Apparatus for efficient genetic modification of cells

A method for activating cells with activation particles, the method comprising:

• introducing a fluid with the cells and the activation particles into a first flow chamber through a first port, such that the fluid, the cells, and the activation particles contact a semi-permeable membrane having a plurality of pores dimensioned to allow passage of the fluid and prevent passage of the cells and the activation particles;
• flowing the fluid in a first direction through the semi-permeable membrane at a first flowrate, the first flowrate being between 0.1 ml/min/cm2 and 1.0 ml/min/cm2 per surface area of the semi-permeable membrane, and selected responsive to one or more of number of cells introduced, device geometry, and cross-sectional area of the semi-permeable membrane;
• discharging the fluid through a second port;
• incubating the cells in the first chamber while the cells become substantially activated;
• introducing a recovery fluid into a second flow chamber opposite the first flow chamber, through the second port;
• flowing the recovery fluid in a second direction through the semi-permeable membrane at a second flowrate, the second flowrate being between 0.5 ml/min/cm2 and 1.5 ml/min/cm2 per surface area of the semi-permeable membrane, and selected to maintain an average wall shear stress between 0.05 Pa and 1.5 Pa;
• and
• discharging the recovery fluid with the cells and the activation particles through a third port.