Page 71 - IJB-7-4

Avila-Ramírez, et al.
A B

C

Figure 1. Explanation from the project’s scope. (A) Integration of biopolymers gelatin, alginate, gelatin methacrylate, poly (ethylene
glycol diacrylate), and bioceramics calcium carbonate and hydroxyapatite for potential rigid-living systems. (B) Schematics from the two
primary sources of crosslinking to enhance printability, ionic-crosslinking with cations such as calcium and photo-crosslinking with a
wavelength range from 365 nm to 405 nm. (C) The proposal for a potential future application with this material for rigid-living systems can
be manufactured with extrusion-based 3D printing technologies.

Table 1. Formulation from the complete ink.
Biopolymer base Percentage W/W Weight by Purpose
cartridge sample
High gelatin methacrylate 2.50% 0.25 g. Photo-crosslinking and printability
(H-GelMA)
Poly (ethylene glycol diacrylate) 2.50% 0.25 g. ≈ 0.25 mL Increase speed rate of photo-crosslinking
(PEGDA) 700 MW
Alginic acid (Alg) Low MW 2.50% 0.25 g Ionic-crosslinking with calcium
Gelatin (Gel) 2.50% 0.25 g Viscosity for pre-crosslinked paste
Lithium phenyl-2,4,6 0.15% 0.015g Photoinitiation 365(UV) – 405 (blue) nm
trimethylbenzoylphosphinate (LAP)
Bioceramics Percentage W/W Weight in 10 mL. Purpose
Hydroxyapatite (HA) 40% 4 g Density for under wet conditions
Calcium carbonate (CaCO3) 40% 4 g Mimic coral chemical Structure
Solvent Quantity Quantity Purpose
Milli-Q water 10 mL 10 mL Dissolve

2.3. Bioceramics reinforcement printing fidelity, relying on inexpensive materials for
commercial 3D manufacturing technologies.
The quantity of bioceramics needed for the formulation
is presented in Table 1, imbued at the biopolymer- 2.4. Manufacturing
based solution prepared previously. Solid and
constant stirring with a thin spatula is crucial as the Two methodologies were used for 3D manufacturing. The
final homogenous product will be viscous, similar first one was molding of a flexible resin; it is designed in
to a commercial bone paste. It is recommended to different designs derived from real branched and brain
start 3D printing protocols with the fresh material to corals obtained in the red sea. The second one is 3D
avoid premature crosslinking with the light or natural printing based on the implementation of two systems:
desiccation of water. The formulation is intended to be A pressure-based bioprinter Inkredible from the Cellink
cost-effective because the biopolymer part from the company and the designed 6-°-of-freedom robotic arm
formulation was designed at minimal concentrations system developed for bioprinting applications at our
without compromising its crosslinking properties and research group .
[13]
International Journal of Bioprinting (2021)–Volume 7, Issue 4 67