Single cell polycationic coating for bioprocessing

Single cell encapsulation with a semi-permeable biodegradable shell is an attractive procedure for biomedical applications, including cell printing. Nozzle clogging is the major limitation of inkjet bioprinting, which makes the process unreliable. This work explored the use of poly-L-lysine (PLL), a polycation, on single cell coating for the development of reliable bio-inks. Coated cells had their viability, metabolism and genetic karyotype evaluated. The mechanism of coating release was studied using Transmission Electron Microscopy, and cell morphology by confocal microscopy. Coated and non-coated cells were printed at 1000 Hz cells per second using a modified inkjet bioprinter and the reliability assessed by printing droplets at 10-minute intervals over a one hour period, and subsequently counting cells.