Abstract: Disclosed is a method for producing genetically engineered cells in vitro. The method includes direct injection of a genome editing composition into a cell nucleus of a cell. The genome editing composition includes at least one Cas protein and at least one gRNA molecule to target a distinct genomic location. The injection is performed with a microelectromechanical systems injection chip including a cantilever. The cantilever includes a microchannel being in fluid communication with a nanosyringe, and wherein direct injection includes providing a fluid communication between the microchannel and the nucleus of the cell by insertion of the nanosyringe into the nucleus of the cell and injecting the genome editing composition via the microchannel through the nanosyringe into the nucleus of the cell.