Plasma membrane recovery kinetics of a microfluidic intracellular delivery platform (1013.2)

Intracellular delivery of macromolecules continues to be a challenge in both research and therapeutic applications. Recently, physical delivery methods, such as electroporation and sonoporation, have emerged that provide direct access to the cytoplasm by disrupting the plasma membrane. For a rapid development of such methods the mechanisms behind their action need to be understood. We use the microfluidic shear-based CellSqueeze delivery platform to examine the kinetics of plasma membrane recovery after disruption and its dependence on the calcium content in the surrounding buffer. Delivery experiments with HeLa cells show that the pores close ten times faster when calcium is present in the surrounding buffer. If we eliminate calcium from the buffer, we are able to improve delivery efficiency five-fold without sacrificing cellular viability. Membrane repair characteristics initially observed in HeLa cells are shown to translate to primary naive murine T cells, suggesting that calcium may have a similar ro...