A Digital Microfluidic Platform for the Microscale Production of Functional Immune Cell Therapies

Abstract Genetically engineering human immune cells has been shown to be an effective approach for developing novel cellular therapies to treat a wide range of diseases. To expand the scope of these cellular therapies while solving persistent challenges, extensive research and development is still required. Electroporation has recently emerged as one of the most popular techniques for inserting biological payloads into human immune cells to perform genetic engineering. However, several recent studies have reported that electroporation can negatively impact cell functionality. Additionally, the requirement to use large amounts of cells and expensive payloads to achieve efficient delivery can drive up the costs of development efforts. Here we use a digital microfluidic enabled electroporation system (referred to as triDrop) and compare them against two state-of-the-art commercially available systems for the engineering of human T cells. We describe the ability to use triDrop for highly viable, highly efficient transfection while using substantially fewer cells and payload. Subsequently, we perform transcriptomic analysis on cells engineered with each of the three systems and show that electroporation with triDrop lead to less dysregulation of several functionally relevant pathways. Finally, in a direct comparison of immunotherapeutic functionality, we show that T cells engineered with triDrop have an improved ability to mount an immune response when presented with tumor cells. These results show that the triDrop platform is uniquely suited to produce functionally engineered immune cells while also reducing the costs of cell engineering compared to other commercially available systems.