It is a very subjective question and would depend highly on the device type and cells. Please ask for help your senior lab members and technical person who desigb or have already worked with the chip.
In order to avoid shear stress, you can create a mixture of hydrogel and cells. This will minimize cell rupture when passing through tubing and small channels.
Most microfluidic devices allow the injection of cells using a pipette directly.
Please, let me know if there is anything else I can help you with.