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International Journal of Bioprinting Bioprinting organoids for toxicity testing

the rheology of bioink to make it more suitable for inkjet printer has unique advantages over other 3D printers, such
printing. In addition, real-time monitoring systems, such as no moving beam, small vibration deviation, no moving
as optical sensors or imaging technology, can be introduced nozzle, no material blocking, no heating parts, improved
to detect cell ejections in real time, ensuring the accuracy electrical safety, more energy saving, and reduced utilization
and controllability of the printing process. of the consumables compared with other methods. The
As the earliest form of bioprinting technology, inkjet strength, stiffness, and heat resistance of the construct
printing uses piezoelectricity or heat to drive the nozzle and after printing are limited, which is not conducive to long-
divide the bioink (a mixture of hydrogels and cells) into a series term preservation. The need to design support structure
of microdroplets, which can be printed layer by layer to form while using this technology is also another shortcoming.
a 3D structure-containing cells. Inkjet printing is relatively In addition, the introduction of real-time imaging
low-cost because inkjet 3D bioprinters can be transformed technology, such as light microscopy, allows real-time
from commercial printers. Furthermore, the inkjet printer monitoring of the printing process and timely correction
can be installed with multiple nozzles, which can print of possible deviations. In addition, considering the
different cells at the same time and at a rapid pace. Due to the sensitivity of different cell types to light and photosensitive
low driving pressure of the nozzle, it is impossible to print materials, specific printing parameters and conditions can
materials with high viscosity and high concentration of cells. be studied to optimize the living environment of cells. At
On the other hand, the structural strength of the construct the same time, combination of bioprinting with automatic
printed with low-viscosity material reduces, rendering the programming technology can help achieve the automatic
construct unable to meet the needs of subsequent in vitro control of the printing process, thereby improving the
culture and transplantation. In light of this, material viscosity consistency and reliability of printing.
is a critical factor to consider, and it narrows the range of 2.4. Automatic programmed bioprinting based on
biomaterials that can be applied for bioconstruction. The artificial intelligence
occurrence of mechanical or thermal damage to cells during Artificial intelligence-based automatic programmed
inkjet printing process also limits the wide application of bioprinting technology is an innovative frontier in the
inkjet printing technology. In addition, considering the field of contemporary biomedicine, combining AI with
pressure and force of inkjet bioprinting technology on cells, bioprinting to achieve automated programming and
it is of importance to develop highly biocompatible inkjet control. The technology automatically generates optimal
materials. At the same time, optimization of the printing printing procedures by analyzing multiple factors,
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parameters and procedures can help achieve high-density such as cell properties, biomaterial properties, and
arrangement of cells, thus increasing the physiological printing parameters, enabling efficient and precise tissue
resemblance of the construct to real tissues. construction. First, AI-based automatic programming
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2.3. Bioprinting based on digital light processing greatly simplifies the operation process, reduces
Bioprinting technology based on digital light processing human intervention, and improves the consistency and
(DLP) is an innovative 3D bioprinting method that utilizes repeatability of printing. Secondly, with the continuous
photosensitive materials and light control to achieve high- evolution of AI algorithms, the technology is expected
precision directional printing with cells and biological to be able to achieve precise control of more complex cell
materials. By focusing and controlling the light beam, the organization, thus expanding the field of application. In
technique can precisely control the distribution of cells at addition, by combining real-time monitoring and feedback
the microscopic scale, providing a new way to construct systems, real-time adjustment and optimization of the
complex biological tissues. 38-40 The first step in DLP-based printing process can be realized, further improving the
bioprinting is to optimize the formula of photosensitive precision and accuracy of printing (Figure 2B). However,
materials. The properties of photosensitive materials can this technology still faces some challenges in algorithm
be adjusted according to different cell types and application development and model training, which requires plenty of
needs, so that the right curing speed and biocompatibility data support and algorithm optimization. Since bioprinting
under light can be achieved, thus ensuring cell survival process involves knowledge of complex cell biology and
and function. The beam control system can be improved materials engineering, interdisciplinary collaboration
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to enhance the focusing and positioning accuracy of the will become the key focus in the future development of
beam to achieve higher resolution printing. this field. In summary, AI-based automatic programmed
bioprinting technology is expected to play an important
In DLP light curing 3D printing, digital light is projected role in the construction of pancreatic islets and in vitro
layer by layer on the surface of the photosensitive liquid tumor models, promoting further breakthroughs and
resin to induce layer-by-layer curing. DLP light curing 3D innovations in the field of bioprinting.

Volume 10 Issue 1 (2024) 128 https://doi.org/10.36922/ijb.1256