Poster L17 - Using a Modified 3D Plastic Printer for Bioprinting of Gelatin Methacryloyl and Agarose Tissue Scaffolds

Saturday, October 26, 2024

10:00 AM - 11:00 AM EST

Location: Exhibit Hall E, F & G

Presenting Author(s)

Catherine L. Mojazza

Undergraduate Student
The Pennsylvania State University
Plano, Texas, United States

Co-Author(s)

AS

Alyssa Salazar

Graduate student
The Pennsylvania State University
University Park, Pennsylvania, United States

Primary Investigator(s)

Justin L. Brown, PhD (he/him/his)

Professor
The Pennsylvania State University
University Park, Pennsylvania, United States

Introduction: Bioprinting using hydrogel-based bioinks is an emerging technique being explored for construction of cell-laden matrices for tissue engineering applications. Hydrogels are a common biomaterial used for bioprinting because of their favorable biocompatibility properties and similarities to the human tissue extracellular matrix (ECM). Current techniques, however, are quite costly with bioprinters costing thousands of dollars. This limits the access of a very promising tissue engineering technique. One solution is to modify a plastic 3D printer for bioprinting purposes. Traditional 3D printers are much cheaper and more accessible than bioprinters and can be easily modified by using a syringe pump, and tubing, to attach the hydrogel material to the extruder head. This allows hydrogel bioink solutions to be loaded into the syringe and maintains the precision of the print by keeping the syringe and needle separated by the tubing. Using this set up, gelatin methacryloyl (GelMA) and agarose solutions can be printed without affecting their mechanical or structural properties.

Materials and

Methods: The Ender-5 Pro (Creality) 3D plastic printer was purchased and assembled following the guidebook. To modify the printer for bioprinting, parts were printed in t-glass from Darling and Smith after adjustments were made in SolidWorks to fit the parts to the Ender-5 Pro printer. GelMA was made at a 22% (w/v) concentration using bovine gelatin with a 1% (w/v) concentration of IC 2959 photoinitiator. Agarose solution was made at a 1% (w/v) concentration with 1% (w/v) Calcium Chloride to ensure proper thermal curing temperature. The scaffold geometries were made in SolidWorks and uploaded into the PursaSlicer software (version 2.7.4). Print settings were also adjusted in the PursaSlicer software for ideal printing speed, layer height, and infill percentage of each material.

Results, Conclusions, and Discussions: Both GelMA and agarose bioinks have been successfully printed using the modified 3D printer. Both materials cure thermally at 37C as they print to form the scaffold. The GelMA prints were additionally photo-crosslinked under UV light for 5 minutes. Compression testing and microscopy will take place on the cured prints. It is expected that the pore diameter and porosity in these scaffolds will align with previous bioprinting studies. It is also expected that the mechanical testing reveals no difference in either material’s mechanical characteristics between printed and non-printed materials. Swelling testing will also be conducted with phosphate buffered saline (PBS), and it is assumed that the material’s swelling will not be affected by the printing process.
Creating a cheap bioprinting process that does not affect hydrogel material characteristics is a huge step. It creates an accessibility that is not currently available in traditional bioprinters. Current bioprinters can cost from $25,000 to $300,000 which severely limits access to the printers themselves and to the resultant products. Increasing accessibility of bioprinting by offering a modification to 3D plastic printers which are already commonly available and cost significantly less ($500 to $1,500) would enable more bioprinting research leading to more rapid development of unique treatments.
One example of an application for this modified bioprinting process is in the human meniscus. Current treatments for injured menisci are limited by the low vascularity which limits self-healing and the structure’s unique geometry. The printing process could replicate the half-moon architecture and triangular cross-section of the meniscus for replacements that are personalized to the individual. 3D printing could easily customize the size and geometry of a patient’s meniscus using a CT scan and converting it to a printable file. This personalized medicine reduces the need for more complex molding or donor transplants making these treatments easier and cheaper.

Acknowledgements (Optional):