3D Bioprinting Techniques Research Articles

Focus on seed cells: stem cells in 3D bioprinting of corneal grafts.

Corneal opacity is one of the leading causes of severe vision impairment. Corneal transplantation is the dominant therapy for irreversible corneal blindness. However, there is a worldwide shortage of donor grafts and consequently an urgent demand for alternatives. Three-dimensional (3D) bioprinting is an innovative additive manufacturing technology for high-resolution distribution of bioink to construct human tissues. The technology has shown great promise in the field of bone, cartilage and skin tissue construction. 3D bioprinting allows precise structural construction and functional cell printing, which makes it possible to print personalized full-thickness or lamellar corneal layers. Seed cells play an important role in producing corneal biological functions. And stem cells are potential seed cells for corneal tissue construction. In this review, the basic anatomy and physiology of the natural human cornea and the grafts for keratoplasties are introduced. Then, the applications of 3D bioprinting techniques and bioinks for corneal tissue construction and their interaction with seed cells are reviewed, and both the application and promising future of stem cells in corneal tissue engineering is discussed. Finally, the development trends requirements and challenges of using stem cells as seed cells in corneal graft construction are summarized, and future development directions are suggested.

Advanced biomedical and electronic dual-function skin patch created through microfluidic-regulated 3D bioprinting

Artificial skin involves multidisciplinary efforts, including materials science, biology, medicine, and tissue engineering. Recent studies have aimed at creating skins that are multifunctional, intelligent, and capable of regenerating tissue. In this work, we present a specialized 3D printing ink composed of polyurethane and bioactive glass (PU-BG) and prepare dual-function skin patch by microfluidic-regulated 3D bioprinting (MRBP) technique. The MRBP endows the skin patch with a highly controlled microstructure and superior strength. Besides, an asymmetric tri-layer is further constructed, which promotes cell attachment and growth through a dual transport mechanism based on hydrogen bonds and gradient structure from hydrophilic to superhydrophilic. More importantly, by combining the features of biomedical skin with electronic skin (e-skin), we achieved a biomedical and electronic dual-function skin patch. In vivo experiments have shown that this skin patch can enhance hemostasis, resist bacterial growth, stimulate the regeneration of blood vessels, and accelerate the healing process. Meanwhile, it also mimics the sensory functions of natural skin to realize signal detection, where the sensitivity reached up to 5.87 kPa−1, as well as cyclic stability (over 500 cycles), a wide detection range of 0–150 kPa, high pressure resolution of 0.1 % under the pressure of 100 kPa. This work offers a versatile and effective method for creating dual-function skin patches and provide new insights into wound healing and tissue repair, which have significant implications for clinical applications.

3D-bioprinted bone for regenerative medicine: Current concepts and future perspectives

The shortages in human tissue and organ donors have made clinical therapy relatively challenging. Therefore, research has been initiated over the last decades to develop artificial tissues and organs, particularly from cell and tissue cultures. Three-dimensional (3D) bioprinting is a recent technology capable of building structures for implantation, and these constructs closely resemble native tissues, such as skin, liver, connective tissues, and supportive tissues (bone and cartilage). In this review, we briefly introduce the structure, function, and development of bone tissues, followed by a detailed discussion on 3D bioprinting techniques, materials, and their recent advancements for clinical applications.

Breathing new life into tissue engineering: exploring cutting-edge vascularization strategies for skin substitutes.

Tissue-engineered skin substitutes (TESS) emerged as anew therapeutic option to improve skin transplantation. However, establishing an adequate and rapid vascularization in TESS is a critical factor for their clinical application and successful engraftment in patients. Therefore, several methods have been applied to improve the vascularization of skin substitutes including (i) modifying the structural and physicochemical properties of dermal scaffolds; (ii) activating biological scaffolds with growth factor-releasing systems or gene vectors; and (iii) developing prevascularized skin substitutes by loading scaffolds with capillary-forming cells. This review provides a detailed overview of the most recent and important developments in the vascularization strategies for skin substitutes. Onthe one hand, we present cell-based approaches using stem cells, microvascular fragments, adipose tissue derived stromal vascular fraction, endothelial cells derived from blood and skin as well as other pro-angiogenic stimulation methods. On the other hand, we discuss how distinct 3D bioprinting techniques and microfluidics, miRNA manipulation, cell sheet engineering and photosynthetic scaffolds like GelMA, can enhance skin vascularization for clinical applications. Finally, we summarize and discuss the challenges and prospects of the currently available vascularization techniques that may serve as a steppingstone to a mainstream application of skin tissue engineering.

Advancement in Cancer Vasculogenesis Modeling through 3D Bioprinting Technology.

Cancer vasculogenesis is a pivotal focus of cancer research and treatment given its critical role in tumor development, metastasis, and the formation of vasculogenic microenvironments. Traditional approaches to investigating cancer vasculogenesis face significant challenges in accurately modeling intricate microenvironments. Recent advancements in three-dimensional (3D) bioprinting technology present promising solutions to these challenges. This review provides an overview of cancer vasculogenesis and underscores the importance of precise modeling. It juxtaposes traditional techniques with 3D bioprinting technologies, elucidating the advantages of the latter in developing cancer vasculogenesis models. Furthermore, it explores applications in pathological investigations, preclinical medication screening for personalized treatment and cancer diagnostics, and envisages future prospects for 3D bioprinted cancer vasculogenesis models. Despite notable advancements, current 3D bioprinting techniques for cancer vasculogenesis modeling have several limitations. Nonetheless, by overcoming these challenges and with technological advances, 3D bioprinting exhibits immense potential for revolutionizing the understanding of cancer vasculogenesis and augmenting treatment modalities.

3D Bioprinting of Biomimetic Alginate/Gelatin/Chondroitin Sulfate Hydrogel Nanocomposites for Intrinsically Chondrogenic Differentiation of Human Mesenchymal Stem Cells.

3D-printed hydrogel scaffolds biomimicking the extracellular matrix (ECM) are key in cartilage tissue engineering as they can enhance the chondrogenic differentiation of mesenchymal stem cells (MSCs) through the presence of active nanoparticles such as graphene oxide (GO). Here, biomimetic hydrogels were developed by cross-linking alginate, gelatin, and chondroitin sulfate biopolymers in the presence of GO as a bioactive filler, with excellent processability for developing bioactive 3D printed scaffolds and for the bioprinting process. A novel bioink based on our hydrogel with embedded human MSCs presented a cell survival rate near 100% after the 3D bioprinting process. The effects of processing and filler concentration on cell differentiation were further quantitatively evaluated. The nanocomposited hydrogels render high MSC proliferation and viability, exhibiting intrinsic chondroinductive capacity without any exogenous factor when used to print scaffolds or bioprint constructs. The bioactivity depended on the GO concentration, with the best performance at 0.1 mg mL-1. These results were explained by the rational combination of the three biopolymers, with GO nanoparticles having carboxylate and sulfate groups in their structures, therefore, biomimicking the highly negatively charged ECM of cartilage. The bioactivity of this biomaterial and its good processability for 3D printing scaffolds and 3D bioprinting techniques open up a new approach to developing novel biomimetic materials for cartilage repair.

Advancing Engineered Plant Living Materials through Tobacco BY-2 Cell Growth and Transfection within Tailored Granular Hydrogel Scaffolds.

In this study, an innovative approach is presented in the field of engineered plant living materials (EPLMs), leveraging a sophisticated interplay between synthetic biology and engineering. We detail a 3D bioprinting technique for the precise spatial patterning and genetic transformation of the tobacco BY-2 cell line within custom-engineered granular hydrogel scaffolds. Our methodology involves the integration of biocompatible hydrogel microparticles (HMPs) primed for 3D bioprinting with Agrobacterium tumefaciens capable of plant cell transfection, serving as the backbone for the simultaneous growth and transformation of tobacco BY-2 cells. This system facilitates the concurrent growth and genetic modification of tobacco BY-2 cells within our specially designed scaffolds. These scaffolds enable the cells to develop into predefined patterns while remaining conducive to the uptake of exogenous DNA. We showcase the versatility of this technology by fabricating EPLMs with unique structural and functional properties, exemplified by EPLMs exhibiting distinct pigmentation patterns. These patterns are achieved through the integration of the betalain biosynthetic pathway into tobacco BY-2 cells. Overall, our study represents a groundbreaking shift in the convergence of materials science and plant synthetic biology, offering promising avenues for the evolution of sustainable, adaptive, and responsive living material systems.

Association of Electrospinning and 3D Bioprinting techniques for fabrication of cellularized vascular grafts: a proof of concept

Association of Electrospinning and 3D Bioprinting techniques for fabrication of cellularized vascular grafts: a proof of concept

Applications of 3D Bioprinting Technology to Brain Cells and Brain Tumor Models: Special Emphasis to Glioblastoma.

Primary brain tumor is one of the most fatal diseases. The most malignant type among them, glioblastoma (GBM), has low survival rates. Standard treatments reduce the life quality of patients due to serious side effects. Tumor aggressiveness and the unique structure of the brain render the removal of tumors and the development of new therapies challenging. To elucidate the characteristics of brain tumors and examine their response to drugs, realistic systems that mimic the tumor environment and cellular crosstalk are desperately needed. In the past decade, 3D GBM models have been presented as excellent platforms as they allowed the investigation of the phenotypes of GBM and testing innovative therapeutic strategies. In that scope, 3D bioprinting technology offers utilities such as fabricating realistic 3D bioprinted structures in a layer-by-layer manner and precisely controlled deposition of materials and cells, and they can be integrated with other technologies like the microfluidics approach. This Review covers studies that investigated 3D bioprinted brain tumor models, especially GBM using 3D bioprinting techniques and essential parameters that affect the result and quality of the study like frequently used cells, the type and physical characteristics of hydrogel, bioprinting conditions, cross-linking methods, and characterization techniques.

Construction Form and Application of Three-Dimensional Bioprinting Ink Containing Hydroxyapatite.

With the increasing prevalence of bone tissue diseases, three-dimensional (3D) bioprinting applied to bone tissue engineering for treatment has received a lot of interests in recent years. The research and popularization of 3D bioprinting in bone tissue engineering require bioinks with good performance, which is closely related to ideal material and appropriate construction form. Hydroxyapatite (HAp) is the inorganic component of natural bone and has been widely used in bone tissue engineering and other fields due to its good biological and physicochemical properties. Previous studies have prepared different bioinks containing HAp and evaluated their properties in various aspects. Most bioinks showed significant improvement in terms of rheology and biocompatibility; however, not all of them had sufficiently favorable mechanical properties and antimicrobial activity. The deficiencies in properties of bioink and 3D bioprinting technology limited the applications of bioinks containing HAp in clinical trials. This review article summarizes the construction forms of bioinks containing HAp and its modifications in previous studies, as well as the 3D bioprinting techniques adopted to print bioink containing HAp. In addition, this article summarizes the advantages and underlying mechanisms of bioink containing HAp, as well as its limitations, and suggests possible improvement to facilitate the development of bone tissue engineering bioinks containing HAp in the future.

The development of a modular and open-source multi-head 3D bioprinter for fabricating complex structures

Various 3D bioprinting techniques have been introduced and developed to fabricate biomimetic constructs based on biomaterials or cell-laden bioinks to create functionally engineered tissues or organs for tissue engineering applications. However, single-biomaterial printing techniques often fail to replicate the intricate compositions and diversity found in native tissues. Multi-bioinks or multi-biomaterials in bioprinting can be utilized through either a single printhead or multiple separate printheads. However, the cost of commercially available multi-heads for bioprinting is prohibitively high, hindering their application in tissue engineering endeavors. Additionally, each bioink or biomaterial possesses unique printing characteristics that are best suited for specific printing techniques. The current study presents the development of a modular and cost-effective dual-head position bioprinter based on an open-source approach using Marlin firmware. The highlighted features of the 3D bioprinter include the use of various power sources such as compressed air and electricity for the printheads, the integration of a movable printhead mechanism with a wiper arm to prevent collisions with large printed samples during printing, a printhead adapter, as well as nozzle kits designed in a modular form for easy replacement for specific bio-applications. Therefore, despite the presence of two positions to mount the printheads, the custom-designed bioprinter exhibits the capability to flexibly accommodate four distinct printhead modules and three modular nozzle kits to print various biomaterials, such as polycaprolactone (PCL) and its composites with sodium alginate (SA), tricalcium phosphate (TCP) and hydrogel mixtures including SA, gelatin (GL), and k-carrageenan (κ-Carr). Complex tissue scaffolds were successfully fabricated using multi-biomaterials to showcase the versatility of the bioprinter, thereby demonstrating its potential for a wide range of tissue engineering applications.

Application of Bioactive Materials for Osteogenic Function in Bone Tissue Engineering.

Bone tissue defects present a major challenge in orthopedic surgery. Bone tissue engineering using multiple versatile bioactive materials is a potential strategy for bone-defect repair and regeneration. Due to their unique physicochemical and mechanical properties, biofunctional materials can enhance cellular adhesion, proliferation, and osteogenic differentiation, thereby supporting and stimulating the formation of new bone tissue. 3D bioprinting and physical stimuli-responsive strategies have been employed in various studies on bone regeneration for the fabrication of desired multifunctional biomaterials with integrated bone tissue repair and regeneration properties. In this review, biomaterials applied to bone tissue engineering, emerging 3D bioprinting techniques, and physical stimuli-responsive strategies for the rational manufacturing of novel biomaterials with bone therapeutic and regenerative functions are summarized. Furthermore, the impact of biomaterials on the osteogenic differentiation of stem cells and the potential pathways associated with biomaterial-induced osteogenesis are discussed.

3D Bioprinting and Microfluidic-Based Devices for Cancer Detection and Drug Treatment: Focus on Prostate Cancer.

The burden of increasing cancer incidence among the population, and, in particular, of prostate cancer in men living in highly developed countries, brings with it, on one hand, the need for new devices that allow a faster and earlier diagnosis, ideally in a non-invasive way and with low consumption of expensive reagents, and on the other the need for the assessment of new in vitro models that allow a more reliable assessment of cancer features, including its microenvironment and sensibility to different drugs. At the crossroads of these features, microfluidic devices are found. These, taking advantage of the chemical-physical properties of cells and human samples, have demonstrated great sensitivity and sensibility at an on-chip scale. Many fields of biomedical sciences have tried to exploit all their potentialities: from the detection of antigens in the early phases of the disease (when they are very low concentrated, but the treatment is more effective) to isolation and characterization of circulating tumor cells. However, the development of in vitro 3D models to better assess and comprehend the fundamental dynamics of tumor microenvironment and metastasis using 3D bioprinting techniques. The aim of the present review is to describe the potential of these two different cutting-edge technologies for the detection and treatment of prostate cancer, in the perspective of a possible future combination of them that allows scientists to fill the gaps present in the field to improve patient care and treatment.

Clay Sculpture-Inspired 3D Printed Microcage Module Using Bioadhesion Assembly for Specific-Shaped Tissue Vascularization and Regeneration.

3D bioprinting techniques have enabled the fabrication of irregular large-sized tissue engineering scaffolds. However, complicated customized designs increase the medical burden. Meanwhile, the integrated printing process hinders the cellular uniform distribution and local angiogenesis. A novel approach is introduced to the construction of sizable tissue engineering grafts by employing hydrogel 3D printing for modular bioadhesion assembly, and a poly (ethylene glycol) diacrylate (PEGDA)-gelatin-dopamine (PGD) hydrogel, photosensitive and adhesive, enabling fine microcage module fabrication via DLP 3D printing is developed. The PGD hydrogel printed micocages are flexible, allowing various shapes and cell/tissue fillings for repairing diverse irregular tissue defects. In vivo experiments demonstrate robust vascularization and superior graft survival in nude mice. This assembly strategy based on scalable 3D printed hydrogel microcage module could simplify the construction of tissue with large volume and complex components, offering promise for diverse large tissue defect repairs.

Fabrication Method for Shape-Controlled 3D Tissue Using High-Porosity Porous Structure.

Shape-controlled 3D tissues resemble natural living tissues in human and animal bodies and are essential materials for developing and improving technologies in regenerative medicine, drug discovery, and biological robotics. In previous studies, shape-controlled 3D tissues were fabricated using scaffold structures or 3D bioprinting techniques. However, controlling the shape of 3D tissues without leaving non-natural materials inside the 3D tissue and efficiently fabricating them remains challenging. In this paper, we propose a novel method for fabricating shape-controlled 3D tissues free of non-natural materials using a flexible high-porosity porous structure (HPPS). The HPPS consisted of a micromesh with pore sizes of 14.87 ± 1.83 μm, lattice widths of 2.24 ± 0.10 μm, thicknesses of 9.96 ± 0.92 μm, porosity of 69.06 ± 3.30%, and an I-shaped microchamber of depth 555.26 ± 11.17 μm. U-87 human glioma cells were cultured in an I-shaped HPPS microchamber for 48 h. After cultivation, the 3D tissue was released within a few seconds while maintaining its I-shape. Specific chemicals, such as proteolytic enzymes, were not used. Moreover, the viability of the released cells composed of shape-controlled 3D tissues free of non-natural materials was above 90%. Therefore, the proposed fabrication method is recommended for shape-controlled 3D tissues free of non-natural materials without applying significant stresses to the cells.

Multilayered Shape-Morphing Scaffolds with a Hierarchical Structure for Uterine Tissue Regeneration.

Owing to dysfunction of the uterus, millions of couples around the world suffer from infertility. Different from conventional treatments, tissue engineering provides a new and promising approach to deal with difficult problems such as human tissue or organ failure. Adopting scaffold-based tissue engineering, three-dimensional (3D) porous scaffolds in combination with stem cells and appropriate biomolecules may be constructed for uterine tissue regeneration. In this study, a hierarchical tissue engineering scaffold, which mimicked the uterine tissue structure and functions, was designed, and the biomimicking scaffolds were then successfully fabricated using solvent casting, layer-by-layer assembly, and 3D bioprinting techniques. For the multilayered, hierarchical structured scaffolds, poly(l-lactide-co-trimethylene carbonate) (PLLA-co-TMC, "PLATMC" in short) and poly(lactic acid-co-glycolic acid) (PLGA) blends were first used to fabricate the shape-morphing layer of the scaffolds, which was to mimic the function of myometrium in uterine tissue. The PLATMC/PLGA polymer blend scaffolds were highly stretchable. Subsequently, after etching of the PLATMC/PLGA surface and employing estradiol (E2), polydopamine (PDA), and hyaluronic acid (HA), PDA@E2/HA multilayer films were formed on PLATMC/PLGA scaffolds to build an intelligent delivery platform to enable controlled and sustained release of E2. The PDA@E2/HA multilayer films also improved the biological performance of the scaffold. Finally, a layer of bone marrow-derived mesenchymal stem cell (BMSC)-laden hydrogel [which was a blend of gelatin methacryloyl (GelMA) and gelatin (Gel)] was 3D printed on the PDA@E2/HA multilayer films of the scaffold, thereby completing the construction of the hierarchical scaffold. BMSCs in the GelMA/Gel hydrogel layer exhibited excellent cell viability and could spread and be released eventually upon biodegradation of the GelMA/Gel hydrogel. It was shown that the hierarchically structured scaffolds could evolve from the initial flat shape into the tubular structure completely in an aqueous environment at 37 °C, fulfilling the requirement for curved scaffolds for uterine tissue engineering. The biomimicking scaffolds with a hierarchical structure and curved shape, high stretchability, and controlled and sustained E2 release appear to be very promising for uterine tissue regeneration.

In‐Foam Bioprinting: An Embedded Bioprinting Technique with Self‐Removable Support Bath

The emergence of embedded three‐dimensional (3D) bioprinting has revolutionized the biofabrication of free‐form constructs out of low‐viscosity and slow‐crosslinking hydrogels. Using gel‐based support baths has limitations including lack of proper oxygenation and nutrition and complications with bath removal. Herein, a novel‐embedded 3D bioprinting technique is developed with an albumin foam support bath as a promising substitute. The proposed technique, in‐foam bioprinting, offers excellent printability and convenience in bath removal while providing cells with easy access to oxygen and nutrients. The foam‐based support bath is characterized through foam stability and rheological tests. The bubble size in the foam is measured to study the change in the structure of the bath due to the coalescence of the bubbles over time. Free‐form structures are successfully 3D printed with thermoresponsive chitosan‐based bioinks to demonstrate the capability of the in‐foam bioprinting technique. The viability of bioprinted fibroblast L929 cells is studied over a seven‐day period, showing high cell viability of over 97%, which is attributed to the abundance of oxygen and nutrition in the foam support bath. Importantly, in‐foam bioprinting is beneficial for biofabricating large samples with a long printing time without jeopardizing cell viability.

Three-Dimensional Bioprinting in Vascular Tissue Engineering and Tissue Vascularization of Cardiovascular Diseases.

In the 21st century, significant progress has been made in repairing damaged materials through material engineering. However, the creation of large-scale artificial materials still faces a major challenge in achieving proper vascularization. To address this issue, researchers have turned to biomaterials and three-dimensional (3D) bioprinting techniques, which allow for the combination of multiple biomaterials with improved mechanical and biological properties that mimic natural materials. Hydrogels, known for their ability to support living cells and biological components, have played a crucial role in this research. Among the recent developments, 3D bioprinting has emerged as a promising tool for constructing hybrid scaffolds. However, there are several challenges in the field of bioprinting, including the need for nanoscale biomimicry, the formulation of hydrogel blends, and the ongoing complexity of vascularizing biomaterials, which requires further research. On a positive note, 3D bioprinting offers a solution to the vascularization problem due to its precise spatial control, scalability, and reproducibility compared with traditional fabrication methods. This paper aims at examining the recent advancements in 3D bioprinting technology for creating blood vessels, vasculature, and vascularized materials. It provides a comprehensive overview of the progress made and discusses the limitations and challenges faced in current 3D bioprinting of vascularized tissues. In addition, the paper highlights the future research directions focusing on the development of 3D bioprinting techniques and bioinks for creating functional materials.

COMBINING MAGNETICALLY ASSISTED AND MATRIX-ASSISTED 3D BIOPRINTING FOR ANISOTROPIC TISSUE ENGINEERING

A major obstacle in biofabrication is replicating the organization of the extracellular matrix and cellular patterns found in anisotropic tissues within bioengineered constructs. While magnetically-assisted 3D bioprinting techniques have the potential to create scaffolds that mimic natural biological structures, they currently lack the ability to accurately control the dispersion of magnetic substances within the bioinks without compromising the fidelity of the intended composite. To overcome this dichotomy, the concepts of magnetically- and matrix-assisted 3D bioprinting are combined here. This method preserves the resolution of printed structures by keeping low viscosity bioinks uncrosslinked during printing, which allows for the arrangement of magnetically-responsive microfibers without compromising the structural integrity of the design. Solidification is induced after the microfibers are arranged in the desired pattern. Furthermore, the precise design of these magnetic microfillers permits the utilization of low levels of inorganic materials and weak magnetic field strengths, which reduces the potential risks that may be associated with their use. The effectiveness of this approach is evaluated in the context of tendon tissue engineering, and the results demonstrate that combining the tendons like anisotropic fibrous microstructure with remote magneto-mechanical stimulation during in vitro maturation provides both biochemical and biophysical cues that effectively guide human adipose-derived stem cells towards a tenogenic phenotype In summary, the developed strategy allows the fabrication of anisotropic high-resolution magnetic composites with remote stimulation functionalities, opening new horizons for tissue engineering applications.Acknowledgments: ERC Grant CoG MagTendon nr 772817, BioChips PoC project nr 10106930, (PD/BD/129403/2017), (CEECIND/01375/2017), (2020.03410.CEECIND), (2022.05526.PTDC), (ED481B2019/025).

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. Three-dimensional 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.