Bioprinting GelMA

Overview

GelMA (gelatin methacrylate) is a gelatin-based hydrogel that reacts and crosslinks in the presence of LAP and Allevi blue light technology (1,2). The recommended preparation provided in the user instruction below yields a streamlined matrix bioink that supports 3D bioprinted cell-laden constructs. However, preparation can be modified by users to suit their needs. Follow this step-by-step guide for bioprinting gelMA in your lab.

Materials

·         LAP

·         Cell media

·         GelMA

·         Plastic syringe (5mL or 10 mL)

·         Syringe filter

·         Syringe coupler

·         Petri dish or well plate for printing

·         Optional: Glass slide (glass slide treatment protocol)

Methods

1. Mix LAP in 3 ml of PBS or cell media at 60°C under stirring to create a 0.5% w/v LAP concentration. Mix until all LAP is dissolved.
2. Add GelMA to solution to create a 10% w/v concentration. Mix at 60°C under stirring until all GelMA is dissolved. Be sure the container is tightly sealed while mixing to avoid evaporation of solution.
3. Keep GelMA at 60°C  and filter with syringe filter under sterile conditions.
4. In a sterile environment, cool solution to 37°C and load into syringe A.
5. Under sterile conditions and while solution in syringe A is still at 37°C, load concentrated cell solution into syringe B and mix with solution in syringe A using a syringe coupler. Be sure to mix thoroughly to create a homogenous solution. 
6. Once solution is thoroughly mixed, transfer entire mixture to syringe A, then remove syringe B from syringe couple and replace with an empty syringe (syringe C). Transfer entire solution to syringe C. 
7. Remove syringe coupler and place plastic bioprinting tip (Guide to Picking Your Bioprinting Needle) on syringe C, then load into the Allevi bioprinter. 
8.  Cool extruder until bioink reaches 22°C.
9. Prepare your design file on the Allevi software and use the print settings outlined below.

Print Settings

*Critical step: Your needle can have significant effects on print settings. Be sure to use the suggested needle type or re-calibrate print parameters.

Crosslinking settings

During Print

Post-print

Notes

1. Issues with gelMA bioprinting? Check out our Troubleshooting Guide. 
2. Gelation time and gel stiffness can be adjusted by varying the concentration of GelMA or LAP. For help adjusting print parameters please contact support@allevi3d.com.
3.  A fill volume change of more than 2 ml may affect pressure settings.

 A lower gauge size or tapered gauge will require a lower pressure, while a higher gauge will require a higher pressure for extrusion. Lowering the gauge size will also generally lower resolution