Bioinspired conductive and antibacterial hydrogel bionanocomposite based on tragacanth gum, polyaniline and osteoconductive SiO2 nanoparticles as a scaffold for bone tissue engineering application.

Montmorillonite-reinforced methacrylated collagen/methacrylated silk fibroin hydrogel-based inks: rheological and physicochemical characterization for bone scaffold applications.

Collagen is widely used in bone tissue engineering due to its biocompatibility; however, its poor mechanical properties, limited print fidelity restrict its use in extrusion-based bioprinting. Collagen methacrylate (ColMA) improves structural stability via photopolymerization but remains prone to enzymatic degradation. In this study, methacrylated silk fibroin (SFMA) and montmorillonite clay (MMT) were incorporated into ColMA-based systems to enhance mechanical performance and mimic aspects of the bone extracellular matrix. Successful methacrylation of ColMA and SFMA was confirmed by 1H NMR and TNBS assay, while FTIR analysis indicated interactions between the polymeric network and the clay phase. Rheological characterization, before and after UV exposure, revealed increased viscosity and a transition to predominantly elastic behavior after photopolymerization, indicating effective network formation. Extrusion-based 3D printing of SFMA/ColMA +3.0% MMT enabled the fabrication of porous grid structures with good shape fidelity, followed by rapid curing under UV light (365 nm, 40 s). These results demonstrate that montmorillonite-reinforced ColMA/SFMA systems are promising hydrogel-based inks for bone scaffold applications.

Bioactive electrospun chitosan/magnesium-doped hydroxyapatite nanocomposite scaffold co-loaded with icariin, lithium chloride and naringin for enhanced osteogenesis, antibacterial activity and bone regeneration in vitro and in vivo

Bioinspired PEEK/Bioactive Glass/β-TCP Hybrid Composites With Nano-HA Coatings: Interfacial Apatite Nucleation, Wettability Tuning, and In Vitro Bioactivity for Load-Bearing Bone Repair

This study addresses the longstanding challenge of balancing mechanical performance and biological activity in load-bearing bone regeneration. A multifunctional composite was developed based on polyetheretherketone (PEEK) reinforced with bioactive glass fibers and β -tricalcium phosphate (β -TCP), followed by surface functionalization using nano-hydroxyapatite (nano-HA) coating. Structural and spectroscopic analyses confirmed preservation of the PEEK molecular backbone and stable incorporation of ceramic phases. At the same time, the nano-HA layer formed a biomimetic hierarchical interface resembling natural bone mineral. Quantitatively, the modified composite exhibited a marked improvement in surface wettability, with a contact angle of 29.83°, indicating excellent hydrophilicity relative to pristine PEEK. In simulated body fluid (SBF), rapid and sustained apatite formation was observed, confirming high in vitro bioactivity. Biological evaluation demonstrated controlled ion release behavior that effectively inhibited bacterial growth while maintaining mammalian cell viability. In addition, the composite exhibited a suitable density of about 1.22 g/cm3, which is close to the reference value of the density of the bone cement composites used in orthopedic applications. Additionally, a controlled coating thickness was about 58.32 micrometres supported structural stability and ensured effective and homogeneous surface coverage Overall, the developed PEEK/bioactive glass/β -TCP/nano-HA composite demonstrates strong potential for next-generation load-bearing implants, offering enhanced osseointegration, improved surface bioactivity, and balanced antibacterial performance while retaining favorable mechanical characteristics.

DLP 3D cell bioprinting of gelatin methacryloyl-tannic acid hydrogels as a tunable platform for bioactive skin tissue engineering scaffolds.

Although 3D cell bioprinting has emerged as a powerful strategy for engineering biomimetic skin substitutes and wound-related materials, the development of bioinks that simultaneously provide structural integrity, cytocompatibility, and bioactivity remains challenging. In this work, gelatin methacryloyl (GelMA)-based hydrogels incorporating tannic acid (TA) were developed and processed via digital light processing to fabricate 3D scaffolds as prototype platforms for skin-related applications. The incorporation of TA significantly enhanced hydrogel stability, mechanical stiffness, and antibacterial activity, while maintaining high water content and improving print fidelity. Structural characterization by SEM and micro-CT revealed that TA promoted the formation of a more compact and homogeneous porous network, consistent with increased storage modulus, improved compressive strength and delayed degradation under physiological conditions. Rheological analysis confirmed that GelMA+TA systems exhibit enhanced viscoelastic stability and resistance to deformation. Sustained TA release over 25 days endowed the scaffolds with antibacterial activity against E. coli and S. aureus. Importantly, 3D bioprinting and encapsulation studies demonstrated cell-type-dependent biological responses. Human skin fibroblasts exhibited robust long-term viability and proliferation within pure GelMA scaffolds, while TA-containing hydrogels promoted early cell-material interactions and fibronectin deposition but were associated with reduced long-term fibroblast proliferation, suggesting a dose- and exposure-dependent effect of TA. In contrast, Vero cells, used as a model epithelial cell line, showed improved viability and morphology under encapsulation conditions in GelMA+TA scaffolds. These results highlight the critical interplay between macromolecular composition, 3D microenvironment, and cell response, demonstrating that GelMA+TA systems represent a promising preliminary platform for the development of tunable bioactive scaffolds for wound-related applications.

Biomedical Hydrogel Bio-Adhesive Based on Lactobionic Acid Conjugated Polyethylenimine and Oxidized Dextran with Antioxidant Activity and Cytocompatibility

Background/Objectives: Tissue bio-adhesives have gained significant attention as efficient alternatives to conventional wound closures, which are often hindered by insufficient adhesion and poor biocompatibility. Methods: Inspired by nature’s robust wet-adhesion strategies that use dynamic covalent interactions, we have reported a facilely fabricated hydrogel bio-adhesive based on lactobionic acid-conjugated polyethylenimine (LA-PEI) and oxidized dextran (ODex) via Schiff base linkages. Results: The prepared hydrogels exhibited three-dimensional interconnected porous networks, regulated swelling ratios, typical viscoelasticity, shear-thinning behavior, and self-healing ability. Notably, the swelling ratios of the hydrogels depended on composition, and OLP11 displayed the highest swelling ratio of over 1500%. The hydrogel bio-adhesives exhibited strong adhesion to various surfaces, including glass, metal, plastic, rubber, and wood, as well as to different chicken organs, including the heart, liver, spleen, and stomach. Furthermore, the hydrogels exhibited excellent ABTS radical-scavenging activity, effective intracellular reactive oxygen species (ROS) scavenging, and good hemocompatibility, with hemolysis ratios of all hydrogels close to 0%, below the threshold of 5%. After culturing with NIH 3T3 fibroblasts, the hydrogels demonstrated good cytocompatibility and promoted cell proliferation, with cell viabilities on day 3 reaching over 90%. Conclusions: This design yields multifunctional hydrogel bio-adhesives, showing strong promise for wound care and tissue repair applications.

Composite Hydrogel Using Methacrylated Silk Fibroin and Mercaptolated Hyaluronic Acid with Encapsulating Zinc-Quercetin Nanozyme

Given the urgent need to regulate oxidative stress microenvironments in chronic wound healing, hydrogel dressings that simultaneously integrate antioxidant, antibacterial, mechanically adaptive, and biocompatible properties are highly desirable. In this study, a natural polymer-based composite hydrogel dressing loaded with zinc-quercetin nanozyme (Zn-Q) was designed. The gel skeleton was constructed via a dual network of photocrosslinked methacrylated silk fibroin (SilMA) and mercaptolated hyaluronic acid (HA-SH) via thiol-ene click chemistry, with the catalase (CAT)-like Zn-Q nanozyme encapsulated in situ within the network, thereby achieving synergy between chemical crosslinking and dynamic metal-polyphenol coordination. Systematic characterization revealed that Zn-Q nanozyme adopted a stable octahedral coordination configuration, and its continuous porous structure exposed abundant catalytically active sites. The composite hydrogels exhibited a highly interconnected, three-dimensional (3D) porous morphology, with swelling ratios that increased significantly with Zn-Q nanozyme content (up to around 1082%). Rheological and mechanical tests demonstrated that although incorporating the nanozyme reduced the storage modulus, the reversible physical crosslinks formed via hydrogen bonding and coordination interactions endowed the material with excellent tensile toughness and energy-dissipation capacity, exhibiting typical Mullins softening behavior. Functional evaluation showed that Zn-Q nanozyme conferred superior free radical scavenging capability to the hydrogels and exerted dose-dependent inhibition against both Staphylococcus aureus and Escherichia coli. Furthermore, the hydrogels exhibited favorable adhesion to various wet organs and heterogeneous material surfaces, with hemolysis rates below 5% and cell viability exceeding 100% after 3 days of culturing with fibroblasts, confirming their excellent hemocompatibility and cytocompatibility. This study provides an experimental basis for developing a new type of wound repair materials that integrate antioxidant, anti-infective, and mechanically adaptive properties, holding significant application potential in oxidative stress-related tissue repair fields.