, enabling precise capture and aggregation of cells within a defined 3D scaffold. While cells initially adhere in a 2D structure, they rapidly self-assemble into a 3D cell spheroid on the chip. The platform's capabilities for droplet dispersion, fusion, and movement were validated using the 3D-printed DMF chip. The key parameters, such as applied voltage, microstructure height, and electrode spacing, were systematically investigated for their effects on droplet manipulation. Cell viability and proliferation assays in 24, 48, and 72 hours confirmed that the 3D microstructured scaffolds exhibit excellent biocompatibility and provide a microenvironment favorable for in vivo-like cell growth. Overall, this integrated DMF chip supports robust 3D cell growth and represents a versatile tool for applications in tissue engineering and regenerative medicine.