Engineered Protein Hydrogels as Biomimetic Cellular Scaffolds

From molecular mechanisms to clinical translation: Silk fibroin-based biomaterials for next-generation wound healing

Silk fibroin (SF) is a natural polymeric material that has attracted intense research attention in the field of wound healing due to its exceptional mechanical properties, tunable biodegradability, and multifunctional bioactivity. This review systematically summarizes the preparation strategies, functional modifications, and multidimensional application mechanisms of SF and its composite materials in wound healing. The innovative applications of SF in intelligent dressing design, immunometabolic regulation, controlled drug release, stem-cell function modulation, and bioelectrical-activity-mediated microenvironment remodeling is further explored, while analyzing the therapeutic efficacy and cost-effectiveness of SF through clinical translation cases. Distinct from previous reviews, this work not only integrates the latest advances in SF molecular mechanisms and material design but also emphasizes its potential in precision medicine, such as the development of genetically engineered SF for customized immunoregulatory networks. Finally, the article highlights the current challenges in the development of SF materials, including mechanical stability, degradation controllability, and standardization of large-scale production, and envisions future research directions driven by 3D bioprinting and synthetic biology technologies. This review provides a theoretical foundation and technical reference information for the development of efficient, multifunctional, and clinically translatable SF-based materials for application in wound healing.

Biomimetic Hydrogels from Mixed Gellan Gum and Tryptophan Zipper Self-Assembling Peptides

Peptide self-assembly has been used to fabricate synthetic hydrogels that emulate many of the chemical and physical properties of natural hydrogels. However, these materials often lack stability for many applications and do not display the native bioactivity found in tissue. Here we demonstrate a hybrid hydrogel system in which self-assembling peptides are integrated with polysaccharides to enhance gelation and provide improved mechanics and bioactivity. A peptide based on the tryptophan zipper (trpzip) motif was mixed with the anionic polysaccharide gellan gum, demonstrating gelation within minutes with increased stiffness compared to that of trpzip alone. The hybrid material maintained viscoelastic character with shear-thinning, self-healing, and stress-relaxation on the order of natural materials like collagen. All hydrogels supported cell adhesion and viability with increased gellan gum content, promoting cell assembly into aggregates. The enhanced gelation kinetics, stability, self-healing, and bioactivity of these materials make them promising candidates as matrices for cell culture and reagents for biofabrication and syringe extrusion for biological delivery.

Self-assembly of Tyrosine Scaffolds in Aqueous Media: Complex Molecular Architectures from Simple Building Blocks

Mimicking natural systems, self-assembly has been employed for constructing highly stable and well-ordered supramolecular structures. Amino acids are frequently used as building blocks in the self-assembly process due to their advantageous characteristics including easy availability, easy functionalization, tunable mechanical property, and biodegradability. In situ generation of active building blocks to obtain complex materials via self-assembly has enhanced their application in biomedical fields including bio-imaging, therapeutics. Single amino acid as the small building-block can provide artificial supramolecular materials with unique properties. In this review, we summarize the self-assembly of tyrosine-derivatives as single amino acid-based building blocks providing supramolecular assemblies and provide perspectives on their potential impact. Finally, we discuss the ongoing challenges for future research.

Innovative approaches to boost mesenchymal stem cells efficacy in myocardial infarction therapy

Stem cell-based therapy has emerged as a promising approach for heart repair, potentially regenerating damaged heart tissue and improving outcomes for patients with heart disease. However, the efficacy of stem cell-based therapies remains limited by several challenges, including poor cell survival, low retention rates, poor integration, and limited functional outcomes. This article reviews current enhancement strategies to optimize mesenchymal stem cell therapy for cardiac repair. Key approaches include optimizing cell delivery methods, enhancing cell engraftment, promoting cell functions through genetic and molecular modifications, enhancing the paracrine effects of stem cells, and leveraging biomaterials and tissue engineering techniques. By focusing on these enhancement techniques, the paper highlights innovative approaches that can potentially transform stem cell therapy into a more viable and effective treatment option for cardiac repair. The ongoing research and technological advancements continue to push the boundaries, hoping to make stem cell therapy a mainstream treatment for heart disease.

Pickering emulsions stabilized by soybean protein-based nanoparticles: A review of formulation, characterization, and food-grade applications

Pickering emulsions (PEs) have attracted considerable interest as platforms for encapsulating and controlling the release of bioactive compounds. Recent studies emphasize the potential of soybean protein nanoparticles to improve PE-based carriers, enhancing the stability and bioavailability of these compounds through unique self-assembly behaviors. This review analyzes recent advancements in the use of soybean protein nanoparticle-stabilized PEs as carriers for bioactive compounds. Various fabrication techniques, including physical, chemical, and biological methods, are explored. The effectiveness of soybean protein nanoparticles, both individually and in combination with polysaccharides or polyphenols, is evaluated, highlighting their roles in stabilizing PEs and enhancing functionality. Findings indicate that soybean protein nanoparticles are effective stabilizers for a wide range of PE structures, including oil-in-water, water-in-oil, high internal phase PEs, and Pickering emulgels. Fabrication methods, properties of Pickering particles, processing parameters, and formulations significantly influence the interfacial behavior, structure, and functionality of PEs. Fabrication methods, properties of Pickering particles, processing parameters, and formulations significantly influence the interfacial behavior, structure, and functionality of PEs. Additionally, innovative applications and future developments of soybean protein-based Pickering nanoparticles are discussed, emphasizing plant-based substitutes and advanced materials. Despite extensive discussions on soybean protein-based PEs in various food forms, research into their techno-functional properties and flavor mechanisms remains limited.

The HELP-UnaG Fusion Protein as a Bilirubin Biosensor: From Theory to Mature Technological Development

HUG is the HELP-UnaG recombinant fusion protein featuring the typical functions of both HELP and UnaG. In HUG, the HELP domain is a thermoresponsive human elastin-like polypeptide. It forms a shield enwrapping the UnaG domain that emits bilirubin-dependent fluorescence. Here, we recapitulate the technological development of this bifunctional synthetic protein from the theoretical background of its distinct protein moieties to the detailed characterization of its macromolecular and functional properties. These pieces of knowledge are the foundations for HUG production and application in the fluorometric analysis of bilirubin and its congeners, biliverdin and bilirubin glucuronide. These bile pigments are metabolites that arise from the catabolism of heme, the prosthetic group of cytochromes, hemoglobin and several other intracellular enzymes engaged in electron transfer, oxygen transport and protection against oxygen free radicals. The HUG assay is a powerful, user-friendly and affordable analytical tool that alone supports research at each level of complexity or taxonomy of living entities, from enzymology, cell biology and pathophysiology to veterinary and clinical sciences.

Order-Disorder Balance in Silk-Elastin-like Polypeptides Determines Their Self-Assembly into Hydrogel Networks

The biofabrication of recombinant structural proteins with a range of mechanical or structural features usually relies on the generation of protein libraries displaying variations in terms of amino acid composition, block structure, molecular weight, or physical/chemical cross-linking sites. This approach, while highly successful in generating a wealth of knowledge regarding the links between design features and material properties, has some inherent limitations related to its low throughput. This slows down the pace of the development of de novo recombinant structural proteins. Here, we propose an approach to tune the viscoelastic properties of temperature-responsive hydrogels made of silk-elastin-like polypeptides (SELPs) without modifying their sequence. To do so, we subject purified SELPs to two different postprocessing methods─water annealing or EtOH annealing─that alter the topology of highly disordered SELP networks via the formation of ordered intermolecular β-sheet physical cross-links. Combining different analytical techniques, we connect the order/disorder balance in SELPs with their gelling behavior. Furthermore, we show that introducing a functional block (in this case, a biomineralizing peptide) in the sequence of SELPs can disrupt its self-assembly and that such disruption can only be overcome by EtOH annealing. Our results suggest that postprocessing of as-purified SELPs might be a simple approach to tune the self-assembly of SELPs into biomaterials with bespoke viscoelastic properties beyond the traditional approach of developing SELP libraries via genetic engineering.