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International Journal of Bioprinting Bioprinted organ-on-a-chip with biomaterials

Figure 2. Schematics of 3D bioprinting methods based on the operating principle. (A) Extrusion-based bioprinting. (B) Inkjet bioprinting. (C) Laser-
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assisted bioprinting. (D) Stereolithographic bioprinting. (Reproduced with permission from Jang et al. ; (A–D) Copyright © 2016, American Chemical
Society).
and complex biological structures due to its capability for photopolymer through selective photopolymerization
high-resolution droplet printing. 84 using UV, infrared, and visible light. The laser pulse
hardens the biomaterial containing the photoinitiator in
2.2.3. Laser-assisted bioprinting the reservoir into a 2D pattern and builds up the solidified
Laser-assisted bioprinting uses pulsed laser energy to 2D pattern through a layer-by-layer process to create a
create droplets containing cells and deliver materials complex 3D biological structure. 88
(Figure 2C). A laser-assisted bioprinting system comprises
a pulsed laser beam, ribbon, and receiving substrate. 3. Application of organ-on-a-chip fabricat-
Focusing a laser pulse on the absorber metal layer of the ed using 3D bioprinting in various organ
ribbon creates a high-pressure bubble that pushes the simulations
cell-containing biomaterial onto the collector substrate.
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This printing method utilizes laser pulses at high speed; The complete replication of an actual human organ
therefore, high-density cell droplets can be printed in is deemed impossible given the current limitations of
a short time, and high-resolution structures can be technology, and the creation of organ mimetics matching
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created. Additionally, in contrast to extrusion bioprinting the size of human organs remains unattainable. This
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systems, nozzle clogging does not occur during printing. persisting hurdle stands as a central issue in the field
However, laser-assisted bioprinting systems exhibit low of 3D bioprinting. However, significant strides have
cell viability in the hydrogel compared with other inkjet been made in the fabrication of small-scale organs-on-
printing systems. 87 a-chip using 3D bioprinting technology, where primary
organ features are mimicked, resulting in favorable
Stereolithography (SLA) is one of the oldest and outcomes. 85,90-94 In particular, research endeavors have
most commonly used laser-assisted bioprinting methods focused on the skin and blood vessels, which are prevalent
(Figure 2D), suitable for creating complex 3D shapes. throughout the human body, as well as studies on kidneys
The method induces the coagulation of the liquid that exhibit a unique filtration function, playing a pivotal

Volume 10 Issue 1 (2024) 27 https://doi.org/10.36922/ijb.1972