Application of biomaterial-based three-dimensional bioprinting for organ-on-a-chip fabrication

An organ-on-a-chip is a microfluidic device that simulates the microenvironment of organs, facilitating the study of human physiology and disease mechanisms. Through the integration of tissue engineering and micromachining technologies, it effectively manages the cellular microenvironment and implements tissue-specific functions and physiological responses with high fidelity. Several factors must be appropriately considered in the fabrication of an organ-on-a-chip, including the choice of biomaterials to simulate the extracellular matrix (ECM), selection of cells constituting the target organ, incorporation of humanized design to realize the primary function and structure of the organ, and the use of appropriate biofabrication methods to build a tissue-specific environment. Notably, three-dimensional (3D) bioprinting has emerged as a promising method for biofabricating organ-on-a-chip. Threedimensional bioprinting offers versatility in adapting to various biomaterials with different physical properties, allowing precise control of 3D cell arrays and facilitating cyclic movements of fluidic flow within microfluidic platforms. These capabilities enable the precise fabrication of organ-on-a-chip that reflects tissue-specific functions and microenvironments. Additionally, 3D-bioprinted organ-on-a-chip can serve as a disease-on-a-chip platform, achieved through the implementation of pathophysiological environments and integration with devices such as bioreactors. Their significance in pharmacology research lies in their exceptional resemblance to the 3D microenvironment structure of actual organs, which are conducive for the validation of sequential mechanism of drug action. This review describes recent examples of organ-on-a-chip applications for various organs and state-of-the-art 3D bioprinting techniques employed in organ-on-a-chip fabrication. The discussion extends to the future prospects of this technology, encompassing aspects such as commercialization through mass production and its potential application in personalized medicine or drug-screening platforms. Serving as a relevant guide, this review offers insights for future research and developments in in vitro micromodel fabrication.