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International Journal of Bioprinting dECM bioink for in vitro disease modeling

complex structure of the liver and its cell configurations is suitable for positioning multiple cells and fabricating
in vitro. Several microfabrication techniques, such as complex liver structures on one platform, which is able
photolithography and etching, have been used to replicate to simulate cell–cell interactions. Thus, 3D-bioprinted
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the complex physiological structure of the liver and to models can reproduce the complex 3D structure and
control its function. 177,178 An in vitro model integrated with microenvironment of liver tissue, more closely reflecting
a multilayered structure composed of various liver cells has actual liver pathophysiology and increasing the reliability
been reported, and a more advanced in vitro liver model and utility of research results. These models can also
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containing sinusoidal structure that allows fluid flow has contribute to a better understanding of the mechanisms
also been developed. 180 behind the development and progression of liver disease
However, the existing models cannot recapitulate the and the development of treatment and prevention
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interactions between blood vessels and immune cells in the strategies. The significance of the in vitro liver models
liver, rendering simulation of complex metabolic pathways created by 3D bioprinting using LdECM bioink is detailed
and modeling of various liver diseases difficult. Additionally, in the following.
co-culturing various liver cells on a single platform Kang et al. prepared an LdECM-based hybrid bioink by
and reproducing a liver-specific microenvironment mixing various hydrogels, including gelatin and alginate,
is challenging. Therefore, to create a liver-specific with LdECM. Human hepatocarcinoma cells (HepG2)
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microenvironment, liver-derived dECM (LdECM) has were mixed with this hybrid bioink, and the mixture was
recently been used as a bioink for 3D bioprinting. Unlike then used in extrusion-based bioprinting to fabricate liver
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conventional manufacturing methods, 3D bioprinting tissue in hexagonal pattern (Figure 4A). The hybrid
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Figure 4. Examples of in vitro liver and respiratory models and their applications. (A, B) Fabrication of in vitro liver model using extrusion-based 3D
bioprinting with (A) LdECM-based hybrid bioink and (B) LdECM bioink, and simulation of fibrosis in this model. (C, D) Fabrication of airway-on-a-chip
and in vitro tracheal model using extrusion-based 3D bioprinting with mucosa-derived dECM: (C) fabrication of airway-on-a-chip and its application
as an asthma model, and (D) fabrication of in vitro tracheal model and its application as an inflammatory respiratory disease model. (Reproduced with
permission from 184,186,215,216 )

Volume 10 Issue 2 (2024) 147 doi: 10.36922/ijb.1970