Search Results (355)

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

This study systematically evaluated the effects of pH (4–10) on the gelation properties, structural characteristics, and in vitro digestion–fermentation behavior of fish gelatin (FG, 6% (w/v)) hydrogels combined with either xanthan gum (XG, 0.07% (w/v)) or κ-carrageenan (κC, 0.07% (w/v)). The results revealed that the gel strength, hardness, and chewiness of the composite gels initially increased (pH 4–6) and subsequently decreased with rising pH levels. This trend correlated with the formation of a dense gel network structure. Furthermore, as pH increased, in vitro digestibility showed a similar pH-dependent trend, with FG–XG demonstrating superior enhancement compared to FG–κC. The addition of XG and κC resulted in increased gas production and a decreased pH during fermentation. Intestinal microbiota analysis revealed that both FG–XG and FG–κC improved the abundances of Proteobacteria and Bacteroidete while reducing Firmicutes. Compared to FG–XG and FG, FG–κC promoted higher levels of the genera Lachnospiraceae and Bacteroides, suggesting a more favorable impact on intestinal health. These findings provide valuable insights into the pH-responsive functional properties of FG-based hydrogels and their potential applications in designing novel food matrices with enhanced nutritional and probiotic attributes. Full article

Stimulus-responsive hydrogels have broad applications in the biomedical, sensing, and actuation fields. However, conventional fabrication methods are often limited to 2D structures, hindering the creation of complex, personalized 3D hydrogel architectures. Furthermore, hydrogels responding to only a single stimulus and delays in fabrication techniques restrict their practical utility in biomedicine. In this study, we developed two novel multi-stimuli-responsive hydrogels (based on Gelatin/Sodium Alginate and Tannic Acid/EDTA-FeNa complexes) specifically designed for direct ink writing (DIW) 3D printing. We systematically characterized the printed properties and optimized component ratio, revealing sufficient mechanical strength (e.g., tensile modulus: Gel/SA-TA ≥ 0.22854 ± 0.021 MPa and Gel/SA-TA@Fe³⁺ ≥ 0.35881 ± 0.021 MPa), high water content (e.g., water absorption rate Gel/SA-TA ≥ 70.21% ± 1.5% and Gel/SA-TA@Fe³⁺ ≥ 64.86% ± 1.28%), excellent biocompatibility (e.g., cell viability: Gel/SA-TA and Gel/SA-TA@Fe³⁺ ≥ 90%) and good shape memory performance (e.g., the highest shape recovery rate of Gel/SA-TA reaches 74.85% ± 4.776%). Furthermore, we explored electrical characteristics, showing that the impedance value of Gel/SA-TA@Fe³⁺ hydrogel changes significantly under finger bending and NIR irradiation. This investigation demonstrates the potential of these 3D-printed multi-stimuli hydrogels for applications such as wearable flexible strain sensors. Full article

Gelatin hydrogels for food packaging applications have aroused interest in recent years. However, these hydrogels exhibit several limitations, such as poor mechanical strength and low swelling and water uptake. To overcome these challenges, nanocellulose can be used as a nanofiller. Thus, cellulose nanofibrils (CNFs) were obtained from soybean straw and used as a nanofiller for hydrogels produced with type A and B gelatin. The effects of the biopolymer type and the influence of CNF concentrations (0–3.0%, w/w) on the properties of hydrogels were studied. The CNFs exhibited a fiber morphology with micrometer length and nanometer diameter (16.8 ± 1.2 nm). The addition of CNFs (0–3%, w/w) caused a decrease in the stress (~50%) and elongation (~14%) at the fracture of the hydrogels for both type of gelatin. However, the elastic modulus increased (~20%). The addition of CNFs increased the hardness of the hydrogels up to 25%. The swelling capacity decreased by ~30% when the CNF concentration increased from 0 to 3%, while the thermal properties and chemical structure were not altered. These findings provide valuable insights for ongoing research into the incorporation of nanocellulose in biopolymer-based hydrogels produced by physical and sustainable methods for food packaging applications. Full article

Spinal cord injuries (SCIs) present a major clinical challenge, often resulting in permanent loss of function and limited treatment options. Traditional approaches, including surgery, drugs, and rehabilitation, have had modest success in restoring neural connectivity due to the complex pathophysiology of SCI. In recent years, bioactive hydrogels have gained attention as a versatile platform for neural repair. Their ability to mimic the extracellular matrix, deliver therapeutic agents, and support cell survival makes them promising tools in regenerative medicine. This narrative review highlights the latest advances in hydrogel-based therapies for SCI, with a focus on innovations such as self-healing, conductive, and anti-inflammatory hydrogels. We also explore hybrid approaches that integrate nanomaterials, stem cells, and bioelectronics to address both primary and secondary injury mechanisms. While various hydrogel systems have been investigated, we place particular emphasis on gelatin-based hydrogels, especially gelatin methacryloyl (GelMA), due to their emerging clinical relevance. GelMA stands out for its bioactivity, tunable mechanics, and compatibility with 3D printing, making it a strong candidate for personalized therapies and scalable production. Unlike previous reviews that broadly summarize hydrogel use, this work specifically contextualizes gelatin-based platforms within the wider landscape of SCI repair, underscoring their translational potential. We also address current challenges, such as immune response, long-term integration, and clinical validation, and suggest future directions for bridging the gap from bench to bedside. Full article

Peripheral nerve injuries (PNIs) present a significant clinical challenge due to the inherently limited regenerative capacity of the adult nervous system. Conventional therapeutic strategies, such as nerve autografting and systemic pharmacological interventions, are often limited by donor site morbidity, restricted graft availability, and suboptimal drug bioavailability. In this context, gelatin-based hydrogels have emerged as a promising class of biomaterials due to their excellent biocompatibility, biodegradability, and structural similarity to the native extracellular matrix. These hydrogels could offer a highly tunable platform capable of supporting cellular adhesion, promoting axonal elongation, and enabling localized and sustained release of therapeutic agents. This narrative review synthesizes recent advances in the application of gelatin-based hydrogels for peripheral nerve regeneration, with a particular focus on their use as delivery vehicles for neurotrophic factors, stem cells, and pharmacologically active compounds. Additionally, this review provides a foundation for extending our ongoing preclinical study, evaluating the neuroregenerative effects of alpha-lipoic acid, B-complex vitamins, and a deproteinized hemoderivative in a murine PNI model. Although systemic administration has demonstrated promising neuroprotective effects, limitations related to local drug availability and off-target exposure highlight the need for site-specific delivery strategies. In this regard, gelatin hydrogels might represent an excellent candidate for localized, controlled drug delivery. The review concludes by discussing formulation techniques, manufacturing considerations, biological performance, and key translational and regulatory aspects. Full article

Gelatin is a commonly used protein-based hydrogel. However, the thermo-reversible nature of gelatin makes it unstable at physiological and higher temperatures. Therefore, this study adopted phosphates and glutaminase transaminase (TG) to modify gelation and studied the effects of combining sodium hexametaphosphate (SHP) and TG on the structure and gel properties of TG-crosslinked gelatin. This study focused on the effects of different SHP concentrations (0, 0.4, 0.8, 1.2, 1.6, 2.0, 2.4, 2.8 mmol/L) on the water distribution, textural properties, rheological properties, and microstructure of the TG-crosslinked gelatin gels. Results showed that the free water content in the TG-crosslinked gelatin gel declined with the increasing SHP addition when the concentration of SHP was kept below 2.0 mmol/L. The gel of TG-crosslinked gelatin at the SHP concentration of 1.6 mmol/L exhibited the highest hardness (304.258 g), chewiness (366.916 g) and η₅₀. All the TG-crosslinked gelatin gels with SHP modification were non-Newtonian pseudoplastic fluids. The G′ and G″ of TG-crosslinked gelatin increased before the SHP concentration reached 1.6 mmol/L, and the TG-crosslinked gelatin with 1.6 mmol/L SHP exhibited the largest G″ and G′. The fluorescence intensity of TG-crosslinked gelatin with SHP concentration above 1.6 mmol/L decreased with the increasing SHP concentration. SHP modified the secondary structure of TG-crosslinked gelatin gels. The gel of TG-crosslinked gelatin with the SHP concentration of 1.6 mmol/L exhibited a porous, smooth, and dense network structure. This research provides references for modifying gelatin and the application of gels in the encapsulation of bioactive ingredients and probiotics. Full article

Gelatin, a biocompatible and biodegradable polymer, has garnered considerable attention in tissue engineering (TE) due to its diverse applications enabled by its tunable physical properties. Among the various strategies employed for the fabrication of gelatin-based hydrogels, the use of horseradish peroxidase (HRP) and hydrogen peroxide (H₂O₂) as a catalytic system has been highlighted as an effective tool for producing hydrogels with highly modifiable properties. Herein, we explore recent progress in the utilization of the HRP/H₂O₂ catalytic system for the creation of gelatin-based hydrogels, with an emphasis on TE applications. Particular attention has been given to the interplay between variations in the concentration equilibrium of HRP and H₂O₂ and the fine-tuning of gel properties tailored for various TE applications. Emerging trends, such as in situ gelation and hybrid bioinks, have also been examined through the lens of their prospective applications, extrapolating from the findings in cell cultures and animal models. A comprehensive review of two databases (Scopus and Web of Science) was conducted. The data extracted from each study included the materials used for each application, methods used for material preparation, cells used in the TE application, laboratory animals used, and whether computational/simulation techniques were implemented. The applications included both homopolymeric hydrogels, using only gelatin as the backbone, and copolymeric hydrogels, with ≥2 polymers. Full article

The development of printable, biocompatible, biodegradable, and cost-effective bioinks, or biomaterial inks, remains a focal point in extrusion-based bioprinting research. In this study, fish gelatin (FG) was reinforced with microcrystalline cellulose (MCC) to formulate biomaterial inks. These FG/MCC composite inks were fabricated into 3D scaffolds using an extrusion bioprinter. The influence of MCC concentration on printability was systematically evaluated. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses confirmed the formation of hydrogen bonds between MCC and FG, indicating molecular-level interactions. Notably, MCC incorporation enhanced the rheological properties of the ink and significantly improved the compressive strength of printed scaffolds. Furthermore, MCC content modulated key scaffold characteristics, including porosity, degradation rate, swelling behavior, and microarchitecture. These findings demonstrate that FG/MCC composite hydrogels exhibit optimal properties for extrusion-based 3D bioprinting, offering a promising platform for tissue engineering applications. 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

Bioelectronics for wearable and implantable biomedical devices has attracted significant attention due to its potential for continuous health monitoring, early disease diagnosis, and real-time therapeutic interventions. Among the various materials explored for bioelectronic applications, hydrogels derived from natural biopolymers have emerged as highly promising candidates, owing to their inherent biocompatibility, mechanical compliance akin to biological tissues, and tunable structural properties. This review provides a comprehensive overview of recent advancements in the design and application of protein-based hydrogels, including gelatin, collagen, silk fibroin, and gluten, as well as carbohydrate-based hydrogels such as chitosan, cellulose, alginate, and starch. Particular emphasis is placed on elucidating their intrinsic material characteristics, modification strategies to improve electrical and mechanical performance, and their applicability for bioelectronic interfaces. The review further explores their diverse applications in physiological and biochemical signal sensing, bioelectric signal recording, and electrical stimulation. Finally, current challenges and future perspectives are discussed to guide the ongoing innovation of hydrogel-based systems for next-generation bioelectronic technologies. Full article

High and large-spectrum antibacterial features and ROS scavenging properties are the most important requirements for efficient wound-dressing materials. A composite hydrogel was synthesized herein by a one-pot procedure embedding silver nanoparticles (AgNPs) covered with oxidized gum arabic (OGA) within gelatin (Gel) hydrogel. Small (2–20 nm), round-shaped AgNPs (ζ = −22 mV) were first obtained by green synthesis using OGA as a reducing and capping agent. Composite hydrogels, containing 0.6 and 1.3 wt.% Ag, were obtained by the covalent cross-linking (Schiff base reaction) of amine groups in gelatin with the dialdehyde groups located on the shell of the AgNPs. Thus, the uniform distribution of the AgNPs in the network contributed to the increased physicochemical and hydrolytic stability of the hydrogels. Moreover, the high swelling degree together with the good mechanical properties make them appropriate candidates for wound-healing materials. The hydrogels exhibited 80% scavenging activity of ABTS^●+ free radicals after 6 h of incubation and were effective against E. coli and S. aureus, achieving a 4% survival of bacteria within 3 h (E. coli) and 24 h (S. aureus). These results clearly indicate that the proposed hydrogels have potential in wound-dressing applications. Full article

A platform of two-component cross-linked hydrogel (cGEL) based on gelatinous peptides and anhydride-containing cross-linkers (oPNMA, oPDMA) is extended for use in peripheral nerve regeneration. Hybrid composites with bio-/chemical cues for enhanced biophysical and biochemical properties were fabricated by covalently grafting small molecular, heterobifunctional amines including the nerve growth factor mimetic LM11A-31 to the oligomeric cross-linkers prior to hydrogel formation. The cytocompatibility and growth-supportive conditions within the matrix are confirmed for pristine and modified hydrogels using L929 mouse fibroblasts and human adipose-derived stem cells (hASCs). For hASCs, cell behavior depends on the type of cross-linker and integrated amine. In a subsequent step, neonatal rat Schwann cells (SCs) are seeded on pristine and functionalized cGEL to investigate the materials’ capabilities to support SC growth and morphology. Within all formulations, cell viability, adherence, and cell extension are maintained though the cell elongation and orientation vary compared to the two-dimensional control. It is possible to merge adjustable two-component hydrogels with amines as biochemical signals, leading to improved nervous cell proliferation and activity. This indicates the potential of tunable bioactive cGEL as biomaterials in nerve implants, suggesting their use as a foundational component for nerve conduits. Full article

Current hydrogels used for cartilage tissue engineering often lack the mechanical strength and structural integrity required to mimic native human cartilage. This study addresses this limitation by developing reinforced hydrogels based on a ternary polymer blend of poly(vinyl) alcohol (PVA), gelatin (GL), and chitosan (CH), with gentamicin sulfate (GS) as an antimicrobial agent and a crosslinker. The hydrogels were produced using two crosslinking methods, the freeze/thaw and heated cycles, and reinforced with forcespun polycaprolactone (PCL) nanofiber to improve mechanical performance. Chemical characterization revealed that GS forms weak hydrogen bonds with the ternary polymers, leading to esterification with PVA, and covalent bonds are formed as the result of the free amino group (-NH₂) of chitosan that reacts with the carboxylic acid group (-COOH) of gelatin. SEM images help us to see how the hydrogels are reinforced with polycaprolactone (PCL) fibers produced via force spinning technology, while mechanical properties were evaluated via uniaxial tensile and compressive tests. Water retention measurements were performed to examine the crosslinking process’s influence on the hydrogel’s water retention, while the hydrogel surface roughness was obtained via confocal microscopy images. A constitutive model based on non-Gaussian strain energy density was introduced to predict experimental mechanical behavior data of the hydrogel, considering a non-monotonous softening function. Loading and unloading tests demonstrated that GS enhanced crosslinking without compromising water retention or biocompatibility because of the reaction between the free amino group of CH and the carboxylic group of gelatin. The PCL-reinforced PVA/GL/CH hydrogel shows strong potential for cartilage repair and tissue engineering applications. Full article