Extrusion-based Bioprinting Research Articles

Visible light photocrosslinking of sugar beet pectin for 3D bioprinting applications

Herein, we report the hydrogelation of sugar beet pectin (SBP) via visible light-mediated photocrosslinking and its applications in extrusion-based 3D bioprinting. Rapid hydrogelation (<15 s) was achieved by applying 405 nm visible light to an SBP solution in the presence of tris(bipyridine)ruthenium(II) chloride hexahydrate ([Ru(bpy)3]2+) and sodium persulfate (SPS). The mechanical properties of the hydrogel could be tuned by controlling the visible light irradiation time and concentrations of SBP, [Ru(bpy)3]2+, and SPS. High-fidelity 3D hydrogel constructs were fabricated by extruding inks containing 3.0 wt% SBP, 1.0 mM [Ru(bpy)3]2+, and 1.0 mM SPS. Human hepatoblastoma (HepG2) cells encapsulated in SBP hydrogels remained viable and metabolically active after 14 d of culture. Overall, this study demonstrates the feasibility of applying SBP and a visible light-mediated photocrosslinking system to the 3D bioprinting of cell-laden constructs for tissue engineering applications.

Gravity-assisted 3D bioprinting: Using gravity as a design input to build high aspect-ratio structures

Extrusion-based bioprinting (EBB) offers unique advantages for 3D printing of hydrogels including superior structural integrity, high cell density, and continuous deposition. Despite these advantages, the lack of mechanical stability of printed constructs limits the fabrication of high aspect ratio constructs using EBB. Due to this limitation, patterning macroscopic scaffolds to mimic anatomical structures of a high aspect ratio remains a challenge. For example, it is difficult for EBB to print hollow tubes of an appreciable length-to-width ratio without using complicated sacrificial materials in a multi-print process. By using gravity as a 5th-dimensional input (X, Y, Z, time, gravity), we were able to generate high aspect ratio structures without further complication of 3D printer mechanics. Using gravity-assisted bioprinting methods we routinely achieved aspect ratios greater than two times those of similar constructs printed without gravity assistance.

Extrusion-Based 3D Bioprinting of Adhesive Tissue Engineering Scaffolds Using Hybrid Functionalized Hydrogel Bioinks.

Adhesive tissue engineering scaffolds (ATESs) have emerged as an innovative alternative means, replacing sutures and bioglues, to secure the implants onto target tissues. Relying on their intrinsic tissue adhesion characteristics, ATES systems enable minimally invasive delivery of various scaffolds. This study investigates development of the first class of 3D bioprinted ATES constructs using functionalized hydrogel bioinks. Two ATES delivery strategies, in situ printing onto the adherend versusprinting and then transferring to the target surface, aretested using two bioprinting methods, embedded versus air printing. Dopamine-modified methacrylated hyaluronic acid (HAMA-Dopa) and gelatin methacrylate (GelMA) are used as the main bioink components, enabling fabrication of scaffolds with enhanced adhesion and crosslinking properties. Results demonstrate that dopamine modification improved adhesive properties of the HAMA-Dopa/GelMA constructs under various loading conditions, while maintaining their structural fidelity, stability, mechanical properties, and biocompatibility. While directly printing onto the adherend yields superior adhesive strength, embedded printing followed by transfer to the target tissue demonstrates greater potential for translational applications. Together, these results demonstrate the potential of bioprinted ATESs as off-the-shelf medical devices for diverse biomedical applications.

Fitness of Custom 3D-Printed Hydroxyapatite Scaffolds for Furcation Defects: A Preliminary Investigation Using Pig Jaws

&lt;p&gt;Abstract (Word Count: 202) Objective: This study aimed to evaluate whether 3D-printed (3DP) hydroxyapatite (HA)-based scaffolds can be customized to fit furcation defects. Materials and Methods: Two experimental degree II furcation defects were created in pig jaws, and cone-beam computed tomography (CBCT) images were taken before and after defect creation. Computer-aided design (CAD) models of scaffolds were produced by subtracting two CBCT images. For each defect, one 3DP resin block printed using a stereolithographic 3D printer served as the control, and three 3DP HA-based scaffolds were printed using an extrusion-based 3DP bioprinter. The resultant 3DP resin blocks and HA-based scaffolds were placed in the defects, and micro-CT images were taken to assess the fitness of the scaffolds. Results: Compared with the CAD models, the 3DP resin blocks and HA-based scaffolds showed approximately 90% and &gt; 80% volume stability, respectively. Regarding the furcation defects, the linear adaptation ratio was approximately 90% for the 3DP resin blocks and &gt; 70% for the 3DP HA-based scaffolds. The fitness of the 3DP HA-based scaffolds was inferior, with a notable depression in the central area. Conclusion: The 3DP HA-based scaffolds exhibited acceptable volume stability and fitness for the furcation defect and could be a potential strategy for promoting furcation defect regeneration.&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;

Progress in bioprinting technology for tissue regeneration.

In recent years, due to the increase in diseases that require organ/tissue transplantation and the limited donor, on the other hand, patients have lost hope of recovery and organ transplantation. Regenerative medicine is one of the new sciences that promises a bright future for these patients by providing solutions to repair, improve function, and replace tissue. One of the technologies used in regenerative medicine is three-dimensional (3D) bioprinters. Bioprinting is a new strategy that is the basis for starting a global revolution in the field of medical sciences and has attracted much attention. 3D bioprinters use a combination of advanced biology and cell science, computer science, and materials science to create complex bio-hybrid structures for various applications. The capacity to use this technology can be demonstrated in regenerative medicine to make various connective tissues, such as skin, cartilage, and bone. One of the essential parts of a 3D bioprinter is the bio-ink. Bio-ink is a combination of biologically active molecules, cells, and biomaterials that make the printed product. In this review, we examine the main bioprinting strategies, such as inkjet printing, laser, and extrusion-based bioprinting, as well as some of their applications.

Analytics in Extrusion-Based Bioprinting: Standardized Methods Improving Quantification and Comparability of the Performance of Bioinks.

Three-dimensional bioprinting and especially extrusion-based printing as a most frequently employed method in this field is constantly evolving as a discipline in regenerative medicine and tissue engineering. However, the lack of relevant standardized analytics does not yet allow an easy comparison and transfer of knowledge between laboratories regarding newly developed bioinks and printing processes. This work revolves around the establishment of a standardized method, which enables the comparability of printed structures by controlling for the extrusion rate based on the specific flow behavior of each bioink. Furthermore, printing performance was evaluated by image-processing tools to verify the printing accuracy for lines, circles, and angles. In addition, and complementary to the accuracy metrics, a dead/live staining of embedded cells was performed to investigate the effect of the process on cell viability. Two bioinks, based on alginate and gelatin methacryloyl, which differed in 1% (w/v) alginate content, were tested for printing performance. The automated image processing tool reduced the analytical time while increasing reproducibility and objectivity during the identification of printed objects. During evaluation of the processing effect of the mixing of cell viability, NIH 3T3 fibroblasts were stained and analyzed after the mixing procedure and after the extrusion process using a flow cytometer, which evaluated a high number of cells. It could be observed that the small increase in alginate content made little difference in the printing accuracy but had a considerable strong effect on cell viability after both processing steps.

Study on composite hydrogel mixture of calcium alginate/gelatin/kappa carrageenan for 3D bioprinting

Regenerative medicine and tissue engineering are continuously advancing and utilizing new technologies to provide reliable solutions for replacing damaged tissues. Unlike subtractive manufacturing, additive manufacturing became an answer for creating complex shapes for many fields, such as tissue engineering, which requires the need to create body parts that are not geometrically simple. Three-dimensional (3D) bioprinting technology is a great additive manufacturing tool that will significantly benefit the field of regenerative medicine and tissue engineering once precision and feasibility are achieved. Printing a 3D structure narrows the range of material choices to meet the biomaterials criteria, including biocompatibility, biodegradability, printability, and low cytotoxicity. Hydrogels meet all requirements for biomaterials; however, they have weak mechanical properties that are hard to control, making it challenging to print a scaffold precisely, restricting their chance of being used as a potential reliable 3D bioprinting material. In this paper, composite scaffolds composed of calcium alginate/gelatin/κ-carrageenan are printed using an extrusion-based 3D bioprinter. Different concentrations of all three hydrogels are prepared and crosslinked with calcium chloride to transform it from sodium alginate/gelatin/κ-carrageenan to calcium alginate/gelatin/κ-carrageenan, then tested for their strength in tension. Printability is also tested for different concentrations to find the best printing parameters in terms of pressure, print speed, layer height, and printing temperature. The composite hydrogel mixture composed of 2.2% (w/v) calcium alginate/1% (w/v) gelatin/4% (w/v) κ-carrageenan exhibited a higher modulus of elasticity compared to the other tested concentrations and is printable using a 0.864 mm nozzle diameter, 62 °C printing temperature, and 48.2 kPa printing pressure.

Algorithmic linearization improves Syringe-based extrusion in elastic systems using Hydrogel-based materials

Accuracy and precision are essential in extrusion-based material handling such as three-dimensional (3D) bioprinting. However, the elasticity of components, backlash, variability of nozzle and cartridge shapes, etc. can lead to unpredictable printing results, which is further complicated by the wide range of rheologically diverse materials and complex sample designs.To address this issue, we present an algorithmic approach to compensate for the discrepancies between piston motion and material extrusion in syringe-based extrusion systems. This approach relies on cyclical, iterative optimization through rapid piston movements, which are adjusted based on extrusion analysis.In this work we establish a general theoretical framework for extrusion and link the rheological properties of prepared hydrogels with shear rates in a typical bioprinting process. The determined properties are compared with the success of the developed algorithm to modify machine instructions for precise material deposition of short, interrupted lines, as well as multi-layered scaffold structures.Overall, our approach provides a means of improving the accuracy and precision of complex extrusion-based bioprinting systems, without prior knowledge of set-up or material properties, making it highly versatile and suitable for a wide range of applications, particularly when the combined set-up and material properties are too complex for solely predictive approaches.

Perfusable Biohybrid Designs for Bioprinted Skeletal Muscle Tissue.

Engineered, centimeter-scale skeletal muscle tissue (SMT) can mimic muscle pathophysiology to study development, disease, regeneration, drug response, and motion. Macroscale SMT requires perfusable channels to guarantee cell survival, and support elements to enable mechanical cell stimulation and uniaxial myofiber formation. Here, stable biohybrid designs of centimeter-scale SMT are realized via extrusion-based bioprinting of an optimized polymeric blend based on gelatin methacryloyl and sodium alginate, which can be accurately coprinted with other inks. A perfusable microchannel network is designed to functionally integrate with perfusable anchors for insertion into a maturation culture template. The results demonstrate that i) coprinted synthetic structures display highly coherent interfaces with the living tissue, ii) perfusable designs preserve cells from hypoxia all over the scaffold volume, iii) constructs can undergo passive mechanical tension during matrix remodeling, and iv) the constructs can be used to study the distribution of drugs. Extrusion-based multimaterial bioprinting with the inks and design realizes in vitro matured biohybrid SMT for biomedical applications.

3D-Printed disposable nozzles for cost-efficient extrusion-based 3D bioprinting

3D bioprinting has significantly impacted tissue engineering with its capability to create intricate structures with complex geometries that were difficult to replicate through traditional manufacturing techniques. Extrusion-based 3D bioprinting methods tend to be limited when creating complex structures using bioinks of low viscosity. However, the capacity for creating multi-material structures that have distinct properties could be unlocked through the mixture of two solutions before extrusion. This could be used to generate architectures with varying levels of stiffness and hydrophobicity, which could be utilized for regenerative medicine applications. Moreover, it allows for combining proteins and other biological materials in a single 3D-bioprinted structure. This paper presents a standardized fabrication method of disposable nozzle connectors (DNC) for 3D bioprinting with hydrogel-based materials. This method entails 3D printing connectors with dual inlets and a single outlet to mix the material internally. The connectors are compatible with conventional Luer lock needles, offering an efficient solution for nozzle replacement. IVZK (Ac-Ile-Val-Cha-Lys-NH2) peptide-based hydrogel materials were used as a bioink with the 3D-printed DNCs. Extrusion-based 3D bioprinting was employed to print shapes of varying complexities, demonstrating potential in achieving high print resolution, shape fidelity, and biocompatibility. Post-printing of human neonatal dermal fibroblasts, cell viability, proliferation, and metabolic activity were observed, which demonstrated the effectiveness of the proposed design and process for 3D bioprinting using low-viscosity bioinks.

Biomimetic three-dimensional glioma model printed in vitro for the studies of glioma cells and neurons interactions.

1The interactions between glioma cells and neurons are important for glioma progression but are rarely mimicked and recapitulated in in vitro three-dimensional (3D) models, which may affect the success rate of relevant drug research and development. In this study, an in vitro bioprinted 3D glioma model consisting of an outer hemispherical shell with neurons and an inner hemisphere with glioma cells is proposed to simulate the natural glioma. This model was produced by extrusion-based 3D bioprinting technology. The cells survival rate, morphology, and intercellular Ca2+ concentration studies were carried out up to 5 days of culturing. It was found that neurons could promote the proliferation of glioma cells around them, associate the morphological changes of glioma cells to be neuron-like, and increase the expression of intracellular Ca2+ of glioma cells. Conversely, the presence of glioma cells could maintain the neuronal survival rate and promote the neurite outgrowth. The results indicated that glioma cells and neurons facilitated each other implying a symbiotic pattern established between two types of cells during the early stage of glioma development, which were seldom found in the present artificial glioma models. The proposed bioprinted glioma model can mimic the natural microenvironment of glioma tissue, provide an in-depth understanding of cell-cell interactions, and enable pathological and pharmacological studies of glioma.

Versatile and non-cytotoxic GelMA-xanthan gum biomaterial ink for extrusion-based 3D bioprinting

Extrusion-based 3D bioprinting allows the 3D printing of bioinks, composed of cells and biomaterials, to mimic the complex 3D hierarchical structure of native tissues. Successful 3D bioprinting requires bioinks with specific properties, such as biocompatibility, printability, and biodegradability according to the desired application. In the present work, we aimed at developing a new versatile blend of gelatin methacryloyl-xanthan gum (GelMA-XG) suitable for extrusion-based 3D bioprinting with a straightforward process. To this end, we first optimized the process of gelatin methacryloyl (GelMA) synthesis by investigating the impact of different buffer solutions on the degree of functionalization, swelling degree, and degradation rate. The addition of xanthan gum (XG) enabled further tuning of biodegradability and an improvement of GelMA printability. Specifically, an optimal concentration of XG was found through rheological characterization and printability tests. The optimized blend showed enhanced printability and improved shape fidelity as well as its degradation products turned out to be non-cytotoxic, thus laying the foundation for cell-based applications. In conclusion, our newly developed biomaterial ink is a promising candidate for extrusion-based 3D bioprinting.

Continuous and highly accurate multi-material extrusion-based bioprinting with optical coherence tomography imaging.

Extrusion-based bioprinting is a widely used approach to construct artificial organs or tissues in the medical fields due to its easy operation and good ability to combine multimaterial. Nevertheless, the current technology is limited to some printing errors when combining multi-material printing, including mismatch between printing filaments of different materials and error deposited materials (e.g., under-extrusion and overextrusion). These errors will affect the function of the printed structure (e.g., mechanical and biological properties), and the traditional manual correction methods are inefficient in time and material, so an automatic procedure is needed to improve multimaterial printing accuracy and efficiency. However, to the best of our knowledge, very few automated procedure can achieve the registration between printing filaments of different materials. Herein, we utilized optical coherence tomography (OCT) to monitor printing process and presented a multi-material static model and a time-related control model in extrusion-based multi-material bioprinting. Specifically, the multi-material static model revealed the relationship between printed filament metrics (filament size and layer thickness) and printing parameters (printing speeds or pressures) with different materials, which enables the registration of printing filaments by rapid selection of printing parameters for the materials, while time-related control model could correct control parameters of nozzles to reduce the material deposition error at connection point between nozzles in a short time. According to the experimental results of singlelayer scaffold and multi-layer scaffold, material deposition error is eliminated, and the same layer thickness between different materials of the same layer is achieved, which proves the accuracy and practicability of these models. The proposed models could achieve improved precision of printed structure and printing efficiency.

Extrusion bioprinting of cellular aggregates improves mesenchymal stem cell proliferation and differentiation

3D extrusion bioprinting brings the prospect of stem cell-based therapies in regenerative medicine. These bioprinted stem cells are expected to proliferate and differentiate to form the desired organoids into 3D structures, which is critical for complex tissue construction. However, this strategy is hampered by low reproducible cell number and viability, and organoid immaturity due to incomplete differentiation of stem cells. Hence, we apply a novel extrusion-based bioprinting process with cellular aggregates (CA) bioink, in which the encapsulated cells are precultured in hydrogels to undergo aggregation. In this study, alginate-gelatin-collagen (Alg-Gel-Col) hydrogel containing mesenchymal stem cells (MSCs) were precultured for 48 h to form CA bioink and resulted in high cell viability and printing fidelity. Meanwhile, MSCs in CA bioink showed high proliferation, stemness and lipogenic differentiative potential in contrast to that in single cell (SC) bioink and hanging drop cell spheroid (HDCS) bioink, which indicated the considerable potential for complex tissue construction. In addition, the printability and efficacy of human umbilical cord MSCs (hUC-MSCs) were further confirmed the translational potential of this novel bioprinting method.

Modeling a Dynamic Printability Window on Polysaccharide Blend Inks for Extrusion Bioprinting.

Extrusion-based bioprinting is one of the most widespread technologies due to its affordability, wide range of processable materials, and ease of use. However, the formulation of new inks for this technique is based on time-consuming trial-and-error processes to establish the optimal ink composition and printing parameters. Here, a dynamic printability window was modeled for the assessment of the printability of polysaccharide blend inks of alginate and hyaluronic acid with the intent to build a versatile predictive tool to speed up the testing procedures. The model considers both the rheological properties of the blends (viscosity, shear thinning behavior, and viscoelasticity) and their printability (in terms of extrudability and the ability of forming a well-defined filament and detailed geometries). By imposing some conditions on the model equations, it was possible to define empirical bands in which the printability is ensured. The predictive capability of the built model was successfully verified on an untested blend of alginate and hyaluronic acid chosen to simultaneously optimize the printability index and minimize the size of the deposited filament.

Convergence of 3D Bioprinting and Nanotechnology in Tissue Engineering Scaffolds.

Three-dimensional (3D) bioprinting has emerged as a promising scaffold fabrication strategy for tissue engineering with excellent control over scaffold geometry and microstructure. Nanobiomaterials as bioinks play a key role in manipulating the cellular microenvironment to alter its growth and development. This review first introduces the commonly used nanomaterials in tissue engineering scaffolds, including natural polymers, synthetic polymers, and polymer derivatives, and reveals the improvement of nanomaterials on scaffold performance. Second, the 3D bioprinting technologies of inkjet-based bioprinting, extrusion-based bioprinting, laser-assisted bioprinting, and stereolithography bioprinting are comprehensively itemized, and the advantages and underlying mechanisms are revealed. Then the convergence of 3D bioprinting and nanotechnology applications in tissue engineering scaffolds, such as bone, nerve, blood vessel, tendon, and internal organs, are discussed. Finally, the challenges and perspectives of convergence of 3D bioprinting and nanotechnology are proposed. This review will provide scientific guidance to develop 3D bioprinting tissue engineering scaffolds by nanotechnology.

Extrusion based bioprinting of alginate based multicomponent hydrogels for tissue regeneration applications: State of the art

Alginate hydrogel has plausible applications in drug delivery, wound dressing, and tissue regeneration due to its good gelation and biocompatibility properties. However, scaffolds fabricated from alginate hydrogels need more mechanical properties. Various researchers investigated improving the mechanical properties of alginate hydrogels with the addition of different natural and synthetic polymers. 3D bioprinting is an embryonic technology in the biomedical field for printing a variety of complex soft and hard tissues and organs. Extrusion-based bioprinting (EBBP) is widely used among the different methods for printing alginate hydrogels. The present review studies alginate hydrogels with a blend of natural and synthetic polymers, ceramics, and metals to improve biomechanical properties concerning different biomedical applications. Advancements in EBBP are elucidated for printing a variety of scaffolds and tissues using multimaterial alginate hydrogels. The application of machine learning is pondered for optimizing the composition of multimaterial alginate hydrogel. Additionally, the challenges and futuristic aspects are discussed to enhance bioconstruct properties.

3D-Printing of Silk Nanofibrils Reinforced Alginate for Soft Tissue Engineering.

The main challenge of extrusion 3D bioprinting is the development of bioinks with the desired rheological and mechanical performance and biocompatibility to create complex and patient-specific scaffolds in a repeatable and accurate manner. This study aims to introduce non-synthetic bioinks based on alginate (Alg) incorporated with various concentrations of silk nanofibrils (SNF, 1, 2, and 3 wt.%) and optimize their properties for soft tissue engineering. Alg-SNF inks demonstrated a high degree of shear-thinning with reversible stress softening behavior contributing to extrusion in pre-designed shapes. In addition, our results confirmed the good interaction between SNFs and alginate matrix resulted in significantly improved mechanical and biological characteristics and controlled degradation rate. Noticeably, the addition of 2 wt.% SNF improved the compressive strength (2.2 times), tensile strength (5 times), and elastic modulus (3 times) of alginate. In addition, reinforcing 3D-printed alginate with 2 wt.% SNF resulted in increased cell viability (1.5 times) and proliferation (5.6 times) after 5 days of culturing. In summary, our study highlights the favorable rheological and mechanical performances, degradation rate, swelling, and biocompatibility of Alg-2SNF ink containing 2 wt.% SNF for extrusion-based bioprinting.

Performance of hybrid gelatin-PVA bioinks integrated with genipin through extrusion-based 3D bioprinting: An in vitro evaluation using human dermal fibroblasts.

3D bioprinting technology is a well-established and promising advanced fabrication technique that utilizes potential biomaterials as bioinks to replace lost skin and promote new tissue regeneration. Cutaneous regenerative biomaterials are highly commended since they benefit patients with larger wound sizes and irregular wound shapes compared to the painstaking split-skin graft. This study aimed to fabricate biocompatible, biodegradable, and printable bioinks as a cutaneous substitute that leads to newly formed tissue post-transplantation. Briefly, gelatin (GE) and polyvinyl alcohol (PVA) bioinks were prepared in various concentrations (w/v); GE (6% GE: 0% PVA), GPVA3 (6% GE: 3% PVA), and GPVA5 (6% GE: 5% PVA), followed by 0.1% (w/v) genipin (GNP) crosslinking to achieve optimum printability. According to the results, GPVA5_GNP significantly presented at least 590.93 ± 164.7% of swelling ratio capacity and optimal water vapor transmission rate (WVTR), which is <1500 g/m2/h to maintain the moisture of the wound microenvironment. Besides, GPVA5_GNP is also more durable than other hydrogels with the slowest biodegradation rate of 0.018 ± 0.08 mg/h. The increasing amount of PVA improved the rheological properties of the hydrogels, leading the GPVA5_GNP to have the highest viscosity, around 3.0 ± 0.06 Pa.s. It allows a better performance of bioinks printability via extrusion technique. Moreover, the cross-section of the microstructure hydrogels showed the average pore sizes >100 μm with excellent interconnected porosity. X-ray diffraction (XRD) analysis showed that the hydrogels maintain their amorphous properties and were well-distributed through energy dispersive X-ray after crosslinking. Furthermore, there had no substantial functional group changes, as observed by Fourier transform infrared spectroscopy, after the addition of crosslinker. In addition, GPVA hydrogels were biocompatible to the cells, effectively demonstrating >90% of cell viability. In conclusion, GPVA hydrogels crosslinked with GNP, as prospective bioinks, exhibited the superior properties necessary for wound healing treatment.

A novel extrusion-based 3D bioprinting system for skeletal muscle tissue engineering

Three-dimensional (3D) bioprinting is an emerging technology, which turned out to be an optimal tool for tissue engineering approaches. To date, different printing systems have been developed. Among them, the extrusion-based approach demonstrated to be the most suitable for skeletal muscle tissue engineering, due to its ability to produce and deposit printing fibers in a parallel pattern that well mimic the native skeletal muscle tissue architecture. In tissue bioengineering, a key role is played by biomaterials, which must possess the key requisite of ‘printability’. Nevertheless, this feature is not often well correlated with cell requirements, such as motives for cellular adhesion and/or absorbability. To overcome this hurdle, several efforts have been made to obtain an effective bioink by combining two different biomaterials in order to reach a good printability besides a suitable biological activity. However, despite being efficient, this strategy reveals several outcomes limitations. We report here the development and characterization of a novel extrusion-based 3D bioprinting system, and its application for correction of volumetric muscle loss (VML) injury in a mouse model. The developed bioprinting system is based on the use of PEG-Fibrinogen, a unique biomaterial with excellent biocompatibility, well-suited for skeletal muscle tissue engineering. With this approach, we obtained highly organized 3D constructs, in which murine muscle progenitors were able to differentiate into muscle fibers arranged in aligned bundles and capable of spontaneously contracting when cultured in vitro. Furthermore, to evaluate the potential of the developed system in future regenerative medicine applications, bioprinted constructs laden with either murine or human muscle progenitors were transplanted to regenerate the Tibialis Anterior muscle of a VML murine model, one month after grafting.