Bioprocessing technology of muscle stem cells: implications for cultured meat

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.

The challenges of using fish cells for cultivated seafood production

Continuing population growth is increasing nutritional demand and applying pressure to the world's finite resources. The current food systems struggle with sustainability, especially regarding protein sources. To address this, organisations have invested in developing novel sources of protein, such as lab-grown cultivated foods. Most of these efforts have focussed on the cultivated meat industry but neglect the emerging cultivated seafood industry. Arguably, seafood has a greater impact on protein availability and sustainability and should be a priority. Nonetheless, several technical barriers exist to produce cultivated seafood, and include a lack of established cell lines and specialised cell growth medium, that is affordable and sustainable. In addition, the application of this technology is difficult, due to public perception, ethical considerations, taste and food safety hurdles. Herein, we review the barriers that must be overcome by research institutions, companies, and stakeholders so that products can be introduced to the mainstream consumer market.

Scalable production of muscle and adipose cell-laden microtissues using edible macroporous microcarriers for 3D printing of cultured fish fillets

Cellular agriculture is a novel platform for addressing the issues of protein scarcity, environmental pressures, and food safety. However, expanding seed cells at a large scale remains a prerequisite for achieving industrial cultured meat production. We here propose the production of large-pore-sized edible porous microcarriers (EPMs) by using NaCl to precisely control ice crystal growth during cryogenic crosslinking. Muscle satellite cells (SCs) and adipose-derived stem cells (ASCs) from large yellow croakers exhibit remarkable adhesion, proliferation, and differentiation on gelatin-based EPMs. Following consecutive expansion, SCs and ASCs densities reach 6.25 × 105 and 5.77 × 105 cells/mL, leading to a 499-fold and 461-fold increase in cell numbers, respectively. Subsequently, the mature microtissues are incorporated into a bioink, thereby enabling successful three-dimensional printing of cultured fish fillets with sensory properties similar to native fish fillets. EPM-based cell expansion and food structuring techniques are promising in facilitating large-scale cultured fish meat production.

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.

Can cell-cultured meat from stem cells pave the way for sustainable alternative protein?

As the global population grows, the demand for food and animal-derived products rises significantly, posing a notable challenge to the progress of society in general. Alternative protein production may adequately address such a challenge, and cell-based meat production emerges as a promising solution. This review investigates methodologies for in vitro myogenesis and adipogenesis from stem cells (adult, embryonic, or induced pluripotent stem cells - iPSCs) across different animal species, as well as the remaining challenges for scalability, the possibility of genetic modification, along with safety concerns regarding the commercialization of cell-cultured meat. Regarding such complexities, interdisciplinary approaches will be vital for assessing the potential of cell-cultured meat as a sustainable protein source, mimicking the sensory and nutritional attributes of conventional livestock meat whilst meeting the demands of a growing global population while mitigating environmental impacts.

Drone pupae extract enhances Hanwoo myosatellite cell function for cultivated meat production

In this study, we analyzed effects of drone pupae aqueous extract powder (DEP) on proliferation and differentiation of Hanwoo myosatellite cells (HSC). Results of amino acid, vitamin, and mineral analysis of drone pupae revealed the presence of branched-chain amino acids, Glu, essential amino acids, vitamins B6, C and Mg, K, and so on. Additionally, drone pupae were shown to have an antioxidant ability. HSC were cultured for proliferation by adding 0, 10, 100, 200, and 400 μg/mL DEP to the medium. As a result of MTS analysis, DEP increased the proliferation capacity of HSC, with cell viability being significantly higher after treatment with DEP, especially when DEP was used at 100 μg/mL (p < 0.05). To measure the differentiation ability of HSC, 0 and 100 μg/mL DEP (CON, D100) were added to the medium, and cells were cultured. Myotube formation was confirmed through images using immunofluorescence staining. Fusion index and myotube area in the D100 were higher than those in the CON (p < 0.01). DEP promoted differentiation ability and myotube formation by increasing the expression of MYH2, MYOG, and DES genes and MYH2 and DES proteins in HSC. Additionally, in HSC differentiation culture, proteome expression intensity was higher in D100 than in CON. Proteins upregulated in the D100 group included Myosin, IL18, MYO1D, and so on. In conclusion, characteristics of various components present in DEP could improve the proliferation and differentiation ability of HSC. This suggests that drone pupae can be used as a functional substance to enhance muscle growth.

Cell-Based Meat Safety and Regulatory Approaches: A Comprehensive Review

Cell-based meat (CBM) technology is a highly promising alternative to traditional animal agriculture, with considerable advantages in terms of sustainability, animal welfare, and food security. Nonetheless, CBM's successful commercialization is dependent on efficiently dealing with several critical concerns, including ensuring biological, chemical, and nutritional safety as well as navigating the global regulatory framework. To ensure CBM's biological safety, detecting and mitigating any potential hazards introduced during the manufacturing process is crucial. Concerns include microbial contamination, the utilization of animal-derived growth media, and the risk of viral or prion infection. Similarly, chemical hazards include residues from growth media, scaffolding materials, and other bioprocessing agents. For consumer acceptance, CBM's nutritional qualities should be comparable to those of conventional meat, indicating adequate protein content, essential amino acids, vitamins, and minerals. Additionally, CBM's safety in terms of allergenicity and the presence of anti-nutritional factors must be rigorously assessed. Advances in cell culture techniques and biomanufacturing methods are requisite to achieving high-quality CBM with desirable nutritional attributes. The regulatory framework for CBM is actively expanding, with significant regional variations. Singapore is currently the only country that has received approval for the market placement of CBM, although the United States has developed a regulatory structure involving the United States Department of Agriculture and Food and Drug Administration. As CBM holds great potential as a sustainable and ethical alternative to conventional meat, addressing challenges related to biological and chemical safety, nutritional quality, and regulatory approval is essential for its successful market integration.

The important role of cellular mechanical microenvironment in engineering structured cultivated meat: Recent advances

Cultivated meat (CM) provides a potential solution to meet the rising demand for eco-friendly meat supply systems. Recent efforts focus on producing CM that replicates the architecture and textural toughness of natural skeletal muscle. Significance of the regulated role of cellular microenvironment in myogenesis has been reinforced by the substantial influence of mechanical cues in mediating the muscle tissue organization. However, the formation of structured CM has not been adequately described in context of the mechanical microenvironment. In this review, we provide an updated understanding of the myogenesis process within mechanically dynamic three-dimensional microenvironments, discuss the effects of environmental mechanical factors on muscle tissue regeneration and how cell mechanics respond to the mechanical condition, and further highlight the role of mechanical cues as important references in constructing a sustainable Hydrocolloids-based biomaterials for CM engineering. These findings help to overcome current limitations in improving the textural properties of CM.

Recent advances in scaffolding biomaterials for cultivated meat

The emergence of cultivated meat provides a sustainable and ethical alternative to traditional animal agriculture, highlighting its increasing importance in the food industry. Biomaterial scaffolds are critical components in cultivated meat production for enabling cell adhesion, proliferation, differentiation, and orientation. While there's extensive research on scaffolding biomaterials, applying them to cultivated meat production poses distinct challenges, with each material offering its own set of advantages and disadvantages. This review summarizes the most recent scaffolding biomaterials used in the last five years for cell-cultured meat, detailing their respective advantages and disadvantages. We suggest future research directions and provide recommendations for scaffolds that support scalable, cost-effective, and safe high-quality meat production. Additionally, we highlight commercial challenges cultivated meat faces, encompassing bioreactor design, cell culture mediums, and regulatory and food safety issues. In summary, this review provides a comprehensive guide and valuable insights for researchers and companies in the field of cultivated meat production.

Genipin Activates Autophagy and Promotes Myoblast Differentiation by Activating AMPK Pathway

Cultured meat technology is expected to solve problems such as resource shortages and environmental pollution, but the muscle fiber differentiation efficiency of cultured meat is low. Genipin is the active compound derived from Gardenia jasminoides Ellis, which has a variety of activities. Additionally, genipin serves as a noncytotoxic agent for cross-linking, which is suitable as a foundational scaffold for in vitro tissue regeneration. However, the impact of genipin on myoblast differentiation remains to be studied. The research revealed that genipin was found to improve the differentiation efficiency of myoblasts. Genipin improved mitochondrial membrane potential by activating the AMPK signaling pathway of myoblasts, promoting mitochondrial biogenesis, and mitochondrial network remodeling. Genipin activated autophagy in myoblasts and maintained cellular homeostasis. Autophagy inhibitors blocked the pro-differentiation effect of genipin. These results showed that genipin improved the differentiation efficiency of myoblasts, which provided a theoretical basis for the development of cultured meat technology.

A comprehensive review on novel synthetic foods: Potential risk factors, detection strategies, and processing technologies

Nowadays, the food industry is facing challenges due to the simultaneous rise in global warming, population, and food consumption. As the integration of synthetic biology and food science, novel synthetic foods have obtained high attention to address these issues. However, these novel foods may cause potential risks related to human health. Four types of novel synthetic foods, including plant-based foods, cultured meat, fermented foods, and microalgae-based foods, were reviewed in the study. The original food sources, consumer acceptance, advantages and disadvantages of these foods were discussed. Furthermore, potential risk factors, such as nutritional, biological, and chemical risk factors, associated with these foods were described and analyzed. Additionally, the current detection methods (e.g., enzyme-linked immunosorbent assay, biosensors, chromatography, polymerase chain reaction, isothermal amplification, and microfluidic technology) and processing technologies (e.g., microwave treatment, ohmic heating, steam explosion, high hydrostatic pressure, ultrasound, cold plasma, and supercritical carbon dioxide) were reviewed and discussed critically. Nonetheless, it is crucial to continue innovating and developing new detection and processing technologies to effectively evaluate these novel synthetic foods and ensure their safety. Finally, approaches to enhance the quality of these foods were briefly presented. It will provide insights into the development and management of novel synthetic foods for food industry.

High-throughput analysis of hazards in novel food based on the density functional theory and multimodal deep learning

The emergence of cultured meat presents the potential for personalized food additive manufacturing, offering a solution to address future food resource scarcity. Processing raw materials and products in synthetic food products poses challenges in identifying hazards, impacting the entire industrial chain during the industry's further evolution. It is crucial to examine the correlation of biological information at different levels and to reveal the temporal dynamics jointly. Proposed active prevention method includes four aspects: (i) Investigating the molecular-level mechanism underlying the binding and dissociation of hazards with proteins represents a novel approach to mitigate matrix effect. (ii) Identifying distinct fragments is a pivotal advancement toward developing a novel screening strategy for hazards throughout the food chain. (iii) Designing an artificial intelligence model-based approach to acquire multi-dimensional histology data also holds significant potential for various applications. (iv) Integrating multimodal data is a practical approach to enhance evaluation and feedback control accuracy.

Considerations for cultivated crustacean meat: potential cell sources, potential differentiation and immortalization strategies, and lessons from crustacean and other animal models

Cultivated crustacean meat (CCM) is a means to create highly valued shrimp, lobster, and crab products directly from stem cells, thus removing the need to farm or fish live animals. Conventional crustacean enterprises face increasing pressures in managing overfishing, pollution, and the warming climate, so CCM may provide a way to ensure sufficient supply as global demand for these products grows. To support the development of CCM, this review briefly details crustacean cell culture work to date, before addressing what is presently known about crustacean muscle development, particularly the molecular mechanisms involved, and how this might relate to recent work on cultivated meat production in vertebrate species. Recognizing the current lack of cell lines available to establish CCM cultures, we also consider primary stem cell sources that can be obtained non-lethally including tissues from limbs which are readily released and regrown, and putative stem cells in circulating hemolymph. Molecular approaches to inducing myogenic differentiation and immortalization of putative stem cells are also reviewed. Finally, we assess the current status of tools available to CCM researchers, particularly antibodies, and propose avenues to address existing shortfalls in order to see the field progress.

Industrial Research and Development on the Production Process and Quality of Cultured Meat Hold Significant Value: A Review

Cultured meat has been gaining popularity as a solution to the increasing problem of food insecurity. Although research on cultured meat started later compared to other alternative meats, the industry is growing rapidly every year, with developed products evaluated as being most similar to conventional meat. Studies on cultured meat production techniques, such as culturing new animal cells and developing medium sera and scaffolds, are being conducted intensively and diversely. However, active in-depth research on the quality characteristics of cultured meat, including studies on the sensory and storage properties that directly influence consumer preferences, is still lacking. Additionally, studies on the combination or ratio of fat cells to muscle cells and on the improvement of microbiota, protein degradation, and fatty acid degradation remain to be conducted. By actively investigating these research topics, we aim to verify the quality and safety of cultured meats, ultimately improving the consumer preference for cultured meat products.

Cultured meat in the European Union: Legislative context and food safety issues

The current food system, which is responsible for about one third of all global gas emissions, is considered one of the main causes of resource depletion. For this reason, scientific research is investigating new alternatives capable of feeding an ever-growing population that is set to reach 9-11 billion by 2050. Among these, cell-based meat, also called cultured meat, is one possible solution. It is part of a larger branch of science called cellular agriculture, whose goal is to produce food from individual cells rather than whole organisms, tracing their molecular profile. To date, however, cultured meat aroused conflicting opinions. For this reason, the aim of this review was to take an in-depth look at the current European legislative framework, which reflects a 'precautionary approach' based on the assumption that these innovative foods require careful risk assessment to safeguard consumer health. In this context, the assessment of possible risks made it possible not only to identify the main critical points during each stage of the production chain (proliferation, differentiation, scaffolding, maturation and marketing), but also to identify solutions in accordance with the recommendations of the European Food Safety Authority (EFSA). Further, the main challenges related to organoleptic and nutritional properties have been reviewed.. Finally, possible future markets were studied, which would complement that of traditional meat, implementing the offer for the consumer, who is still sceptical about the acceptance of this new product. Although further investigation is needed, the growing demand for market diversification and the food security opportunities associated with food shortages, as well as justifying the commercialisation of cultured meat, would present an opportunity to position cultured meat as beneficial.

Methods to Isolate Muscle Stem Cells for Cell-Based Cultured Meat Production: A Review

Cultured meat production relies on various cell types, including muscle stem cells (MuSCs), embryonic stem cell lines, induced pluripotent cell lines, and naturally immortalized cell lines. MuSCs possess superior muscle differentiation capabilities compared to the other three cell lines, making them key for cultured meat development. Therefore, to produce cultured meat using MuSCs, they must first be effectively separated from muscles. At present, the methods used to isolate MuSCs from muscles include (1) the pre-plating method, using the ability of cells to adhere differently, which is a biological characteristic of MuSCs; (2) the density gradient centrifugation method, using the intrinsic density difference of cells, which is a physical characteristic of MuSCs; and (3) fluorescence- and magnetic-activated cell sorting methods, using the surface marker protein on the cell surface of MuSCs, which is a molecular characteristic of MuSCs. Further efficient and valuable methods for separating MuSCs are expected to be required as the cell-based cultured meat industry develops. Thus, we take a closer look at the four methods currently in use and discuss future development directions in this review.

A review: analysis of technical challenges in cultured meat production and its commercialization

The cultured meat technology has developed rapidly in recent years, but there are still many technical challenges that hinder the large-scale production and commercialization of cultured meat. Firstly, it is necessary to lay the foundation for cultured meat production by obtaining seed cells and maintaining stable cell functions. Next, technologies such as bioreactors are used to expand the scale of cell culture, and three-dimensional culture technologies such as scaffold culture or 3D printing are used to construct the three-dimensional structure of cultured meat. At the same time, it can reduce production costs by developing serum-free medium suitable for cultured meat. Finally, the edible quality of cultured meat is improved by evaluating food safety and sensory flavor, and combining ethical and consumer acceptability issues. Therefore, this review fully demonstrates the current development status and existing technical challenges of the cultured meat production technology with regard to the key points described above, in order to provide research ideas for the industrial production of cultured meat.

Development of a serum-free medium for myoblasts long-term expansion and 3D culture for cell-based meat

Cell-based meat technology provides an effective method to meet the demand for meat, while also posing a huge challenge to the expansion of myoblasts. It is difficult to develop serum-free medium suitable for long-term culture and large-scale expansion of myoblasts, which causes limited understanding of myoblasts expansion. Therefore, this study used C2C12 myoblasts as model cells and developed a serum-free medium for large-scale expansion of myoblasts in vitro using the Plackett-Burman design. The serum-free medium can support short-term proliferation and long-term passage of C2C12 myoblasts, while maintaining myogenic differentiation potential well, which is comparable to those of growth medium containing 10% fetal bovine serum. Based on the C2C12 myoblasts microcarriers serum-free culture system established in this study, the actual expansion folds of myoblasts can reach 43.55 folds after 7 days. Moreover, cell-based meat chunks were preliminarily prepared using glutamine transaminase and edible pigments. The research results provide reference for serum-free culture and large-scale expansion of myoblasts in vitro, laying the foundation for cell-based meat production. PRACTICAL APPLICATION: This study developed a serum-free medium suitable for long-term passage of myoblasts and established a microcarrier serum-free culture system for myoblasts, which is expected to solve the problem of serum-free culture and large-scale expansion of myoblasts in cell culture meat production.

Tuning the efficacy of decellularized apple by coating with alginate/gelatin to behave as a bioscaffold for cultured meat production

Substantial efforts are underway to tackle the current challenges of sustainability and environmental impacts linked to orthodox animal agriculture. This had led to advancement in food innovation guiding the fabrication of edible scaffolds based cultured meat. This current research work aims to develop and validate a new approach in fabricating a 3D porous scaffold of decellularized apple coated with a polymer mixture of gelatin/alginate for cultivated meat production. The fabricated noncoated (A) and coated (CA) 3D scaffolds presented different ratios of pore sizes with the medium-sized pores (100-250 µm) being higher in the case of CA. The water absorption capacity of CA (∼64 %) was almost two folds compared to A (∼31 %) with delayed digestion in the presence of gastric simulated juice with or without pepsin. Both the scaffolds showed the capability to adhere and proliferate muscle satellite cells as single cell culture and muscle satellite along with NIH/3T3 fibroblast cells as co-culture. However, the CA scaffolds showed enhanced capability to adhere and proliferate the two cell lines on its surface compared to A. This work demonstrates an efficient way to fabricate decellularized plant scaffolds with high potential to be used in the production of cultured meat for the food industry.

Generation of three-dimensional meat-like tissue from stable pig epiblast stem cells

Cultured meat production has emerged as a breakthrough technology for the global food industry with the potential to reduce challenges associated with environmental sustainability, global public health, animal welfare, and competition for food between humans and animals. The muscle stem cell lines currently used for cultured meat cannot be passaged in vitro for extended periods of time. Here, we develop a directional differentiation system of porcine pre-gastrulation epiblast stem cells (pgEpiSCs) with stable cellular features and achieve serum-free myogenic differentiation of the pgEpiSCs. We show that the pgEpiSCs-derived skeletal muscle progenitor cells and skeletal muscle fibers have typical muscle cell characteristics and display skeletal muscle transcriptional features during myogenic differentiation. Importantly, we establish a three-dimensional differentiation system for shaping cultured tissue by screening plant-based edible scaffolds of non-animal origin, followed by the generation of pgEpiSCs-derived cultured meat. These advances provide a technical approach for the development of cultured meat.

Efficient expression of a cytokine combination in Saccharomyces cerevisiae for cultured meat production

Cultured meat technology is a novel and promising alternative strategy for meat production, and it provides an efficient, safe, and sustainable way to supply animal protein. Cytokines play an important role in promoting the rapid proliferation of cells, but the high cost and potential food safety concerns of commercial cytokines have hindered their application in large-scale cultured meat production. Herein, Saccharomyces cerevisiae C800 was used as a starting strain in which four cytokines were exogenously expressed simultaneously using the Cre-loxP system, including long-chain human insulin growth factor-1, platelet-derived growth factor-BB, basic fibroblast growth factor, and epidermal growth factor. Through promoter optimization, endogenous protease knockout, genomic co-expression, expression frame gene order optimization, and fermentation optimization, a recombinant strain CPK2B2 co-expressing four cytokines was obtained with a yield of 18.35 mg/L. After cell lysis and filter sterilization, the CPK2B2 lysate was directly added to the culture medium of porcine muscle satellite cells (MuSCs). CPK2B2 lysate promoted the growth of MuSCs and increased the proportion of G2/S cells and EdU⁺ cells significantly, indicating its efficacy in promoting cell proliferation. This study provides a simple and cost-saving strategy by using S. cerevisiae to produce a recombinant cytokine combination for cultured meat production.

Gellan gum-gelatin scaffolds with Ca2+ crosslinking for constructing a structured cell cultured meat model

As an emerging technology to obtain protein by culturing animal-derived cells in vitro, it is crucial to construct 3D edible scaffolds to prepare structured cell cultured meat products. In this study, a scaffold based on gellan gum (GG)-gelatin (Gel) was prepared and further cross-linked with Ca2+. FTIR confirmed the electrostatic interaction between GG and Gel and the ionic cross-linking of Ca2+ and carboxyl groups, and SEM images showed the porous structure of the scaffolds. The staining results showed that scaffolds with high concentrations of Ca2+ had higher biocompatibility than scaffolds with low concentrations of Ca2+ and non-crosslinked scaffolds, and scaffolds Ca2+-GG2-Gel3-0.5 adhered to more cells and were more conducive to cell spreading. The immunofluorescence staining, SEM images, Western blot, and RT-qPCR showed that the scaffolds supported the proliferation and myogenic differentiation of chicken skeletal muscle satellite cells (CSMSCs) and myotubes were formed on the scaffolds. Finally, the scaffolds were stained and fried after culturing. The results of the textural and chromatic analysis showed that the texture and color of the scaffolds were similar to fresh meat and meat products. These results showed that ionically crosslinked GG-Gel scaffolds are biocompatible and stable for structured cell cultured meat models.

The Effect of Long-Term Passage on Porcine SMCs' Function and the Improvement of TGF-β1 on Porcine SMCs' Secretory Function in Late Passage

Cultured meat is one of the meat substitutes produced through tissue engineering and other technologies. Large-scale cell culture is the key for cultured meat products to enter the market. Therefore, this study is aimed to explore the effect of long-term passage in vitro on smooth muscle cells (SMCs) and the effect of transforming growth factor-β1 (TGF-β1) on SMCs in the late passage. Multiple passages lead to the decline of the proliferation rate of SMCs in the proliferation stage and the differentiation ability in the differentiation stage. Transcriptome results showed that the ECM pathway and aging-related signaling pathways were significantly up-regulated in the late passage period. TGF-β1 did not promote SMCs of late passage proliferation at the proliferation stage but promoted the gene and protein expression of collagen as the main protein of the extracellular matrix proteins at the differentiation stage. In addition, proteomic analysis revealed that TGF-β1 promoted the expression of cell adhesion molecules which activate the Hippo signaling pathway and the HIF-1 signaling pathway and further promoted the production of collagen-containing extracellular matrix proteins. This could provide ideas for large-scale production of cultured meat products using SMCs.

Bovine muscle satellite cells in calves and cattle: A comparative study of cellular and genetic characteristics for cultivated meat production

This study compared the cellular and genetic characteristics of bovine skeletal muscle satellite cells (SMSCs) from Hanwoo (a Korean native cattle breed), including calves and mature cattle. SMSCs were isolated using magnetic-activated cell sorting (MACS) from tissue samples of six Hanwoo (three calves and three mature cattle) using the CD29 antibody. Calves' SMSCs exhibited significantly faster growth rates than did those from cattle (P < 0.01), with a doubling time of 2.43 days. Genetic analysis revealed higher MyoD and Pax7 expression in SMSCs from calves during proliferation than in those from mature cattle (P < 0.001). However, FASN and PLAG1 expression levels were higher in mature cattle than in calves during both proliferation and differentiation (P < 0.001). These findings highlight the need for strategies to improve bovine muscle cell growth to produce competitive cultivated meat at a competitive price.

Static Magnetic Fields Promote Generation of Muscle Lineage Cells from Pluripotent Stem Cells and Myoblasts

Static magnetic fields (SMFs) exhibit numerous biological effects and regulate the proliferation and differentiation of several adult stem cells. However, the role of SMFs in the self-renewal maintenance and developmental potential of pluripotent embryonic stem cells (ESCs) remains largely uninvestigated. Here, we show that SMFs promote the expression of the core pluripotent markers Sox2 and SSEA-1. Furthermore, SMFs facilitate the differentiation of ESCs into cardiomyocytes and skeletal muscle cells. Consistently, transcriptome analysis reveals that muscle lineage differentiation and skeletal system specification of ESCs are remarkably strengthened by SMF stimuli. Additionally, when treated with SMFs, C2C12 myoblasts exhibit an increased proliferation rate, improved expression of skeletal muscle markers and elevated myogenic differentiation capacity compared with control cells. Together, our data show that SMFs effectively promote muscle cell generation from pluripotent stem cells and myoblasts. The noninvasive and convenient physical stimuli can be used to increase the production of muscle cells in regenerative medicine and the manufacture of cultured meat in cellular agriculture.

Repurposing biomedical muscle tissue engineering for cellular agriculture: challenges and opportunities

Cellular agriculture is an emerging field rooted in engineering meat-mimicking cell-laden structures using tissue engineering practices that have been developed for biomedical applications, including regenerative medicine. Research and industrial efforts are focused on reducing the cost and improving the throughput of cultivated meat (CM) production using these conventional practices. Due to key differences in the goals of muscle tissue engineering for biomedical versus food applications, conventional strategies may not be economically and technologically viable or socially acceptable. In this review, these two fields are critically compared, and the limitations of biomedical tissue engineering practices in achieving the important requirements of food production are discussed. Additionally, the possible solutions and the most promising biomanufacturing strategies for cellular agriculture are highlighted.

Production of mature myotubes in vitro improves the texture and protein quality of cultured pork

Cultured meat technology provides a promising strategy for the production of meat protein, which is an important nutrient in daily life. Currently, there is still a lack of systematic research on the basic determinants of the texture and protein quality of cultured meat. Here we first developed a chemically defined serum-free medium consisting of serum substitutes and the differentiation-promoting natural compound naringenin (NAR), which showed excellent efficacy in inducing differentiation of porcine satellite cells (PSCs) to generate mature myotubes in vitro. Then, cultured pork samples consisting of proliferating PSCs or differentiated myotubes were manufactured by culturing PSCs in different media with textured vegetable protein (TVP) scaffolds. By analyzing the appearance, texture, chemical composition, and amino acid ratio of these cultured pork samples, we found that the content and maturity of myotubes in cultured meat play an essential role in determining its quality as meat. These findings contribute to the commercial application and establishment of standards for cultured meat as a new protein food.

Big data and machine learning driven bioprocessing - Recent trends and critical analysis

Given the potential of machine learning algorithms in revolutionizing the bioengineering field, this paper examined and summarized the literature related to artificial intelligence (AI) in the bioprocessing field. Natural language processing (NLP) was employed to explore the direction of the research domain. All the papers from 2013 to 2022 with specific keywords of bioprocessing using AI were extracted from Scopus and grouped into two five-year periods of 2013-to-2017 and 2018-to-2022, where the past and recent research directions were compared. Based on this procedure, selected sample papers from recent five years were subjected to further review and analysis. The result shows that 50% of the publications in the past five-year focused on topics related to hybrid models, ANN, biopharmaceutical manufacturing, and biorefinery. The summarization and analysis of the outcome indicated that implementing AI could improve the design and process engineering strategies in bioprocessing fields.

Auxenochlorella pyrenoidosa extract supplementation replacing fetal bovine serum for Carassius auratus muscle cell culture under low-serum conditions

Cultured meat production requires large-scale cell proliferation in vitro with the supplementation of necessary media especially serum. This study investigated the capacity of Auxenochlorella pyrenoidosa extract (APE) to replace fetal bovine serum (FBS) for cell culture under low-serum conditions using Carassius auratus muscle (CAM) cells. Supplementation with APE and 5% FBS in the culture media significantly promoted the proliferation of CAM cells and increased the expression of MyoD in cells compared to that with 5% FBS through cell counting kit-8 and immunofluorescence staining assay. In addition, CAM cells in the media containing 5% FBS and APE could be continually cultured for 4 passages, and the cell number was 1.58 times higher than the counterpart without APE in long-term culture. Moreover, supplementation with APE realized large-scale culture on microcarriers under low-serum conditions, and more adherent cells were observed on microcarriers in 2% FBS supplemented with APE, compared with those in 2% FBS and 10% FBS without APE. These findings highlighted a potentially promising application of APE in muscle cell culture under low-serum conditions for cultured meat production.

Naringenin Promotes Myotube Formation and Maturation for Cultured Meat Production

Cultured meat is an emerging technology for manufacturing meat through cell culture rather than animal rearing. Under most existing culture systems, the content and maturity of in vitro generated myotubes are insufficient, limiting the application and public acceptance of cultured meat. Here we demonstrated that a natural compound, naringenin (NAR), promoted myogenic differentiation of porcine satellite cells (PSCs) in vitro and increased the content and maturity of generated myotubes, especially for PSCs that had undergone extensive expansion. Mechanistically, NAR upregulated the IGF-1/AKT/mTOR anabolic pathway during the myogenesis of PSCs by activating the estrogen receptor β. Moreover, PSCs were mixed with hydrogels and cultured in a mold with parallel micro-channels to manufacture cultured pork samples. More mature myosin was detected, and obvious sarcomere was observed when the differentiation medium was supplemented with NAR. Taken together, these findings suggested that NAR induced the differentiation of PSCs and generation of mature myotubes through upregulation of the IGF-1 signaling, contributing to the development of efficient and innovative cultured meat production systems.

Optimal Pre-Plating Method of Chicken Satellite Cells for Cultured Meat Production

To establish a pre-plating method of chicken satellite cells with high purity, pre-plating was performed under culture conditions of 37°C and 41°C, and the pre-plating time was set from a total of 3 hours to 6 hours in consideration of the cell attachment time. The purity of the cells was confirmed by staining paired box protein 7 (Pax7) after proliferation, and Pax7 expression was the highest in culture flasks shaken for 2 hours after incubation at 41°C for 2 hours to prevent the attachment of satellite cells (p<0.05). Also, when pre-plating and proliferation were performed at 37°C and 41°C, the Pax7 expression rate was higher at 41°C. The differentiation capabilities of the three groups (T3, T6, and T7) with high Pax7 expression were compared and the fusion index (%) and myotube formation area (%) determined by myosin heavy chain (MHC) staining was calculated. The T6 and T7 groups, which were cultured at 41°C, showed significantly higher values than the T3 group (p<0.05). There was no significant difference in the expression of Pax7 and MHC between the T6 and T7 groups (p>0.05). These results suggest that pre-plating at 41°C for a total of 4 hours was the most efficient in terms of cost and time for purifying chicken satellite cells for cultured meat.

Technological and structural aspects of scaffold manufacturing for cultured meat: recent advances, challenges, and opportunities

In vitro cultured meat is an emerging area of research focus with an innovative approach through tissue engineering (i.e., cellular engineering) to meet the global food demand. The manufacturing of lab-cultivated meat is an innovative business that alleviates life-threatening environmental issues concerning public health and animal well-being on the global platform. There has been a noteworthy advancement in cultivating artificial meat, but still, there are numerous challenges that impede the swift headway of lab-grown meat production at a commercially large scale. In this review, we focus on the manufacturing of edible scaffolds for cultured meat production. In brief, first an introduction to cultivating artificial meat and its current scenario in the market is provided. Further, a discussion on the understanding of composition, cellular, and molecular communications in muscle tissue is presented, which are vital to scaling up the production of lab-grown meat. In continuation, the major components (e.g., cells, biomaterial scaffolds, and their manufacturing technologies, media, and potential bioreactors) for cultured meat production are conferred followed by a comprehensive discussion on the most recent advances in lab-cultured meat. Finally, existing challenges and opportunities including future research perspectives for scaling-up cultured meat production are discussed with conclusive interpretations.

Alternative fat: redefining adipocytes for biomanufacturing cultivated meat

Cellular agriculture provides a potentially sustainable way of producing cultivated meat as an alternative protein source. In addition to muscle and connective tissue, fat is an important component of animal meat that contributes to taste, texture, tenderness, and nutritional profiles. However, while the biology of fat cells (adipocytes) is well studied, there is a lack of investigation on how adipocytes from agricultural species are isolated, produced, and incorporated as food constituents. Recently we compiled all protocols related to generation and analysis of adipose progenitors from bovine, porcine, chicken, other livestock and seafood species. In this review we summarize recent developments and present key scientific questions and challenges that need to be addressed in order to advance the biomanufacture of 'alternative fat'.

Using Vertebrate Stem and Progenitor Cells for Cellular Agriculture, State-of-the-Art, Challenges, and Future Perspectives

Global food systems are under significant pressure to provide enough food, particularly protein-rich foods whose demand is on the rise in times of crisis and inflation, as presently existing due to post-COVID-19 pandemic effects and ongoing conflict in Ukraine and resulting in looming food insecurity, according to FAO. Cultivated meat (CM) and cultivated seafood (CS) are protein-rich alternatives for traditional meat and fish that are obtained via cellular agriculture (CA) i.e., tissue engineering for food applications. Stem and progenitor cells are the building blocks and starting point for any CA bioprocess. This review presents CA-relevant vertebrate cell types and procedures needed for their myogenic and adipogenic differentiation since muscle and fat tissue are the primary target tissues for CM/CS production. The review also describes existing challenges, such as a need for immortalized cell lines, or physical and biochemical parameters needed for enhanced meat/fat culture efficiency and ways to address them.

Vitamin C enhances the ex vivo proliferation of porcine muscle stem cells for cultured meat production

Cultured meat technology is a promising alternative strategy for supplying animal protein taking advantage of its efficiency, safety, and sustainability. The muscle stem cell (MuSC) is one of the most important seed cells for producing muscle fibers, but its weak ex vivo proliferation capacity limits the industrialization of cultured meat. Here we reported that vitamin C (VC) is an excellent supplement for the long-term culture of porcine MuSCs (pMuSCs) ex vivo with considerable proliferative and myogenic effects. After 29 days of culture with 100 μM VC, pMuSCs achieved a 2.8 × 10⁷ ± 0.8 × 10⁷-fold increase in the total cell number, which was 360 times higher than that of cells without VC treatment. pMuSCs that were exposed to VC were less arrested in the G0/G1 phase and showed a significant increase in the expression of cell cycle-related genes such as Cdk1, Cdk2, and Ki67. Additionally, the differentiation potential of pMuSCs was enhanced when cells were proliferated with VC, as evidenced by increased expression of MyoD and MyHC. Furthermore, we demonstrated that VC exerted its proliferative effect through activating the PI3K/AKT/mTOR pathway via the IGF-1 signaling. These findings highlighted the potential application of VC in the ex vivo expansion of pMuSCs for cultured meat production.

IGF-1 Signaling Regulates Mitochondrial Remodeling during Myogenic Differentiation

Skeletal muscle is essential for locomotion, metabolism, and protein homeostasis in the body. Mitochondria have been considered as a key target to regulate metabolic switch during myo-genesis. The insulin-like growth factor 1 (IGF-1) signaling through the AKT/mammalian target of rapamycin (mTOR) pathway has a well-documented role in promoting muscle growth and regeneration, but whether it is involved in mitochondrial behavior and function remains un-examined. In this study, we investigated the effect of IGF-1 signaling on mitochondrial remodeling during myogenic differentiation. The results demonstrated that IGF-1 signaling stimulated mitochondrial biogenesis by increasing mitochondrial DNA copy number and expression of genes such as Cox7a1, Tfb1m, and Ppargc1a. Moreover, the level of mitophagy in differentiating myoblasts elevated significantly with IGF-1 treatment, which contributed to mitochondrial turnover. Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3) were identified as two key mediators of IGF-1-induced mitochondrial biogenesis and mitophagy, respectively. In addition, IGF-1 supplementation could alleviate impaired myoblast differentiation caused by mitophagy deficiency, as evidenced by increased fusion index and myosin heavy chain expression. These findings provide new insights into the role of IGF-1 signaling and suggest that IGF-1 signaling can serve as a target for the research and development of drugs and nutrients that support muscle growth and regeneration.