Search Results (335)

Cultured meat is emerging as a sustainable alternative to conventional animal agriculture, with scaffolds playing a central role in supporting cellular attachment, growth, and tissue maturation. This review focuses on the development of gel-based hybrid biomaterials that meet the dual requirements of biocompatibility and food safety. We explore recent advances in the use of naturally derived gel-forming polymers such as gelatin, chitosan, cellulose, alginate, and plant-based proteins as the structural backbone for edible scaffolds. Particular attention is given to the integration of food-grade functional additives into hydrogel-based scaffolds. These include nanocellulose, dietary fibers, modified starches, polyphenols, and enzymatic crosslinkers such as transglutaminase, which enhance mechanical stability, rheological properties, and cell-guidance capabilities. Rather than focusing on fabrication methods or individual case studies, this review emphasizes the material-centric design strategies for building scalable, printable, and digestible gel scaffolds suitable for cultured meat production. By systemically evaluating the role of each component in structural reinforcement and biological interaction, this work provides a comprehensive frame work for designing next-generation edible scaffold systems. Nonetheless, the field continues to face challenges, including structural optimization, regulatory validation, and scale-up, which are critical for future implementation. Ultimately, hybrid gel-based scaffolds are positioned as a foundational technology for advancing the functionality, manufacturability, and consumer readiness of cultured meat products, distinguishing this work from previous reviews. Unlike previous reviews that have focused primarily on fabrication techniques or tissue engineering applications, this review provides a uniquely food-centric perspective by systematically evaluating the compositional design of hybrid hydrogel-based scaffolds with edibility, scalability, and consumer acceptance in mind. Through a comparative analysis of food-safe additives and naturally derived biopolymers, this review establishes a framework that bridges biomaterials science and food engineering to advance the practical realization of cultured meat products. Full article

Organoids and microphysiological systems (MPSs) have emerged as physiologically relevant platforms that recapitulate key structural and functional features of human organs, tissues, and microenvironments. As one of the essential components that define the success of these systems, hydrogels play the central role of providing a three-dimensional, biomimetic scaffold that supports cell viability, spatial organization, and dynamic signaling. Natural polymer-based hydrogels, derived from materials such as collagen, gelatin, hyaluronic acid, and alginate, offer favorable properties including biocompatibility, degradability, and an extracellular matrix-like architecture. This review presents recent advances in the design and application of such hydrogels, focusing on crosslinking strategies (physical, chemical, and hybrid), the viscoelastic characteristics, and stimuli-responsive behaviors. The influence of these materials on cellular processes, such as stemness maintenance, differentiation, and morphogenesis, is critically examined. Furthermore, the applications of organoid culture and dynamic MPS platforms are discussed, highlighting their roles in morphogen delivery, barrier formation, and vascularization. Current challenges and future perspectives toward achieving standardized, scalable, and translational hydrogel systems are also addressed. Full article

Hydrogel is widely used as a scaffolding material for tissue engineering due to its excellent cytocompatibility and potential for biofunctionalization. However, its poor mechanical property limits its further application. Fabrication of fiber-reinforced hydrogel composite scaffolds has emerged as a solution to overcome this problem. However, existing strategies usually produce nonporous composite scaffolds, where the interfiber pores are completely filled with hydrogel. This design can hinder oxygen and nutrient exchange between seeded cells and the culture medium, thereby limiting cell invasion and colonization within the scaffold. In this study, sodium alginate (SA) hydrogel was exclusively grafted onto the surface of the constituent fibers of the melt electrowritten scaffold while preserving the porous structure. The grafted hydrogel amount and pore size were precisely controlled by adjusting the SA concentration and the crosslinking ratio (SA: CaCl₂). Experimental results demonstrated that the porous composite scaffolds exhibited superior swelling capacity, degradation ratio, mechanical properties, and biocompatibility. Notably, at an SA concentration of 0.5% and a crosslinking ratio of 2:1, the porous composite scaffold achieved optimal cell adhesion and viability. This study highlights the critical importance of preserving porous structures in composite scaffolds for tissue-engineering applications. Full article

The application of cellular spheroids in bone tissue engineering research has gained significant interest in the last decade. Compared to monolayer cell cultures, the 3D architecture allows for more physiological cell–cell and cell–extracellular matrix (ECM) interactions that make cellular spheroids a suitable model system to investigate the bone ECM in vitro. The use of 3D model systems requires fine-tuning of the experimental methods used to study cell morphology, ECM deposition and mineralization, and cell–ECM interactions. In this study, we use a construct made of MC3T3-E1 cellular spheroids encapsulated in an alginate hydrogel to study and characterize the deposited ECM. Spheroid shape and structure were evaluated using confocal microscopy. The deposited collagenous ECM was characterized using Second Harmonic Imaging Microscopy (SHIM), quantitative hydroxyproline (HYP) assay, and Transmission Electron Microscopy (TEM). The use of hydrogel constructs enabled easy handling and imaging of the samples, while also helping to preserve the spheroid’s stability by preventing cells from adhering to the culture dish surface. We used a non-modified alginate hydrogel that did not facilitate cell attachment and therefore functioned as an inert encapsulating scaffold. Constructs were cultured for up to 4 weeks. SHIM, HYP assay, and TEM confirmed the deposition of a collagenous matrix. We demonstrated that alginate-encapsulated bone spheroids are a convenient and promising model for studying the bone ECM in vitro. Full article

The cryopreservation of three-dimensional (3D) biofabricated constructs is a key enabler for their clinical application in regenerative medicine. Unlike two-dimensional (2D) cultures, 3D systems such as encapsulated cell spheroids, molded hydrogels, and bioprinted tissues present specific challenges related to cryoprotectant (CPA) diffusion, thermal gradients, and ice formation during freezing and thawing. This review examines the current strategies for preserving 3D constructs, focusing on the role of biomaterials as cryoprotective matrices. Natural polymers (e.g., hyaluronic acid, alginate, chitosan), protein-based scaffolds (e.g., silk fibroin, sericin), and synthetic polymers (e.g., polyethylene glycol (PEG), polyvinyl alcohol (PVA)) are evaluated for their ability to support cell viability, structural integrity, and CPA transport. Special attention is given to cryoprotectant systems that are free of dimethyl sulfoxide (DMSO), and to the influence of hydrogel architecture on freezing outcomes. We have compared the efficacy and limitations of slow freezing and vitrification protocols and review innovative approaches such as temperature-controlled cryoprinting, nano-warming, and hybrid scaffolds with improved cryocompatibility. Additionally, we address the regulatory and manufacturing challenges associated with developing Good Manufacturing Practice (GMP)-compliant cryopreservation workflows. Overall, this review provides an integrated perspective on material-based strategies for 3D cryopreservation and identifies future directions to enable the long-term storage and clinical translation of engineered tissues. Full article

Plasma-derived fibrin hydrogels are widely used in tissue engineering because of their excellent biological properties. Specifically, human plasma-derived fibrin hydrogels serve as 3D matrices for autologous skin graft production, skeletal muscle repair, and bone regeneration. Nevertheless, for advanced applications such as in vitro skin equivalents and engineered grafts, the intrinsic limitations of native fibrin hydrogels in terms of long-term mechanical stability and resistance to degradation need to be addressed to enhance the usefulness and application of these hydrogels in tissue engineering. In this study, we chemically modified plasma-derived fibrin by incorporating succinimidyl alginate (SA), a version of alginate chemically modified to introduce reactive succinimidyl groups. These NHS ester groups (N-hydroxysuccinimide esters), attached to the alginate backbone, are highly reactive toward the primary amine groups present in plasma proteins such as fibrinogen. When mixed with plasma, the NHS groups covalently bond to the amine groups in fibrin, forming stable amide linkages that reinforce the fibrin network during hydrogel formation. This chemical modification improved mechanical properties, reduces contraction, and enhanced the stability of the resulting hydrogels. Hydrogels were prepared with a final fibrinogen concentration of 1.2 mg/mL and SA concentrations of 0.5, 1, 2, and 3 mg/mL. The objective was to evaluate whether this modification could create a more stable matrix suitable for supporting skin tissue development. The mechanical and microstructure properties of these new hydrogels were evaluated, as were their biocompatibility and potential to create 3D skin models in vitro. Dermo-epidermal skin cultures with primary human fibroblast and keratinocyte cells on these matrices showed improved dermal stability and better tissue structure, particularly SA concentrations of 0.5 and 1 mg/mL, as confirmed by H&E (Hematoxylin and Eosin) staining and immunostaining assays. Overall, these results suggest that SA-functionalized fibrin hydrogels are promising candidates for creating more stable in vitro skin models and engineered skin grafts, as well as for other types of engineered tissues, potentially. Full article

Stem cells cultured in cell aggregates exhibit higher cell survival rates and enhanced anti-inflammatory and angiogenic effects compared to single cells, constructing a stable and economical cell aggregate culture system that can accurately adjust the mass transfer distance of nutrients, which contributes to improving the therapeutic effects of stem cell aggregates. In this study, an alginate hydrogel microsphere culture system (Alg-HM) was prepared using electrostatic spraying technology and refined by optimizing the electrostatic spraying technology parameters, such as the sodium alginate concentration, voltage, electrospray injection speed, and nozzle inner diameter. Furthermore, by setting the Tip-dropped culture system (Tip-D culture system, created by dropping the resuspended hMSC aggregate–hydrogel solution with a tip to form the hydrogel microsphere) and Matrigel culture system (created by dropping the resuspended hMSC aggregates–Matrigel solution with a tip to form the Matrigel culture system) as the control group and Alg-HM as the experimental group, the culture effect of hMSC aggregates in the optimized Alg-HM culture system was tested; CCK-8 detection and Ki-67 immunofluorescence staining showed that the Alg-HM culture system significantly enhanced the cell proliferation activity of hMSC aggregates after 7 and 14 days of culture. The Calcein-AM/PI cell staining results showed that the Alg-HM culture system can significantly reduce the central necrosis of hMSC aggregates. The RNA sequencing results showed that the Alg-HM culture system can significantly activate the signaling pathways related to cell proliferation in hMSCs. This culture system is helpful for the culture of cell aggregates in vitro and efficient transplantation in vivo. Full article

In the last years, considerable innovation has been made regarding bioprinting, particularly in the development of cell-loaded hydrogels. The specific properties of the bioinks are crucial for printing an adequate cell-laden hydrogel structure. In this research, we aimed to develop a 3D-printable hydrogel using a natural biocompatible polymer. The process is based on the use of sodium alginate subjected to calcium ion cross-linking for immediate stiffness after printing. Using the Cellink INKREDIBLE+ printer (Cellink Inc., Goteborg, Sweden), 3D structures were successfully produced. The developed bioink exhibited a viscosity suitable for extrusion printing while ensuring its structural integrity at the same time. Next, 3D spheroids developed by using bioinks were morphologically characterized by using light, a fluorescent microscope, and field emission scanning electron microscopy (FESEM). In conclusion, the properties of the construct obtained using the lab-formulated biocompatible polymer hydrogel suggest its potential use as a framework for three-dimensional cell culture, with possible applications in both fields of research and regenerative medicine. Full article

Viral lung infections are a never-ending threat to public health due to the emergence of new variants and their seasonal nature. While vaccines offer some protection, the need for effective antiviral drugs remains high. The existing research methods using 2D cell culture and animal models have their limitations. Human cell-based tissue engineering approaches hold great promise for bridging this gap. Here, we describe a microextrusion bioprinting approach to generate three-dimensional (3D) lung models composed of four cell types: endothelial cells, primary fibroblasts, macrophage cells, and epithelial cells. A549 and Calu-3 cells were selected as epithelial cells to simulate the cells of the lower and upper respiratory tract, respectively. Cells were bioprinted in a hydrogel consisting of alginate, gelatin, hyaluronic acid, collagen, and laminin-521. The models were cultured under air–liquid interface (ALI) conditions to further enhance their physiological relevance as lung cells. Their viability, metabolic activity, and expression of specific cell markers were analyzed during long-term culture for 21 days. The constructs were successfully infected with both a seasonal influenza A virus (IAV) and the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) omicron variant, demonstrating their potential for studying diverse viral infections. Full article

Breast cancer remains the most common malignancy in women, yet, many patients fail to achieve full remission despite significant advancements. This is largely due to tumour heterogeneity and the limitations of current experimental models in accurately replicating the complexity of in vivo tumour environment. In this study, we present a compartmentalised alginate hydrogel platform as an innovative in vitro tool for three-dimensional breast cancer cell culture. To mimic the heterogeneity of tumour tissues, we developed a core–shell structure (3.5% alginate core and 2% alginate shell) that mimic the stiffer, denser internal tumour matrix. The human triple-negative breast cancer cell line (MDA-MB-231) was embedded in core–shell alginate gels to assess viability, proliferation and hypoxic activity. Over one week, good cells proliferation and viability was observed, especially in the softer shell. Interestingly, cells within the stiffer core were more positive to hypoxic marker expression (HIF-1α) than those embedded in the shell, confirming the presence of a hypoxic niche, as observed in vivo. When cultured in the MIVO^® milli fluidic organ-on-chip resembling the physiological fluid flow conditions, cancer cells viability became comparable between core and shell hydrogel area, emphasising the importance of the fluid flow in nutrients diffusion within three-dimensional matrixes. Cisplatin chemotherapy treatment further highlighted these differences: under static conditions, cancer cell death was prominent in the softer shell, whereas cells in the stiffer core remained resistant to cisplatin. Conversely, drug diffusion was more homogeneous in the core–shell structured treated in the organ-on-chip, leading to a uniform reduction in cell viability. These findings suggest that integrating a compartmentalised core–shell cell laden alginate model with the millifluidic organ on chip offers a more physiologically relevant experimental approach to deepening cancer cell behaviour and drug response. Full article

Hydrogels are one of the most attractive biomaterials, used in both three-dimensional (3D) and in vivo cultures. They facilitate the reconstruction of tissue microenvironments by preserving the spatial arrangement of cells, cell–cell interactions, and functional dynamics in the tissue. In this work, the long-term effect of alginate hydrogel on cell culture and the possibility of rapid cell recovery by dissolving the hydrogel were investigated. Mouse glial-restricted progenitors (GRPs) and porcine mesenchymal stem cells (MSCs) were suspended in hydrogels; their metabolic activity, viability, and expression of genes, which are involved in oxidative stress, apoptosis, proliferation, migration, and differentiation, were assessed using quantitative polymerase chain reaction (qPCR). The concentration that was able to dissolve the hydrogel and was the least harmful to the cells was 0.005 M ethylenediaminetetraacetic acid (EDTA). The metabolism of both cell types was reduced from the beginning of the experiment to day 3. From day 7 to the end of the experiment, the normalization of the GRP metabolism was observed, in contrast to the MSCs. For the apoptosis-related genes, caspase 3, 7, and B-cell leukemia (Casp3, Casp 7, Bcl2) were increased in GRPs and MSCs on days 0 and 1. After 3 and 7 days, an increase in the expression of oxidative stress genes (nuclear factor of activated T-cells 5—NFAT5 and autophagy-related 14-ATG14) was observed in cells cultured in calcium chloride (CaCl₂). GRPs cultured in calcium alginate (CaM) were not affected and, remarkably, showed increased Antigen Kiel 67 (Ki67) levels after 30 days. In conclusion, alginate hydrogels provide an excellent environment for stem cell culture in 3D for a longer period of time, but this is dependent on the cell type. Therefore, an individual approach to cell culture is necessary, taking into account the requirements of the cells to be used. Full article

Bone tissue engineering (BTE) emerged as a practical approach to tackle prosthetic industry limitations. We merge aspects from developmental biology, engineering and medicine with the aim to produce fully functional bone tissue. Mesenchymal stem cells have the capability of self-renewal and specific lineage differentiation. Herein lies their potential for BTE. Among MSCs, human dental pulp stem cells have a higher proliferation rate, shorter doubling times, lower cellular senescence, and enhanced osteogenesis than hBM-SCs under specific conditions. In addition, these cells are readily accessible and can be extracted through a subtle extraction procedure. Thus, they garner fewer moral concerns than most MSCs available and embody a promising cell source for BTE therapies able to replace hBM-MSCs. Interestingly, their study has been limited. Conversely, there is a need for their further study to harness their true value in BTE, with special emphasis in the design of bioprocesses able to produce viable, homogenous bone constructs in a clinical scale. Here, we study the osteogenic differentiation of hDPSCs encapsulated in alginate hydrogels under suspended culture in a novel perfusion bioreactor. The system is compared with traditional 3D static and fed-batch culture methodologies. The novel system performed better, producing higher alkaline phosphatase activity, and more homogeneous, dense and functional bone constructs. Additionally, cell constructs produced by the in-house-designed system were richer in mature osteoblast-like and mineralizing osteocyte-like cells. In conclusion, this study reports the development of a novel bioprocess able to produce hDPSC-based bone-like constructs, providing new insights into hDPSCs’ therapeutic potential and a system able to be transferred from the laboratory bench into medical facilities. Full article

This study aimed to evaluate the effect of the incorporation of silver nanoparticles (AgNPs) of 5.57 nm size into dental alginates on their deformation and antimicrobial properties. Six experimental groups were prepared: 2 different alginates with 0.25 wt% AgNPs, 2 different alginates with 0.5 wt% AgNPs (5.57 nm), and 2 unmodified control alginate groups. The presence of AgNPs was confirmed using X-ray diffraction analysis with a Bruker D8 Advance diffractometer. Antimicrobial activity was evaluated using the Kirby-Bauer disk diffusion method (direct contact) against E. coli and S. aureus cultures incubated on Mueller–Hinton (M-H) agar at 37 °C for 24 h. The results demonstrated that the addition of 0.25% and 0.5% AgNPs significantly enhanced the antimicrobial properties of alginate (p < 0.05), showing clear inhibition zones against the tested microorganisms. In terms of mechanical properties, AgNPs-modified samples exhibited improved elastic recovery compared to the control group (p > 0.05). These findings suggest that incorporating silver nanoparticles into alginates could enhance their antimicrobial properties without compromising the mechanical integrity required for dental applications. Full article

Synthetic seed technology is an innovative in vitro technique that provides improved storage capabilities for vegetative propagules. Its success mostly depends on the encapsulation matrix’s composition and the encapsulation procedure. The present study focuses on optimizing an encapsulation protocol for short-term storage and germplasm exchange using micro-cuttings of Salix tetrasperma. Among the different synthetic seed types evaluated, double-layered synthetic seeds (DLSs) exhibited the highest re-growth (93.6%) on MS medium supplemented with meta-Topolin (mT) (5.0 µM) and α-naphthalene acetic acid (NAA) (0.5 µM) after 8 weeks of culture. Viability assessment of non-embryogenic synthetic seeds during low-temperature storage (4 °C) demonstrated the enhanced resilience of double-layered synthetic seeds (DLSs) compared to their single-layered (SLS) counterparts. Following acclimatization in Soilrite^®-filled cups, 82% of the plantlets were successfully established in a greenhouse after four weeks. The increased activity and concentration of antioxidants in DLS-derived plantlets suggest the potential role of the extra layer of alginate in mitigating the effects of low-temperature stress during storage. SCoT molecular analysis confirmed the genetic integrity of the synthetic seed-derived plants. Full article

In this study, we aimed to develop soy protein-derived edible porous hydrogel scaffolds for cultured meat based on mechanical anisotropy to mimic the physical and biochemical properties of muscle tissues. Based on the traditional Japanese Ito-Kanten (thread agar) freeze–thaw process, we used liquid nitrogen directional freezing combined with ion crosslinking to fabricate an aligned scaffold composed of soy protein isolate (SPI), carrageenan (CA), and sodium alginate (SA). SPI, CA, and SA were dissolved in water, heated, mixed, and subjected to directional freezing in liquid nitrogen. The frozen gel was immersed in Ca²⁺ and K⁺ solutions for low-temperature crosslinking, followed by a second freezing step and lyophilization to create the SPI/CA/SA cryogel scaffold with anisotropic pore structure. Furthermore, C2C12 myoblasts were seeded onto the scaffold. After 14 d of dynamic culture, the cells exhibited significant differentiation along the aligned structure of the scaffold. Overall, our developed anisotropic scaffold provided a biocompatible environment to promote directed cell differentiation, showing potential for cultured meat production and serving as a sustainable protein source. Full article