Page 36 - IJB-9-3

International Journal of Bioprinting Comparison of different 3D printing technologies

to its composition based on phosphate-buffered saline components of many tissue basement membranes. It is a
(PBS) and HEPES buffer, Reconstitution Agent P makes very useful substrate for 3D cell culture and in vivo studies
the bioink suitable for cell culture applications. to analyze differentiation, developmental, and pathological

Reconstitution Agents A and P were supplied by pathways, as well as for testing inhibitors/stimulators of
CELLINK [13,14] . these processes and for drug screening, toxicology testing,
or disease modeling . This material converts to solid state
[23]
2.1.4. Collagen buffer at 37°C.
Collagen buffer allows both ColMA and Coll1 to have the
right pH conditions for cell culture. 2.2. Equipment
The following equipment was used:
The usefulness of buffers, both in the regulation of
[24]
acid–base balance in living organisms and when working (i) Ender 3 Pro 3D printer , which allows the printing
in laboratories, lies in the possibility of keeping the of numerous types of filaments, such as PLA,
concentration of hydrogen ions (H ) within very narrow acrylonitrile butadiene styrene (ABS), polyethylene
+
limits. Thanks to the phenol red in their composition, they terephthalate glycol (PETG), among others.
allow the pH to be adjusted so that it is suitable both for the (ii) BIO X Bioprinter , which is equipped with three
[25]
viscosity of the bioink and for cell survival. interchangeable heads allowing the use of up to three
Collagen buffer was supplied by CELLINK . different materials or tools for tissue bioprinting.
[15]
(iii) Einscan-SE 3D scan , which allows dual scanning,
[26]
2.1.5. Sodium hydroxide (NaOH) i.e., automatic scanning and fixed scanning.
Sodium hydroxide (NaOH) in lentils was supplied by
PanReac AppliChem . Both NaOH and HCl were used to (iv) Autograph AG IS, which is a universal testing
[16]
adjust the solution to an appropriate pH . machine for compression and tensile studies.
[17]
2.1.6. GelMA Lyophilizate 2.3. Methods
GelMA Lyophilizate is a porcine gelatin-based hybrid 2.3.1. ColMa Lyophilizate reconstitution
hydrogel that provides cells with an optimal medium for The desired volume of Reconstitution Agent A was added
cell growth. The bonds of this bioink are modified with to the ColMA vial to achieve the target concentration of the
methacrylate groups to crosslink with a photoinitiator stock solution (CS). Sterile stir bar was added for mixing
when exposed to ultraviolet light, conferring enhanced gently overnight at 4°C without generating air bubbles. The
structural capacity. appropriate amount of collagen buffer and photoinitiator

GelMA Lyophilizate was supplied by CELLINK . was mixed. The mixture was filtered through 0.22-µm
[18]
syringe filters. The collagen solution was neutralized on ice
2.1.7. CELLINK Start by adding the mixture to the appropriate amount of stock
CELLINK Start is a water-soluble gel used as a support solution to obtain the desired final concentration. The pH
material for complex structures, constructions with was adjusted by adding 1M NaOH until a color indicative
porosity along all three axes, and cell-loaded constructions. of pH 6.9–7.3 and PBS was reached, and the mixture was
This gel is printed at room temperature . homogenized to obtain the neutralized ColMa hydrogel.
[19]
The contents were transferred into a syringe.
2.1.8. HAMA Lyophilizate
HAMA Lyophilizate is a hybrid hydrogel based on 2.3.2. GelMA Lyophilizate reconstitution
hyaluronic acid with methacrylate that can be cross-linked The desired amount of photoinitiator was dissolved in
in the presence of a photoinitiator. the corresponding volume of Reconstitution Agent P. The
HAMA Lyophilizate was supplied by CELLINK . solution was filtered through 0.22-µm syringe filters.
[20]
The filtered mixture was added to the vial of GelMA
2.1.9. PCL Lyophilizate, and the mixture was heated at 50°C for
Ester-terminated polycaprolactone (PCL) is a 60 min. The pH was adjusted by the use of NaOH or HCl
biodegradable, high molecular weight, linear thermoplastic to the optimum range of 7.0–7.4. The GelMA solution was
polyester with a melting point of 60°C and provides a transferred into a syringe.
reinforcing structure for tissue-loading constructs .
[21]
2.3.3. HAMA Lyophilizate
2.1.10. Matrigel The desired amount of photoinitiator was dissolved in
Matrigel is an Engelbreth–Holm–Swarm (EHS) murine the corresponding volume of Reconstitution Agent P. The
tumor-derived extract . It contains all known major solution was filtered through 0.22-µm syringe filters. The
[22]

Volume 9 Issue3 (2023) 28 https://doi.org/10.18063/ijb.680