Provided herein are methods and apparatuses for transfecting a cell with a compound of interest by stressing the cell, e.g. with shear stress. The compound of interest may be nucleic acids, proteins, molecules, nanoparticles, drugs, etc., or any combination thereof. Methods of printing cells with an inkjet printing device are also provided, wherein at least a portion of viable cells (preferably at least 1%) are transfected with a compound of interest. Preferably, at least 25% of the cells are viable after printing. In addition, methods of forming an array of viable cells are provided wherein at least a portion of the viable printed cells (preferably at least 1%) are transfected with at least one compound of interest.
