In some examples, an apparatus can include a mating interface coupled to a dispense interface to interact with a print particle dispense nozzle, a locking mechanism coupled to the dispense interface to prevent the print particle dispense nozzle from depositing a print particle to the dispense interface, and an authentication mechanism coupled to the locking mechanism to: authenticate the print particle dispense nozzle, and unlock the locking mechanism when the print particle dispense nozzle is authenticated to allow the print particle dispense nozzle to deposit the print particle to the dispense interface.