Engineered whole cut meat-like tissue by the assembly of cell fibers using tendon-gel integrated bioprinting

Microfluidic cell carriers for cultured meat

Cultured meat aims to produce meat mass from cell culture instead of conventional livestock slaughtering. Due to anchorage-dependent and 3D culturing manner of cells, cell carriers are critical in cultured meat. Various cell carriers have been used for expansion of seed cells and cultured meat tissue construction, such as commercial microcarriers, electrospray microspheres, and 3D-printed microfibers, but facing suboptimal effect of cell growth and specific differentiation. Compared to traditional methods, microfluidics can purposefully fabricate cell carriers with diverse structures and components, thereby achieving adequate simulation of natural muscle. Research has shown that microfluidic fibrous carriers possessed excellent effect in cultured meat tissue construction. This review overviews application and potential of microfluidic cell carriers in cultured meat. Starting with introduction of materials for carrier construction, we discuss limitations of traditional cell carriers and focus on microfluidic carrier in cultured meat. Finally, we present challenges and perspectives of microfluidics for cultured meat.

Constructing anisotropic and strong polysaccharide-based hydrogels with stretching-dehydration strategy: Effect of sodium alginate, pectin, gellan gum, and curdlan

Polysaccharide-based hydrogels are widely utilized in the food industry and materials science due to their safety and abundance from natural sources. However, their functionality is often limited by poor mechanical properties, primarily due to their simple and isotropic structures. In this study, the stretching-dehydration (SD) processing was applied to create anisotropic structure and enhance the mechanical properties in polysaccharide-based hydrogels, specifically sodium alginate (SA), pectin (PE), gellan gum (GG), and curdlan (CU). Among these, low molecular weight sodium alginate (SA-L) hydrogel exhibited notable stretching-induced anisotropy and structural stability during dehydration. Furthermore, increasing the controlled strains (CSN) could improve anisotropy, stretching strength, and Young's modulus which reached up to 100 MPa in anisotropic SA-L hydrogel. The anisotropic hydrogels closely mimicked the microstructure of whole-muscle foods. Sensory evaluations highlighted the enhanced chewiness and hardness, suggesting the anisotropic hydrogels are promising candidates for emulating whole-muscle textures. This work highlights the potential of anisotropic hydrogels produced through simple SD treatment as advanced materials for both food and biomimetic applications.

Self-Healing Scaffolding Technology with Strong, Reversible Interactions under Physiological Conditions for Engineering Marbled Cultured Meat

Cultured meat offers a sustainable alternative to animal farming, with the potential to reduce environmental impacts and improve food security. However, recapitulating natural meat marbling remains a significant challenge. This study presents a straightforward technology for achieving precise marbling patterns in large-scale cultured meat using self-healing hydrogels containing boronic acid-conjugated chitosan. Unlike conventional hydrogels, which require nonphysiological conditions for strong, reversible bonding, our system achieves robust reversible bonding at neutral pH through a unique mechanism: the nucleophilic groups of chitosan facilitate boronic acid-diol bond formation, exhibiting half the strength of a typical covalent bond, as demonstrated by nanomechanics analysis. The hydrogels form dual reversible networks of boronic acid-diol and hydrogen bonds, enabling self-healing and tunable stiffness. Biocompatibility studies confirm that they support the growth of mouse-derived cells and bovine-derived primary muscle cells. Each hydrogel variant optimizes mechanotransduction for the distinct requirements of fat or muscle cell culture and differentiation. This self-healing scaffolding technology enables the seamless assembly of muscle and fat monocultures into centimeter-thick meat with micrometer-scale marbling patterns, tailoring organoleptic properties and nutritional profiles without the need for meat glues or processing equipment.

Cost-effective production of meaty aroma from porcine cells for hybrid cultivated meat

Cultivated meats are typically hybrids of animal cells and plant proteins, but their high production costs limit their scalability. This study explores a cost-effective alternative by hypothesizing that controlling the Maillard and lipid thermal degradation reactions in pure cells can create a meaty aroma that could be extracted from minimal cell quantities. Using spontaneously immortalized porcine myoblasts and fibroblasts adapted to suspension culture with a 1 % serum concentration, we developed a method to isolate flavor precursors via freeze-thawing. Thermal reaction conditions were optimized to enhance aroma compound production. Chemical profiling demonstrates that myoblasts produce an aroma profile closer to pork meat than fibroblasts, although serum reduction decreased aroma yield. Sensory analysis supported these findings. Incorporating the optimized aroma extract - derived from just 1.2 % (w/w) cells - into plant proteins resulted in a hybrid cultivated meat with 78.5 % sensory similarity to pork meat, but with a significant 80 % reduction in production costs.

Glycyrrhiza uralensis crude water extract and licochalcone A and B to enhance chicken muscle satellite cell differentiation for cultured meat production

Muscle satellite cells (MSCs) are the most commonly used cells in cultured meat research and development. Enhancing MSC proliferation and differentiation while reducing cell culture costs is requisite to commercializing cultured meat. This study explored the effects of Glycyrrhiza uralensis crude water extract (GU-CWE) and licochalcone A and B (Lic A or B) on the proliferation and differentiation of chicken, bovine, and porcine MSCs. While GU-CWE and Lic A and B had negligible effects on bovine and porcine MSCs, GU-CWE significantly enhanced chicken MSC differentiation, and Lic A and B promoted both the proliferation and differentiation of chicken MSCs. Furthermore, GU-CWE was found to mitigate reactive oxygen species activity during chicken MSC differentiation and promote cell proliferation and adhesion in spheroid culture, thereby maintaining a spherical shape. Collectively, this study suggests that GU-CWE and Lic A and B can significantly reduce costs and safely increase the productivity of chicken MSCs in cultured meat production processes.

Advances in Microfluidics-Enabled Dimensional Design of Micro-/Nanomaterials for Biomedical Applications: A Review

Biomedical materials are of great significance for preventing and treating major diseases and protecting human health. At present, more stringent requirements have been put forward for the preparation methods and dimension control of biomedical materials based on the urgent demand for high-performance biomedical materials, especially the existence of various physiological size thresholds in vitro/in vivo. Microfluidic platforms break the limitations of traditional micro-/nanomaterial synthesis, which provide a miniaturized and highly controlled environment for size-dependent biomaterials. In this review, the basic conceptions and technical characteristics of microfluidics are first described. Then the syntheses of biomedical materials with different dimensions (0D, 1D, 2D, 3D) driven by microfluidics have been systematically summarized. Meanwhile, the applications of microfluidics-driven biomedical materials, including diagnosis, anti-inflammatory, drug delivery, antibacterial, and disease therapy, are discussed. Furthermore, the challenges and developments in the research field are further proposed. This work is expected to facilitate the convergence between the bioscience and engineering communities and continue to contribute to this emerging field.

[3D printing in surgery: relevance of technology maturity assessment in bioprinting research studies]

Biological 3D printing (bioprinting) is an extension of what is defined as additive manufacturing in the American Society for Testing and Materials (ASTM) and International Organization for Standardization (ISO) standards and is based on the automated printing of living cells and biomaterials. Researchers and experts in the field of biomaterial science, tissue engineering and regenerative medicine (TE&RM) are constantly pointing to the potential of biological 3D printing and scientific articles regularly announce the imminent clinical application. We argue in this article that these announcements are often premature and counterproductive as they focus heavily on technological progress but regularly ignore the critical stages that need to be completed in order to successfully translate a technology into the healthcare market. The technology readiness level (TRL) scale is a potentially useful tool for measuring the relative maturity of a technology in terms of overcoming a series of critical milestones. We propose an adaptation of the TRL scale and use it to discuss the current state of research on biological 3D printing. Finally, we provide specific recommendations for optimizing future research projects to pave the way for clinical applications of biological 3D printing and thus achieve a direct positive impact on surgical patient care.

Morphology and functionality in biomimetic cultured meat produced from various cellular origins

Alternative meat production technologies offer the potential to alleviate many of the ethical, environmental, and public health concerns associated with conventional meat production. Cultured meat produced using cell culture technology promises to become a viable alternative to animal-raised meat for the future of the food industry. The process of cultured meat production relies on cell sources harvested from livestock such as bovine, swine, and chicken. Previously, we have developed a primary culture method allowing the efficient collection of myogenic cells from bovine cheek meat. Although the myogenic cells were used as a cell source to produce bovine muscle tissues with biomimetic morphological and functional characteristics in a "biomimetic cultured beef" product, it is not certain that the cells harvested from cheek meat are the best choice as a cell source for cultured meat. Moreover, there are no previous studies investigating the appropriate selection of cell sources for producing cultured meat on demand. In this study, myogenic cells were harvested from three different cuts of swine muscle (cheek, loin, and ham) to assess the impact of each cell type and understand how to best select from the various cuts of muscle. Although it was expected that the three types of swine myogenic cells have different characteristics based on each meat cut, they all proliferated similarly while maintaining the expression of myogenic markers (MyoD, Myf5) during repeated passages. They also had differentiation ability at the same level in the first step of differentiation (fusion of myogenic cells to form myotube) in vitro. Therefore, the myogenic cells from different cuts of muscle fundamentally expressed the same characteristics in normal 2D culture. On the other hand, since our tissue engineering method allowed us to produce morphologically and functionally biomimetic muscle tissues, we successfully produced contractile muscle tissues with native-like aligned structures from all types of the swine myogenic cells. Through the tissue maturation process, the three types of myogenic cells also showed site-specificity in the further differentiation step (maturation into contractile myofibers). The myogenic cells harvested from ham formed significantly thicker myofibers in "ham muscle tissues", compared with that in "cheek muscle tissues" and "loin muscle tissues". This suggested that swine myogenic cells have some unique characteristics depending on the different cuts of muscle. On the other hand, there was no significant difference in contractile functionality between the three types of muscle tissues. Although further experiments will be required to deepen our understanding of the similarities and differences of site-specific myogenic cells, we believe that the results of this study are important to selectively produce various types of cultured meat and ultimately become the conventional meat in the future.

Programmable embedded bioprinting for one-step manufacturing of arterial models with customized contractile and metabolic functions

Replicating the contractile function of arterial tissues in vitro requires precise control of cell alignment within 3D structures, a challenge that existing bioprinting techniques struggle to meet. In this study, we introduce the voxel-based embedded construction for tailored orientational replication (VECTOR) method, a voxel-based approach that controls cellular orientation and collective behavior within bioprinted filaments. By fine-tuning voxel vector magnitude and using an omnidirectional printing trajectory, we achieve structural mimicry at both the macroscale and the cellular alignment level. This dual-scale approach enhances vascular smooth muscle cell (VSMC) function by regulating contractile and synthetic pathways. The VECTOR method facilitates the construction of 3D arterial structures that closely replicate natural coronary architectures, significantly improving contractility and metabolic function. Moreover, the resulting multilayered arterial models (AMs) exhibit precise responses to pharmacological stimuli, similar to native arteries. This work highlights the critical role of structural mimicry in tissue functionality and advances the replication of complex tissues in vitro.

A review on the characterization of edible scaffolds for cultured meat: Physical, chemical, biocompatibility, and food safety evaluation methods

Scaffolds are three-dimensional biomaterials that act as structural blueprint for cultured meat precursor cells. The advancement of scaffold fabrication techniques and the development of novel scaffolds specifically designed for cultured meat are evident in numerous scaffold-based cultured meat reports, highlighting the advantages of the scaffolds using different characterization and evaluation techniques encompassing the physical, mechanical, chemical, and biological features of the scaffolds. Considering the potential of scaffolds to be included in cultured meat products, standardization of evaluation techniques could aid in preventing misrepresentation and possible food safety concerns in cultured meat production. Thus, appropriate food safety evaluation methods must be included to properly establish scaffolds as food safe or edible. The standardization of scaffold evaluation methods could aid in increasing the dependability and consumption of scaffold-based cultured meat.

Scalable tissue biofabrication via perfusable hollow fiber arrays for cultured meat applications

Creating perfusable channels within engineered tissues is crucial for the development of large-scale tissues. Unfortunately, existing technologies have not achieved uniformly distributed, perfusable networks on a large scale. To overcome this, we developed a method using a hollow fiber bioreactor (HFB) equipped with an array of closely packed semipermeable hollow fibers that function as artificial circulation systems, ensuring uniform nutrient and oxygen distribution throughout the tissue. Furthermore, the HFB includes microfabricated anchors for promoting cell alignment. When using active perfusion, biofabricated centimeter-scale chicken muscle tissue exhibited an elevated level of marker protein expression and sarcomere formation throughout the tissue, along with improved texture and flavor. In addition, a robotic-assisted fiber threading system was developed to achieve efficient assembly of the HFBs. Future full automation of this approach may revolutionize both the cultured meat industry and the tissue engineering field, which aims to create large-scale, tissue-engineered organs.

A novel solution for real-timein-situcell distribution monitoring in 3D bioprinting via fluorescence imaging

3D bioprinting is rapidly evolving as a transformative technology for constructing biological tissues with precise cell and bioink placement. However, ensuring the quality and viability of bioprinted structures presents significant challenges, highlighting the need for advanced monitoring systems. Our study introduces a space-efficient, non-invasive approach for real-time,in-situmonitoring of cell dispersion in bioprinted constructs. Utilizing a novelin-situfluorescence microscopy technique, we employ nanoparticles for cell tagging and integrate a compact digital microscope into the bioprinter for layer-by-layer imaging, significantly saving space and weight to make the solution adaptable to any commercial bioprinter. This method enhancesin-situanalysis by combining data from the fluorescence system with conventional visible spectrum imaging. The synergy of these datasets provides a detailed method to examine cell dispersion and facilitates continuous monitoring during the bioprinting process. This allows for the immediate identification and correction of irregularities in cell deposition. Our approach aims to advance 3D bioprinting, setting new standards for the reliability and efficiency of bioprinted structures.

Evaluation of the Gelation Characteristics and Printability of Edible Filamentous Fungi Flours and Protein Extracts

There is a pressing need to produce novel food ingredients from sustainable sources to support a growing population. Filamentous fungi can be readily cultivated from low-cost agricultural byproducts to produce functional proteins for food biomanufacturing of structured products. However, there is a lack of scientific knowledge on the gelling characteristics of fungal proteins or their potential in additive biomanufacturing. Therefore, this study investigated the feasibility of utilizing fungal protein extracts and flours from Aspergillus awamori, Pleurotus ostreatus, Auricularia auricula-judae as sole gelling agents in 3D-printed products. Protein extracts were successfully prepared using the alkaline extraction-isoelectric precipitation method and successful physical gels were created after heating and cooling. Results indicated that shear-thinning gel materials could be formed with acceptable printability at mass inclusion rates between 15% and 25% with the best performance obtained with P. ostreatus protein extract at 25% inclusion. A. auricula-judae demonstrated promising rheological characteristics but further optimization is needed to create homogeneous products appropriate for extrusion-based 3D printing. This work provides valuable insights for continued development of 3D-printed foods with filamentous fungi.

Emerging Microfluidic Building Blocks for Cultured Meat Construction

Cultured meat aims to produce meat mass by culturing cells and tissues based on the muscle regeneration mechanism, and is considered an alternative to raising and slaughtering livestock. Hydrogel building blocks are commonly used as substrates for cell culture in tissue engineering and cultured meat because of their high water content, biocompatibility, and similar three-dimensional (3D) environment to the cellular niche in vivo. With the characteristics of precise manipulation of fluids, microfluidics exhibits advantages in the fabrication of building blocks with different structures and components, which have been widely applied in tissue regeneration. Microfluidic building blocks show promising prospects in the field of cultured meat; however, few reviews on the application of microfluidic building blocks in cultured meat have been published. This review outlines the recent status and prospects of the use of microfluidic building blocks in cultured meat. Starting with the introduction of cells and materials for cultured meat tissue construction, we then describe the diverse structures of the fabricated building blocks, including microspheres, microfibers, and microsphere-microfiber hybrid systems. Next, the stacking strategies for tissue construction are highlighted in detail. Finally, challenges and future prospects for developing microfluidic building blocks for cultured meat are discussed.

Development of special nutritional balanced food 3D printing products based on the mixing of animals/plants materials: research progress, applications, and trends

Food 3D printing brings food processing technology into the digital age. This is a vast field that can provide entertainment experience, personalized food and specific nutritional needs. However, the limited availability of suitable food raw materials has restricted the extensive use of 3D food printing processing technique. The search for novel nutritious and healthy food materials that meet the demand for 3D food printing processing technology is core of the sustainable development of this emerging technology. The printing mechanism, precise nutrition, future outlooks and challenges of 3D food printing technology application in hybrid plant and animal food materials are also analyzed.The results demonstrate that selecting suitable animal and plant materials and mixing them into 3D food printing ingredients without adding food additives can result in printable inks, which can also improve the nutritive value and eating quality of 3D food printed products. Sustainability of novel food materials such as animal cell culture meat and microbial protein mixed with conventional food materials to realize 3D printed food can be a potential research direction. Some other issues should also be considered in future research, such as evaluation of the nutritional efficacy of the product, product stability, shelf life, production efficiency and convenience of process operation.

Towards more realistic cultivated meat by rethinking bioengineering approaches

Cultivated meat (CM) refers to edible lab-grown meat that incorporates cultivated animal cells. It has the potential to address some issues associated with real meat (RM) production, including the ethical and environmental impact of animal farming, and health concerns. Recently, various biomanufacturing methods have been developed to attempt to recreate realistic meat in the laboratory. We therefore overview recent achievements and challenges in the production of CM. We also discuss the issues that need to be addressed and suggest additional recommendations and potential criteria to help to bridge the gap between CM and RM from an engineering standpoint.

Bio-Orchestration of Cellular Organization and Human-Preferred Sensory Texture in Cultured Meat

For cultured meat to effectively replace traditional meat, it is essential to develop scaffolds that replicate key attributes of real meat, such as taste, nutrition, flavor, and texture. However, one of the significant challenges in replicating meat characteristics with scaffolds lies in the considerable gap between the stiffness preferred by cells and the textural properties desired by humans. To address this issue, we focused on the microscale environment conducive to cell growth and the macro-scale properties favored by humans. This led to the development of the adaptive bio-orchestrating anisotropic scaffold (ABS), which satisfies both cellular and human requirements. The ABS is produced using the anisotropic freeze-initiated ion coordination method, which sequentially aligns and enhances the fibril structure of food-derived proteins, effectively bridging the gap between cellular and culinary perspectives. Notably, the microenvironments of the ABS exhibited exceptional myoblast cell differentiation, with macro-scale 3D mechanical textures that are consistent regardless of the chewing direction, due to the aligned fibril and cell structure. The ABS containing bovine myotubes demonstrated a mechanical texture nearly identical to that of beef sirloins.

Growing meat on autoclaved vegetables with biomimetic stiffness and micro-patterns

Cultured meat needs edible bio-scaffolds that provide not only a growth milieu for muscle and adipose cells, but also biomimetic stiffness and tissue-sculpting topography. Current meat-engineering technologies struggle to achieve scalable cell production, efficient cell differentiation, and tissue maturation in one single culture system. Here we propose an autoclaving strategy to transform common vegetables into muscle- and adipose-engineering scaffolds, without undergoing conventional plant decellularization. We selected vegetables with natural anisotropic and isotropic topology mimicking muscle and adipose microstructures respectively. We further adjusted vegetable stiffness by autoclaving, to emulate the mechanical properties of animal tissues. Autoclaved vegetables preserve rich cell-affinitive moieties, yielding a good cell culture effect with simplified processing. Autoclaved Chinese chive and Shiitake mushroom with anisotropic micro-patterns support the scalable expansion of muscle cells, improved cell alignment and myogenesis. Autoclaved isotropic loofah encourages adipocyte proliferation and lipid accumulation. Our engineered muscle- and fat-on-vegetables can further construct meat stuffing or layered meat chips. Autoclaved vegetables possess tissue-mimicking stiffness and topology, and bring biochemical benefits, operational ease, cost reduction and bioreactor compatibility. Without needing decellularization, these natural biomaterials may see scale-up applications in meat analog bio-fabrication.

A Review on the Application of Animal-Based Materials Using Three-Dimensional (3D) Printing and Protein Restructuring Technologies

Production of alternative proteins is crucial for the development of future protein resources. This study explored the creation of sustainable animal resources by combining extrusion molding and three-dimensional (3D) printing technologies. Extrusion effectively organizes vegetable proteins at high temperatures and pressures to replicate meat-like textures, and high-moisture extrusion successfully mimics the fiber structure of conventional meat. However, many meat analogs products still differ from conventional meat in terms of sensory properties such as texture, juiciness, and flavor, indicating the need for quality improvement. Researchers have leveraged 3D printing technology to incorporate fat analogs and enhance the appearance and texture through muscle fiber simulation. This technology allows for precise arrangement of muscle fibers, formation of adipose tissue, and marbling, thereby improving the overall sensory experience. By combining extrusion and 3D printing, we can enhance the nutritional and organoleptic qualities of meat analogs, ultimately meeting consumer expectations and achieving a balance between plant- and animal-based materials.

Effect of active carbonyl-carboxyl ratio on dynamic Schiff base crosslinking and its modulation of high-performance oxidized starch-chitosan hydrogel by hot extrusion 3D printing

The quest to develop 3D starch-based printing hydrogels for the controlled release of active substances with excellent mechanical and printing properties has gained significant attention. This work introduced a facile method based on crosslinking via Schiff base reaction for preparing bicomponent hydrogels. The method involved the utilization of customizable oxidized starch (OS) and chitosan (CS), enabling superior printing performance through the precise control of various active carbonyl-carboxyl ratios (ACR, 2:1, 1:1, and 2:3, respectively) of OS. OS-CS hydrogel (OSC) with an ACR level of 2:1 (OS-2-y%CS) underwent rearrangement during printing environment, fostering increased Schiff base reaction with a higher crosslinking degree and robust high structural recovery (>95 %). However, with decreasing ACR levels (from 2:1 to 2:3), the printing performance and mechanical strength of printed OSC (POSC) declined due to lower Schiff base bonds and increased phase separation. Compared with printed OS, POS-2-2%CS exhibited a remarkable 1250.52 % increase in tensile strength and a substantial 2424.71 % boost in compressive strength, enhanced shape fidelity and notable self-healing properties. Moreover, POS-2-2%CS exhibited stable diffusive drug release, showing potential application in the pH-responsive release of active substances. Overall, controlling the active carbonyl-carboxyl ratios provided an efficient and manageable approach for preparing high-performance 3D-printed hydrogels.

Removal-Free and Multicellular Suspension Bath-Based 3D Bioprinting

Suspension bath-based 3D bioprinting (SUB3BP) is effective in creating engineered vascular structures. The transfer of oxygen and nutrients via engineered vascular networks is necessary for tissue or organ survival and integration following transplantation. Existing SUB3BP techniques face challenges in fabricating hierarchical structures with multicellular organization, including issues related to suspension bath removal, restricted material choices, and low accuracy. A next-generation SUB3BP technique that is removal-free and multicellular is presented. A simple, storable, stable, and scalable starch hydrogel design leverages the diverse spectrum of hydrogels available for use in SUB3BP. Starch granules (8.1 µm) create vascular structures with minimal surface roughness (2.5 µm) that simulate more natural vessel walls compared to prior research. The development of cells and organoids, as well as the bioprinting of multicellular skin models with vasculature, demonstrates that starch suspension baths eliminate the removal process and have the potential for fabricating artificial tissue with a hierarchical structure and multicellular distribution.

Highly aligned myotubes formation of piscine satellite cells in 3D fibrin hydrogels of cultured meat

Currently, various cultured meat products, including chicken, beef and pork, have been developed. However, established methods for production cultured fish meat with highly aligned myotubes are still lack. In this study, we introduced a culture method based on high-biocompatibility fibrin hydrogels with an easy-to-use tissue mold for obtaining cultured fish fillets that closely mimicked the structure of natural fish fillets. Results showed that highly aligned myotubes were observed within the muscle bundles culturing in the tissue mold. The myotube fusion index was also increased to 72.65 %. Furthermore, key differentiation genes (desmin, myosin light chain kinase, myocilin) were up-regulated in the tissue mold group. Transcriptomic analysis further supported the effectiveness of method in promoting myoblast fusion. Stiffness of the muscle bundles was also positively impacted by the tissue mold. Ultimately, sensory and nutritional characteristics of natural and cultured fish fillets were compared, revealing that cultured fish fillets prepared from the tissue mold was closer to natural fish fillets in sensory characteristic, and there were still some gaps with natural fish fillets in nutritional characteristic. Overall, our findings suggest that optimizing culture methods can help bridge some gaps between natural meat and cultured meat, facilitating the development of cultured fish meat.

Dynamically cultured, differentiated bovine adipose-derived stem cell spheroids as building blocks for biofabricating cultured fat

Cultured or cultivated meat, animal muscle, and fat tissue grown in vitro, could transform the global meat market, reducing animal suffering while using fewer resources than traditional meat production and no antimicrobials at all. To ensure the appeal of cultured meat to future customers, cultured fat is essential for achieving desired mouthfeel, taste, and texture, especially in beef. In this work we show the establishment of primary bovine adipose-derived stem cell spheroids in static and dynamic suspension culture. Spheroids are successfully differentiated using a single-step protocol. Differentiated spheroids from dynamic cultures maintain stability and viability during 3D bioprinting in edible gellan gum. Also, the fatty acid composition of differentiated spheroids is significantly different from control spheroids. The cells are cultured antibiotic-free to minimize the use of harmful substances. This work presents a stable and bioprintable building block for cultured fat with a high cell density in a 3D dynamic cell culture system.

Why bioprinting in regenerative medicine should adopt a rational technology readiness assessment

Bioprinting is an annex of additive manufacturing, as defined by the American Society for Testing and Materials (ASTM) and International Organization for Standardization (ISO) standards, characterized by the automated deposition of living cells and biomaterials. The tissue engineering and regenerative medicine (TE&RM) community has eagerly adopted bioprinting, while review articles regularly herald its imminent translation to the clinic as functional tissues and organs. Here we argue that such proclamations are premature and counterproductive; they place emphasis on technological progress while typically ignoring the critical stage-gates that must be passed through to bring a technology to market. We suggest the technology readiness level (TRL) scale as a valuable metric for gauging the relative maturity of a bioprinting technology in relation to how it has passed a series of key milestones. We suggest guidelines for a bioprinting-oriented scale and use this to discuss the state-of-the-art of bioprinting in regenerative medicine (BRM) today. Finally, we make corresponding recommendations for improvements to BRM research that would support its progression to clinical translation.

A narrative review: 3D bioprinting of cultured muscle meat and seafood products and its potential for the food industry

The demand for meat and seafood products has been globally increasing for decades. To address the environmental, social, and economic impacts of this trend, there has been a surge in the development of three-dimensional (3D) food bioprinting technologies for lab-grown muscle food products and their analogues. This innovative approach is a sustainable solution to mitigate the environmental risks associated with climate change caused by the negative impacts of indiscriminative livestock production and industrial aquaculture. This review article explores the adoption of 3D bioprinting modalities to manufacture lab-grown muscle food products and their associated technologies, cells, and bioink formulations. Additionally, various processing techniques, governing the characteristics of bioprinted food products, nutritional compositions, and safety aspects as well as its relevant ethical and social considerations, were discussed. Although promising, further research and development is needed to meet standards and translate into several industrial areas, such as the food and renewable energy industries. In specific, optimization of animal cell culture conditions, development of serum-free media, and bioreactor design are essential to eliminate the risk factors but achieve the unique nutritional requirements and consumer acceptance. In short, the advancement of 3D bioprinting technologies holds great potential for transforming the food industry, but achieving widespread adoption will require continued innovation, rigorous research, and adherence to ethical standards to ensure safety, nutritional quality, and consumer acceptance.

Effect of Chicken Age on Proliferation and Differentiation Abilities of Muscle Stem Cells and Nutritional Characteristics of Cultured Meat Tissue

This study aimed to investigate effects of chicken age on proliferation and differentiation capacity of muscle satellite cells (MSCs) and to determine total amino acid contents of cultured meat (CM) produced. Chicken MSCs (cMSCs) were isolated from hindlimb muscles of broiler chickens at 5-week-old (5W) and 19-embryonic-day (19ED), respectively. Proliferation abilities (population doubling time and cell counting kit 8) of cMSCs from 19ED were significantly higher than those from 5W (p<0.05). Likewise, both myotube formation area and expression of myosin heavy chain heavy of cMSCs from 19ED were significantly higher than those from 5W (p<0.05). After cMSCs were serially subcultured for long-term cultivation in 2D flasks to produce cultured meat tissue (CMT), total amino acid contents of CMT showed no significant difference between 5W and 19ED chickens (p>0.05). This finding suggests that cMSCs from chicken embryos are more suitable for improving the production efficiency of CM than those derived from young chickens.

State of the art, challenges, and future prospects for the multi-material 3D printing of plant-based meat

The emergence of innovative plant-based meat analogs, replicating the flavor, texture, and appearance of animal meat cuts, is deemed crucial for sustainably feeding a growing population while mitigating the environmental impact associated with livestock farming. Multi-material 3D food printing (MM3DFP) has been proposed as a potentially disruptive technology for manufacturing the next generation of plant-based meat analogs. This article provides a comprehensive review of the state of the art, addressing various aspects of 3D printing in the realm of plant-based meat. The disruptive potential of printed meat analogs is discussed with particular emphasis on protein-rich, lipid-rich, and blood-mimicking food inks. The printing parameters, printing requirements, and rheological properties at the different printing stages are addressed in detail. As food rheology plays a key role in the printing process, an appraisal of this subject is performed. Post-printing treatments are assessed based on the extent of improvement in the quality of 3D-printed plant-based meat analogs. The meat-mimicking potential is revealed through sensory attributes, such as texture and flavor. Furthermore, there has been limited research into food safety and nutrition. Economically, the 3D printing of plant-based meat analogs demonstrates significant market potential, contingent upon innovative decision-making strategies and supportive policies to enhance consumer acceptance. This review examines the current limitations of this technology and highlights opportunities for future developments.

Enhancing the palatability of cultivated meat

Cultivated meat (CM) has transitioned from a futuristic concept to a present reality, with select products approved for consumption and sale in Singapore, Israel, and the USA. This evolution has emphasized scalable, cost-effective, and sustainable production, as well as navigation of regulatory pathways. As CM develops, a crucial challenge lies in delivering products that are highly appealing to consumers. Central to this will be refining CM palatability, a term encompassing food's taste, aroma, texture, tenderness, juiciness, and color. We explore the scientific and engineering approaches to producing palatable CM, including cell-line selection, cell differentiation, and post-processing techniques. This includes a discussion of the structural and compositional properties of meat that are intrinsically coupled to palatability.

Assessment of Health Values, Beliefs, Norms, and Behavior towards Consumption Intention of 3D-Bioprinted Meat

Continuous innovation in product development further enhances consumer appeal and contributes to a more sustainable and ethical food system. This study used the health belief model (HBM) and value-belief-norm (VBN) theory to investigate the customer perceptions of and intentions towards 3D-bioprinted meat. Specifically, this study examined consumer behavior factors using higher-order partial least squares structural equation modeling (PLS-SEM). Data were collected from 738 meat consumers through online survey questions, distributed among social groups and face-to-face distribution-limiting only to respondents who are familiar with 3D-bioprinted meats. Using a filtering question, only those who are familiar with and have knowledge of the topic were considered valid respondents. Based on the results, all variables under the integrated theories were deemed significant. Consumers' perceptions of 3D-bioprinted meat are also shaped by altruism, egoism, biospheric concern, and willingness to change. The findings revealed that buyers rationally choose benefits over social or personal values. The study emphasized educating consumers, being transparent about production, and constantly innovating for higher acceptance of 3D-bioprinted meat. In order to foster consumer confidence, it is essential to prioritize transparency in the production process, encompassing information regarding sourcing and manufacturing methods. Certifications that validate safety and quality standards serve to reinforce this notion. In addition, the implementation of competitive pricing strategies has the potential to enhance the accessibility of 3D-bioprinted meat, whereas industry partnerships can aid in distribution operations and improve market visibility-all of which extend the practical implications developed for this study. Moreover, the foundation of the integrated framework promotes its extension and application outside technology-based meat production. This could also be considered and utilized among other studies on developed food and food consumption.

Current challenges of alternative proteins as future foods

Global demand for food is expected to nearly double by 2050. Alternative proteins (AP) have been proposed as a sustainable solution to provide food security as natural resources become more depleted. However, the growth and consumer intake of AP remains limited. This review aims to better understand the challenges and environmental impacts of four main AP categories: plant-based, insect-based, microbe-derived, and cultured meat and seafood. The environmental benefits of plant-based and insect-based proteins have been documented but the impacts of microbe-derived proteins and cultured meat have not been fully assessed. The development of alternative products with nutritional and sensory profiles similar to their conventional counterparts remains highly challenging. Furthermore, incomplete safety assessments and a lack of clear regulatory guidelines confuse the food industry and hamper progress. Much still needs to be done to fully support AP utilization within the context of supporting the drive to make the global food system sustainable.

Embedded three-dimensional printing of thick pea-protein-enriched constructs for large, customized structured cell-based meat production

Recent 3D-printing research showed the potential of using plant-protein-enriched inks to fabricate cultivated meat (CM) via agar-based support baths. However, for fabricating large, customized, structured, thick cellular constructs and further cultivation, improved 3D-printing capabilities and diffusion limit circumvention are warranted. The presented study harnesses advanced printing and thick tissue engineering concepts for such purpose. By improving bath composition and altering printing design and execution, large-scale, marbled, 0.5-cm-thick rib-eye shaped constructs were obtained. The constructs featured stable fibrous architectures comparable to those of structured-meat products. Customized multi-cellular constructs with distinct regions were produced as well. Furthermore, sustainable 1-cm-thick cellular constructs were carefully designed and produced, which successfully maintained cell viability and activity for 3 weeks, through the combined effects of void-incorporation and dynamic culturing. As large, geometrically complex construct fabrication suitable for long-term cellular cultivation was demonstrated, these findings hold great promise for advancing structured CM research.

Omnidirectional anisotropic embedded 3D bioprinting

Anisotropic microstructures resulting from a well-ordered arrangement of filamentous extracellular matrix (ECM) components or cells can be found throughout the human body, including skeletal muscle, corneal stroma, and meniscus, which play a crucial role in carrying out specialized physiological functions. At present, due to the isotropic characteristics of conventional hydrogels, the construction of freeform cell-laden anisotropic structures with high-bioactive hydrogels is still a great challenge. Here, we proposed a method for direct embedded 3D cell-printing of freeform anisotropic structure with shear-oriented bioink (GelMA/PEO). This study focuses on the establishment of an anisotropic embedded 3D bioprinting system, which effectively utilizes the shear stress generated during the extrusion process to create cells encapsulating tissues with distinct anisotropy. In conjunction with the water-solubility of PEO and the in-situ encapsulation effect provided by the carrageenan support bath, high-precise cell-laden bioprinting of intricate anisotropic and porous bionic artificial tissues can be effectively implemented in one-step. Additionally, anisotropic permeable blood vessel has been taken as a representation to validate the effectiveness of the shear-oriented bioink system in fabricating intricate structures with distinct directional characteristics. Lastly, the successful preparation of muscle patches with anisotropic properties and their guiding role for cell cytoskeleton extension have provided a significant research foundation for the application of the anisotropic embedded 3D bioprinting system in the ex-vivo production and in-vivo application of anisotropic artificial tissues.

Engineering Considerations on Large-Scale Cultured Meat Production

In recent decades, cultured meat has received considerable interest as a sustainable alternative to traditional meat products, showing promise for addressing the inherent problems associated with conventional meat production. However, current limitations on the scalability of production and extremely high production costs have prevented their widespread adoption. Therefore, it is important to develop novel engineering strategies to overcome the current limitations in large-scale cultured meat production. Such engineering considerations have the potential for advancements in cultured meat production by providing innovative and effective solutions to the prevailing challenges. In this review, we discuss how engineering strategies have been utilized to advance cultured meat technology by categorizing the production processes of cultured meat into three distinct steps: (1) cell preparation; (2) cultured meat fabrication; and (3) cultured meat maturation. For each step, we provide a comprehensive discussion of the recent progress and its implications. In particular, we focused on the engineering considerations involved in each step of cultured meat production, with specific emphasis on large-scale production.

Scaffolding fundamentals and recent advances in sustainable scaffolding techniques for cultured meat development

In cultured meat (CM) production, Scaffolding plays an important role by aiding cell adhesion, growth, differentiation, and alignment. The existence of fibrous microstructure in connective and muscle tissues has attracted considerable interest in the realm of tissue engineering and triggered the interest of researchers to implement scaffolding techniques. A wide array of research efforts is ongoing in scaffolding technologies for achieving the real meat structure on the principality of biomedical research and to replace serum free CM production. Scaffolds made of animal-derived biomaterials are found efficient in replicating the extracellular matrix (ECM), thus focus should be paid to utilize animal byproducts for this purpose. Proper identification and utilization of plant-derived scaffolding biomaterial could be helpful to add diversified options in addition to animal derived sources and reduce in cost of CM production through scaffolds. Furthermore, techniques like electrospinning, modified electrospinning and 3D bioprinting should be focused on to create 3D porous scaffolds to mimic the ECM of the muscle tissue and form real meat-like structures. This review discusses recent advances in cutting edge scaffolding techniques and edible biomaterials related to structured CM production.

Cell-Cultured Fish Meat via Scale-Up Expansion of Carassius auratus Skeletal Muscle Cells Using Edible Porous Microcarriers and Quality Evaluation

Emerging technologies for cell-cultured fish meat as an environmentally friendly protein source for humans still have many obstacles, including large-scale production of high-quality cells, differentiation and bioassembly of cellular material, and improvement of the quality of meat products. Here, we used edible porous microcarriers as scaffolds to support scalable skeletal muscle cell expansion to prepare centimeter-scale cell-cultured fish (CCM) of Carassius auratus for the first time. The quality of CCM was assessed by analyzing the texture, nutrition, flavor, and safety. The results indicated that CCM demonstrated a softer texture than natural fish due to a high moisture content. CCM contained higher protein and lower fat contents, with no significant difference in energy from natural golden crucian carp meat (NGM). CCM had better digestible properties, and 17 volatile components were identified in CCM, ten cocontained compared to NGM. ELISA quantified penicillin, streptomycin, vitamin D, and insulin residues as risk factors in CCM. In conclusion, we utilized edible porous microcarriers to scale-up the expansion of Carassius auratus skeletal muscle cells and bioassembled high-quality CCM of Carassius auratus for the first time, which represents a state-of-the-art protocol applicable to different fish species and even to other economic animals and provides a theoretical basis for scaling up cell-cultured meat production.

Robot-based 6D bioprinting for soft tissue biomedical applications

Within this interdisciplinary study, we demonstrate the applicability of a 6D printer for soft tissue engineering models. For this purpose, a special plant was constructed, combining the technical requirements for 6D printing with the biological necessities, especially for soft tissue. Therefore, a commercial 6D robot arm was combined with a sterilizable housing (including a high-efficiency particulate air (HEPA) filter and ultraviolet radiation (UVC) lamps) and a custom-made printhead and printbed. Both components allow cooling and heating, which is desirable for working with viable cells. In addition, a spraying unit was installed that allows the distribution of fine droplets of a liquid. Advanced geometries on uneven or angled surfaces can be created with the use of all six axes. Based on often used bioinks in the field of soft tissue engineering (gellan gum, collagen, and gelatin methacryloyl) with very different material properties, we could demonstrate the flexibility of the printing system. Furthermore, cell-containing constructs using primary human adipose-derived stem cells (ASCs) could be produced in an automated manner. In addition to cell survival, the ability to differentiate along the adipogenic lineage could also be demonstrated as a representative of soft tissue engineering.

A 3D-printable gelatin/alginate/ε-poly-l-lysine hydrogel scaffold to enable porcine muscle stem cells expansion and differentiation for cultured meat development

The mass proliferation of seed cells and imitation of meat structures remain challenging for cell-cultured meat production. With excellent biocompatibility, high water content and porosity, hydrogels are frequently-studied materials for anchorage-dependent cell scaffolds in biotechnology applications. Herein, a scaffold based on gelatin/alginate/ε-Poly-l-lysine (GAL) hydrogel is developed for skeletal muscle cells, which has a great prospect in cell-cultured meat production. In this work, the hydrogel GAL-4:1, composed of gelatin (5 %, w/v), alginate (5 %, w/v) and ε-Poly-l-lysine (molar ratio vs. alginate: 4:1) is selected as cell scaffold based on Young's modulus of 11.29 ± 1.94 kPa, satisfactory shear-thinning property and suitable porous organized structure. The commercially available C2C12 mouse skeletal myoblasts and porcine muscle stem cells (PMuSCs), are cultured in the 3D-printed scaffold. The cells show strong ability of attachment, proliferation and differentiation after induction, showing high biocompatibility. Furthermore, the cellular bioprinting is performed with GAL-4:1 hydrogel and freshly extracted PMuSCs. The extracted PMuSCs exhibit high viability and display early myogenesis (desmin) on the 3D scaffold, suggesting the great potential of GAL hydrogel as 3D cellular constructs scaffolds. Overall, we develop a novel GAL hydrogel as a 3D-printed bioactive platform for cultured meat research.

Cellular memory function from 3D to 2D: Three-dimensional high density collagen microfiber cultures induce their resistance to reactive oxygen species

Cell properties generally change when the culture condition is changed. However, mesenchymal stem cells cultured on a hard material surface maintain their differentiation characteristics even after being cultured on a soft material surface. This phenomenon suggests the possibility of a cell culture material to memorize stem cell function even in changing cell culture conditions. However, there are no reports about cell memory function in three-dimensional (3D) culture. In this study, colon cancer cells were cultured with collagen microfibers (CMF) in 3D to evaluate their resistance to reactive oxygen species (ROS) in comparison with a monolayer (2D) culture condition and to understand the effect of 3D-culture on cell memory function. The ratio of ROS-negative cancer cells in 3D culture increased with increasing amounts of CMF and the highest amount of CMF was revealed to be 35-fold higher than that of the 2D condition. The ROS-negative cells ratio was maintained for 7 days after re-seeding in a 2D culture condition, suggesting a 3D-memory function of ROS resistance. The findings of this study will open up new opportunities for 3D culture to induce cell memory function.

Scalable Processes for Culturing Meat Using Edible Scaffolds

There is increasing consumer demand for alternative animal protein products that are delicious and sustainably produced to address concerns about the impacts of mass-produced meat on human and planetary health. Cultured meat has the potential to provide a source of nutritious dietary protein that both is palatable and has reduced environmental impact. However, strategies to support the production of cultured meats at the scale required for food consumption will be critical. In this review, we discuss the current challenges and opportunities of using edible scaffolds for scaling up the production of cultured meat. We provide an overview of different types of edible scaffolds, scaffold fabrication techniques, and common scaffold materials. Finally, we highlight potential advantages of using edible scaffolds to advance cultured meat production by accelerating cell growth and differentiation, providing structure to build complex 3D tissues, and enhancing the nutritional and sensory properties of cultured meat.

Space-Efficient 3D Microalgae Farming with Optimized Resource Utilization for Regenerative Food

Photosynthetic microalgae produce valuable metabolites and are a source of sustainable food that supports life without compromising arable land. However, the light self-shading, excessive water supply, and insufficient space utilization in microalgae farming have limited its potential in the inland areas most in need of regenerative food solutions. Herein, this work develops a 3D polysaccharide-based hydrogel scaffold for vertically farming microalgae without needing liquid media. This liquid-free strategy is compatible with diverse microalgal species and enables the design of living microalgal frameworks with customizable architectures that enhance light and water utilization. This approach significantly increases microalgae yield per unit water consumption, with an 8.8-fold increase compared to traditional methods. Furthermore, the dehydrated hydrogels demonstrate a reduced size and weight (≈70% reduction), but readily recover their vitality upon rehydration. Importantly, valuable natural products can be produced in this system including proteins, carbohydrates, lipids, and carotenoids. This study streamlines microalgae regenerative farming for low-carbon biomanufacturing by minimizing light self-shading, relieving water supply, and reducing physical footprints, and democratizing access to efficient aquatic food production.

Alternative protein sources: science powered startups to fuel food innovation

Harnessing the potential of considerable food security efforts requires the ability to translate them into commercial applications. This is particularly true for alternative protein sources and startups being on the forefront of innovation represent the latest advancements in this field.

Biofabrication's Contribution to the Evolution of Cultured Meat

Cultured Meat (CM) is a growing field in cellular agriculture, driven by the environmental impact of conventional meat production, which contributes to climate change and occupies ≈70% of arable land. As demand for meat alternatives rises, research in this area expands. CM production relies on tissue engineering techniques, where a limited number of animal cells are cultured in vitro and processed to create meat-like tissue comprising muscle and adipose components. Currently, CM is primarily produced on a small scale in pilot facilities. Producing a large cell mass based on suitable cell sources and bioreactors remains challenging. Advanced manufacturing methods and innovative materials are required to subsequently process this cell mass into CM products on a large scale. Consequently, CM is closely linked with biofabrication, a suite of technologies for precisely arranging cellular aggregates and cell-material composites to construct specific structures, often using robotics. This review provides insights into contemporary biomedical biofabrication technologies, focusing on significant advancements in muscle and adipose tissue biofabrication for CM production. Novel materials for biofabricating CM are also discussed, emphasizing their edibility and incorporation of healthful components. Finally, initial studies on biofabricated CM are examined, addressing current limitations and future challenges for large-scale production.

Nanostarch-Stimulated Cell Adhesion in 3D Bioprinted Hydrogel Scaffolds for Cell Cultured Meat

Three-dimensional (3D) bioprinting has great potential in the applications of tissue engineering, including cell culturing meat, because of its versatility and bioimitability. However, existing bio-inks used as edible scaffold materials lack high biocompatibility and mechanical strength to enable cell growth inside. Here, we added starch nanoparticles (SNPs) in a gelatin/sodium alginate (Gel/SA) hydrogel to enhance printing and supporting properties and created a microenvironment for adherent proliferation of piscine satellite cells (PSCs). We demonstrated the biocompatibility of SNPs for cells, with increasing 20.8% cell viability and 36.1% adhesion rate after 5 days of incubation. Transcriptomics analysis showed the mechanisms underlying the effects of SNPs on the adherent behavior of myoblasts. The 1% SNP group had a low gel point and viscosity for shaping with PSCs infusion and had a high cell number and myotube fusion index after cultivation. Furthermore, the formation of 3D muscle tissue with thicker myofibers was shown in the SNP-Gel/SA hydrogel by immunological staining.

Self-organization of vascularized skeletal muscle from bovine embryonic stem cells

Cultured beef holds promising potential as an alternative to traditional meat options. While adult stem cells are commonly used as the cell source for cultured beef, their proliferation and differentiation capacities are limited. To produce cultured beef steaks, current manufacturing plans often require the separate preparation of multiple cell types and intricate engineering for assembling them into structured tissues. In this study, we propose and report the co-induction of skeletal muscle, neuronal, and endothelial cells from bovine embryonic stem cells (ESCs) and the self-organization of tissue structures in 2- and 3-dimensional cultures. Bovine myocytes were induced in a stepwise manner through the induction of presomitic mesoderm (PSM) from bovine ESCs. Muscle fibers with sarcomeres appeared within 15 days, displaying calcium oscillations responsive to inputs from co-induced bovine spinal neurons. Bovine endothelial cells were also co-induced via PSM, forming uniform vessel networks inside tissues. Our serum-free, rapid co-induction protocols represent a milestone toward self-organizing beef steaks with integrated vasculature and innervation.

Stretchable zein-coated alginate fiber for aligning muscle cells to artificially produce cultivated meat

Numerous studies have explored the cultivation of muscle cells using non-animal materials for cultivated meat production. Achieving muscle cell proliferation and alignment using 3D scaffolds made from plant-based materials remains challenging. This study introduces a technique to culture and align muscle cells using only plant-based materials, avoiding toxic chemical modifications. Zein-alginate fibers (ZA fibers) were fabricated by coating zein protein onto alginate fibers (A fibers). Zein's excellent cell compatibility and biodegradability enable high cell adhesion and proliferation rates, and the good ductility of the ZA fibers enable a high strain rate (>75%). We demonstrate mature and aligned myotube formation in ZA fibers, providing a simple way to align muscle cells using plant-based materials. Additionally, cultivated meat was constructed by assembling muscle, fat, and vessel fibers. This method holds promise for the future mass production of cultivated meat.

Advances and Challenges in Cell Biology for Cultured Meat

Cultured meat is an emerging biotechnology that aims to produce meat from animal cell culture, rather than from the raising and slaughtering of livestock, on environmental and animal welfare grounds. The detailed understanding and accurate manipulation of cell biology are critical to the design of cultured meat bioprocesses. Recent years have seen significant interest in this field, with numerous scientific and commercial breakthroughs. Nevertheless, these technologies remain at a nascent stage, and myriad challenges remain, spanning the entire bioprocess. From a cell biological perspective, these include the identification of suitable starting cell types, tuning of proliferation and differentiation conditions, and optimization of cell-biomaterial interactions to create nutritious, enticing foods. Here, we discuss the key advances and outstanding challenges in cultured meat, with a particular focus on cell biology, and argue that solving the remaining bottlenecks in a cost-effective, scalable fashion will require coordinated, concerted scientific efforts. Success will also require solutions to nonscientific challenges, including regulatory approval, consumer acceptance, and market feasibility. However, if these can be overcome, cultured meat technologies can revolutionize our approach to food.

The microparticulate inks for bioprinting applications

Three-dimensional (3D) bioprinting has emerged as a groundbreaking technology for fabricating intricate and functional tissue constructs. Central to this technology are the bioinks, which provide structural support and mimic the extracellular environment, which is crucial for cellular executive function. This review summarizes the latest developments in microparticulate inks for 3D bioprinting and presents their inherent challenges. We categorize micro-particulate materials, including polymeric microparticles, tissue-derived microparticles, and bioactive inorganic microparticles, and introduce the microparticle ink formulations, including granular microparticles inks consisting of densely packed microparticles and composite microparticle inks comprising microparticles and interstitial matrix. The formulations of these microparticle inks are also delved into highlighting their capabilities as modular entities in 3D bioprinting. Finally, existing challenges and prospective research trajectories for advancing the design of microparticle inks for bioprinting are discussed.

Quality Control of Stem Cell-Based Cultured Meat According to Specific Differentiation Abilities

The demand for stem cell-based cultured meat as an alternative protein source is increasing in response to global food scarcity. However, the definition of quality controls, including appropriate growth factors and cell characteristics, remains incomplete. Cluster of differentiation (CD) 29 is ubiquitously expressed in bovine muscle tissue and is a marker of progenitor cells in cultured meat. However, CD29+ cells are naturally heterogeneous, and this quality control issue must be resolved. In this study, the aim was to identify the subpopulation of the CD29+ cell population with potential utility in cultured meat production. The CD29+ cell population exhibited heterogeneity, discernible through the CD44 and CD344 markers. CD29+CD44-CD344- cells displayed the ability for long-term culture, demonstrating high adipogenic potential and substantial lipid droplet accumulation, even within 3D cultures. Conversely, CD29+CD44+ cells exhibited rapid proliferation but were not viable for prolonged culture. Using cells suitable for adipocyte and muscle differentiation, we successfully designed meat buds, especially those rich in fat. Collectively, the identification and comprehension of distinct cell populations within bovine tissues contribute to quality control predictions in meat production. They also aid in establishing a stable and reliable cultured meat production technique.

Random cellulose acetate nanofibers: a breakthrough for cultivated meat production

Overcoming the challenge of creating thick, tissue-resembling muscle constructs is paramount in the field of cultivated meat production. This study investigates the remarkable potential of random cellulose acetate nanofibers (CAN) as a transformative scaffold for muscle tissue engineering (MTE), specifically in the context of cultivated meat applications. Through a comparative analysis between random and aligned CAN, utilizing C2C12 and H9c2 myoblasts, we unveil the unparalleled capabilities of random CAN in facilitating muscle differentiation, independent of differentiation media, by exploiting the YAP/TAZ-related mechanotransduction pathway. In addition, we have successfully developed a novel process for stacking cell-loaded CAN sheets, enabling the production of a three-dimensional meat product. C2C12 and H9c2 loaded CAN sheets were stacked (up to four layers) to form a ~300-400 μm thick tissue 2 cm in length, organized in a mesh of uniaxial aligned cells. To further demonstrate the effectiveness of this methodology for cultivated meat purposes, we have generated thick and viable constructs using chicken muscle satellite cells (cSCs) and random CAN. This groundbreaking discovery offers a cost-effective and biomimetic solution for cultivating and differentiating muscle cells, forging a crucial link between tissue engineering and the pursuit of sustainable and affordable cultivated meat production.

Cultured meat with enriched organoleptic properties by regulating cell differentiation

Research on cultured meat has primarily focused on the mass proliferation or differentiation of muscle cells; thus, the food characteristics of cultured meat remain relatively underexplored. As the quality of meat is determined by its organoleptic properties, cultured meat with similar sensory characteristics to animal-derived meat is highly desirable. In this study, we control the organoleptic and nutritional properties of cultured meat by tailoring the 2D differentiation of primary bovine myoblasts and primary bovine adipose-derived mesenchymal stem cells on gelatin/alginate scaffolds with varying stiffness. We assess the effect of muscle and adipose differentiation quality on the sensory properties of cultured meat. Thereafter, we fabricate cultured meat with similar sensory profiles to that of conventional beef by assembling the muscle and adipose constructs composed of highly differentiated cells. We introduce a strategy to produce cultured meat with enriched food characteristics by regulating cell differentiation with scaffold engineering.