Printing Biomimetic Hydrogel Scaffolds Using a Custom-Designed Micro-Extrusion Bioprinter

To begin, switch on the micro-extrusion pump controller. Select the corresponding volume syringe and set the extrusion rate at 0.08 milliliters per minute. Then divide the hydrogel volume by the extrusion rate and coordinate it with the desired printing time to calculate the duration of extrusion.

Next, fit the syringe with a needle featuring an inner diameter of 210 micrometers into the syringe slot of the bioprinter. Adjust the syringe controller to ensure that the plunger of the syringe is in close contact with the screw. Then place three milliliters of the prepared kappa-carrageenan suspension bath into a 35 millimeter cell culture dish.

Based on the code settings, position the dish on the platform and confirm that the printing head is one millimeter above the bottom of the dish. After that, insert the SD card containing the code into the 3D bioprinter. Activate the code file, start the bioprinter, and click the Start button on the controller.

Then expose the printed construct to 405 nanometers of blue light for one minute to initiate photo-crosslinking. Using a one milliliter pipette, remove the kappa-carrageenan gel, followed by the addition of three milliliters of PBS for washing and subsequent removal.