Page 535 - IJB-9-5

International Journal of Bioprinting GelMA/PEG-TA IPN networks for 3D bioprinting

Scheme 1. Schematic 3D bioprinting procedure. Step 1: Pre-mix gel precursor and cells at 37°C. Step 2: Load to the syringe at 37°C and cool to room
temperature. Step 3: The print head and the base plate are set at 22°C during the printing of a preprogrammed construct. Step 4: Every two layers the
hydrogel is irradiated for 5 s by UV light (365 nm). Step 5: For the IPN preparation, the printed hydrogel was submerged in a 0.03 wt% H O solution for
2
2
1 min after finishing printing. Step 6: Cell culturing of the hydrogel up to 21 days.
A B

Scheme 2. Synthesis of (A) GelMA and (B) 8PEGTA .
5
by HRP in the presence of hydrogen peroxide, two control Consecutively, physically crosslinked hydrogels, photo-
experiments were performed. A solution of 8PEGTA5 crosslinked hydrogels, and IPNs, as schematically depicted
containing LAP did not form a gel on UV irradiation in Scheme 3, were formed.
(experimental details are presented in Supplementary File,
Table S1). Second, the potential crosslinking of acrylate 3.3. Solution properties and printability
groups of GelMA in the presence of HRP was verified. The favorable use of GelMA-based solutions for 3D
The experiments revealed that no gelation occurred bioprinting applications is due to the exploitation of its
when a solution of H O (at a final concentration of 0.03 temperature-dependent physical gelation properties.
2
2
wt%) was added to a 6 wt% solution of GelMa containing GelMA is well soluble in aqueous solutions at higher
4 U/mL HRP, which is in accordance with results of temperatures, allowing these pre-gelation solutions to
Danielson et al. who showed that a mediator like acetyl form stable 3D structures on cooling. An important
acetone is necessary to induce crosslinking of acrylates . parameter in the printability of GelMA-based bioinks
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Volume 9 Issue 5 (2023) 527 https://doi.org/10.18063/ijb.750