Tissue repair is challenged by inefficient cellular infiltration and prolonged inflammation. Herein, the mesoporous polydopamine nanoparticles were loaded with spermidine and then encapsulated in agarose, which were incorporated into the oxidized hyaluronic acid crosslinked collagen matrix to fabricate NIR-activated hydrogel (DOCH@P) by the directional freeze-thaw process. DOCH@P hydrogel had obvious oriented microchannel structure due to the extrusion of directional ice crystals and the chemical crosslinking during the directional freeze-thaw process, besides enhanced mechanical properties, viscoelasticity and favorable tissue adhesive strength. DOCH@P hydrogel with photothermal performance promoted the melting of the agarose in the shell of nanoparticles under NIR-activation, thus achieving NIR-responsive spermidine release behavior. NIR-activated DOCH@P hydrogel exhibited significantly robust broad-spectrum antibacterial activity and antioxidative activity. Significantly, DOCH@P hydrogel demonstrated superior capabilities in inducing directional migration and infiltration of fibroblasts through the synergistic integration of the oriented microchannels physical contact guidance and spermidine bioactivity. Based on the multi-layered spermidine-mediated immunoregulation, NIR-activated DOCH@P hydrogel ultimately drove macrophages towards anti-inflammatory M2 phenotype to alleviate excessive inflammation and remold immune homeostasis. Overall, the NIR-activated collagen-based hydrogel with oriented microchannel structure provides a promising scaffold foundation for guiding tissue regeneration through physical contact-guided cellular infiltration and anti-inflammation.
Real-time, in situ monitoring of plant physiological parameters and industrial toxic gas emissions is vital for advancing precision agriculture and ensuring environmental safety. Herein, we developed an electroactive biodegradable microneedle (PPG-MN) sensor enabling minimally invasive monitoring of interstitial glucose, ambient temperature, humidity, and environmental ammonia (NH3) gas leakage. The sensor matrix was fabricated using a polyvinyl alcohol (PVA) network interpenetrated with conductive polyaniline (PANI) and doped with phytic acid (PA), while glucose oxidase (GOx) was immobilized for specificity. The resulting microneedle array exhibited sufficient mechanical strength to penetrate the plant epidermis, establishing a stable electrode–tissue interface via hydrogel swelling. The sensor demonstrated excellent environmental friendliness, featuring a pathogen inhibition rate exceeding 97
UV-induced skin photoaging is a complex pathology driven by oxidative stress and extracellular matrix (ECM) depletion. Although recombinant human collagen (RHC) and epigallocatechin-3-gallate (EGCG) address these mechanisms, their synergy is limited by RHC’ s poor permeability and EGCG’ s instability. Here, we present a supramolecular co-assembly strategy to overcome these barriers. Validated by molecular dynamics simulations, we utilized the intrinsic proline-rich domains of RHC as anchors for EGCG to construct uniform nanospheres (< 100 nm). This architecture sterically shields EGCG, significantly enhancing stability and reducing cytotoxicity. Biologically, the nanospheres restored mitochondrial membrane potential and promoted anti-inflammatory M2 macrophage polarization. In a photoaging mouse model, the nanospheres outperformed monotherapies, effectively reversing epidermal hyperplasia and restoring the Type I/III collagen ratio. This study resolves the delivery-stability paradox of protein–polyphenol therapeutics, offering a potent strategy for regenerating photodamaged skin.
Osteoarthritis (OA), a prevalent chronic degenerative joint disorder, affects hundreds of millions of people worldwide and has become a leading cause of joint pain and functional impairment in middle-aged and elderly populations. It not only severely compromises patients’ quality of life but also imposes a significant socioeconomic burden on public health systems. Targeting key pathological processes in OA, such as inflammatory responses, chondrocyte apoptosis, and dysregulated autophagy, an injectable liposomal system named RAPA@Lipo/rhCol Ⅲ were developed in this study. This system consisted of rapamycin-loaded liposomes surface-modified with recombinant human collagen type Ⅲ (rhCol Ⅲ). It enabled sustained release of rapamycin to precisely inhibit the mTOR pathway, thereby exerting synergistic biological effects including anti-inflammation, inhibition of chondrocyte apoptosis, and promotion of autophagy. Moreover, the surface collagen modification enhanced the system’s biocompatibility and provided essential matrix microenvironment cues and bioactive signals for cartilage repair. Experimental results demonstrated that RAPA@Lipo/rhCol Ⅲ effectively scavenged reactive oxygen species in chondrocytes, promoted cell proliferation and cartilage matrix synthesis, and modulated the expression of autophagy- and inflammation-related genes, thereby synergistically achieving structural and functional restoration of OA cartilage across multiple dimensions. The integrated “disease modulation-tissue repair” strategy proposed in this study offerd a novel approach and experimental evidence for targeted therapy and functional regeneration in osteoarthritis.
Emerging carbonized polymer dots (CPDs) from natural aromatic-like lignin biopolymer have ignited the renaissance of sustainable nanoscale biomass valorization but are hindered by structural instability and functionality barriers. Herein, we report an interfacial heterostructure engineering that immobilizes lignin-based dual-emissive CPDs onto Fe, Co layered double hydroxides (LDHs), with the function of a recyclable electrode. The CPDs deliver a stable metal-ion binding behavior via rapid light-quenching with a low limit-of-detection, which are fixed into FeCo-LDH to improve the electrical conductivity, available reactive site, structural stability, and charge storage. The reconstructed FeCo-LDH@CPDs electrode outputs an ultrahigh specific capacitance of 1842.0 F g− 1 at 1 A g− 1. When assembled into a symmetrical supercapacitor (SSCs), it also achieves a superior energy density of 33.79 Wh kg− 1 at 375 W kg− 1, excellent rate performance and long-term cycling lifespan (100
Meniscus possesses weak self-repairability once getting hurt due to heterogeneity, particularly “white region” of avascular parts. However, the effect of conventional therapies in restoring structure and function of the meniscus isn’t ideal. Collagen, a key part of the extracellular matrix, is quite promising. Its excellent biocompatibility and biological activity enable collagen-based tissue-engineered meniscus scaffolds to be safely implanted in the body, effectively improving the pathological and physiological state of cells at the meniscus injury site and the surrounding microenvironment. This review describes the application of different implantable medical collagen-based materials used for meniscal regeneration and repair. Firstly, the structure and physiological function of meniscus are described briefly. Then, different collagen-based materials for meniscal repair are introduced emphatically. Last but not least, some current challenges and issues regarding collagen-based strategies on meniscus repair are analyzed so as to provide strategies for future studies.
Biodegradability of finished leather is crucial for the sustainable development of the leather industry. Herein, the biodegradability evaluation system of finished leather was engineered using soil burial degradation, microbial community dynamics, and biogeochemical cycles. The protein content of chrome grain leather (CGL), chrome-free grain leather (FGL) and chrome-free suede leather (FSL) exceeded 60
Chronic wounds are marked by persistent inflammation that disrupts normal tissue repair. Growing attention is being directed toward dietary supplements as non-pharmacological strategies to support wound healing. This study evaluated the therapeutic potential of a specific formulation of bioactive fish-derived collagen peptides, Naticol®, in promoting cutaneous repair. The results demonstrated that oral supplementation with Naticol® accelerated excisional wound closure in type 2 diabetic mice by restoring essential histological features of healthy skin and enhancing collagen production. This effect is achieved through the establishment of an antioxidant and anti-inflammatory wound microenvironment, the enhancement of scavenger-dependent efferocytosis, and the modulation of MMP9/TIMP1 ratio in favor of tissue remodeling. Notably, Naticol® drove transcriptional reprogramming of human dermal fibroblasts and monocytes toward antioxidant, anti-inflammatory, and pro-repair phenotypes. In human keratinocytes, Naticol® increased migratory capacity, further contributing to tissue regeneration. Consistent with in vivo findings, Naticol® treatment improved wound healing in human skin explants by reinforcing an antioxidant, anti-inflammatory, and pro-reparative microenvironment. These results highlight Naticol®, a fish-derived bioactive collagen peptide preparation, as a promising functional food component, providing an innovative complementary approach for the management of chronic wounds.
This study aimed to identify anti-photoaging peptides in porcine skin and to elucidate their bioactive mechanisms using physicochemical property prediction, molecular docking, cell experiments, and network pharmacology. Four collagen peptides were identified from porcine skin hydrolysates via ultrafiltration, gel chromatography, and multi-pathway molecular docking. Among them, FGPYGF and GPPSGGFG exhibited superior photoprotective efficacy which increased the viability of UVB-damaged HaCaT cells to 72.15
Collagen-based fillers are increasingly recognized as versatile biomaterials for soft-tissue augmentation, yet evidence guiding the enzymatic management of collagen-associated complications remains limited. Here, we performed a systematic characterization of two National Medical Products Administration-approved porcine type I collagen fillers (PCFs), glutaraldehyde cross-linked PCF (CL-PCF) and uncross-linked PCF (UCL-PCF), using hyaluronic acid (HA) filler as a clinical benchmark. CL-PCF exhibited superior mechanical robustness and markedly enhanced resistance to collagenase degradation relative to UCL-PCF. In a rabbit ear embolization model, both PCFs induced significantly milder vascular ischemic manifestations than HA. In vivo enzymolysis assessment in SD rats demonstrated that collagenase concentrations ≤ 300 IU/mL effectively facilitated the controlled degradation of PCFs without inducing notable tissue injury, whereas higher concentrations resulted in extensive matrix loss, hemorrhage, and focal skeletal muscle lysis with inflammatory infiltration. This study provides the first integrated mechanistic and safety-oriented framework for understanding the enzymolysis of collagen fillers and optimizing collagenase-based interventions. These findings offer clinical guidance for complication management and inform evidence-based decision-making in collagen filler applications.
This study explores the potential of upcycling wet-white leather shavings as a filler in thermoplastic polyurethane (TPU) composites for fused filament fabrication (FFF). Leather waste was chemically analyzed to ensure compliance with environmental and safety regulations before being incorporated into TPU at varying concentrations (10 wt
With the depletion of petroleum resources, biomass has been widely applied as an alternative to petroleum-based feedstocks. In this work, a lightweight tannin-lignin-phenolic carbon foam (TLCF5−ME) with excellent smoke suppression was developed. The foam precursor was prepared by substituting 30 wt
Electronic skin (e-skin) holds significant potential for applications in health monitoring and human-machine interaction. However, conventional materials are often limited by poor biocompatibility and mechanical mismatch with biological tissues. Collagen and its derivatives, as naturally derived biopolymers, have emerged as an ideal matrix for constructing high-performance e-skin due to their exceptional biocompatibility, tunable biodegradability, mechanical properties that closely match human skin, and bioactivity endowed by abundant cell-recognition motifs. This review systematically presents the biomimetic design principles and advanced fabrication strategies of collagen-derived e-skins (CDE-Skins), including structural biomimicry, diversified manufacturing techniques, and conductive functionalization. It further examines their performance and underlying mechanisms in multimodal sensing, such as tactile, thermal, humidity, and biochemical sensing, elucidating the origins of their high sensitivity and stable signal response. The article also highlights representative applications in personalized telehealth monitoring, wound protection and therapy, and human-machine teleoperation. Concurrently, it outlines current challenges and offers perspectives on future research directions. This work aims to provide a comprehensive theoretical foundation to advance technological innovation and accelerate the practical translation of biocompatible e-skin technologies.
Ultraviolet (UV) irradiation is a major cause of photoaging, driving oxidative stress, inflammation, and extracellular matrix (ECM) degradation. Collagen is central to dermal integrity, yet animal-derived sources pose immunogenic and pathogen risks, while recombinant collagens reported to date often lack the stable triple-helical architecture required for bioactivity. Here, we present a triple-helical recombinant humanized type I collagen (THRCI) that combines native-like conformation with excellent biosafety and regenerative efficacy. THRCI supported fibroblast adhesion, proliferation, migration, and collagen synthesis, while suppressing intracellular reactive oxygen species and pro-inflammatory cytokines. In zebrafish, THRCI reduced oxidative stress and alleviated UV-induced caudal fin atrophy. In a murine model of acute UV photodamage, topical THRCI accelerated epidermal recovery, restored hydration and barrier function, increased dermal density, and promoted collagen fiber remodeling, while downregulating IL-6, IL-1β, MMP-1, and MMP-9. Collectively, these findings indicate that THRCI exhibits effective photodamage-repair properties in our established models and represents a promising animal-free collagen biomaterial for skin regeneration.
The residual issue of 2,4,5-trichlorophenol (2,4,5-TriCP) affects the leather industry because excessive 2,4,5-TriCP levels are detected in several finished leather products. This study reports the feasibility of using ecofriendly cyclodextrins (CDs) for 2,4,5-TriCP removal from pickled hide via host-guest interactions. Molecular docking, fluorescence spectroscopy, and quartz crystal microbalance with dissipation monitoring results confirmed that β-CD was suitable for 2,4,5-TriCP removal owing to its appropriate cavity structure. Batch elution experiments were performed to evaluate the influence of key parameters on the removal efficiency of β-CD, including time, temperature, sodium chloride (NaCl), β-CD concentrations, and the number of elution cycles. The mentioned optimal elution conditions were identified: 8
Abstract Dehairing proteases are eco-friendly alternatives to chemical dehairing process. Yet, their widespread industrial adoption requires focused research on key factors influencing their efficacy. Earlier research on two microbial proteases, SP01 (from Bacillus cereus VITSP01) and SP02 (from Brevibacterium luteolum VITSP02), revealed a correlation between substrate specificity for proteoglycans and dehairing efficacy. Herein, a comprehensive comparative analysis of their biochemical, thermodynamic, and molecular characteristics was performed to elucidate the determinants of their performance. In comparison to SP01, SP02 could cleave skin proteoglycans and dehair goat skins efficiently at lower temperatures (15 °C and 37 °C). Additionally, it exhibited thermolability, lower activation energy (Ea = 27.003 kJ mol−1) and tolerance to 10% SDS, non-ionic detergents, and 20% NaCl, while Ca2+ had a stabilizing effect on its structure. The protease genes of SP01 and SP02 were identified to be trypsin-like peptidase domain-containing protein and S8 family peptidase, respectively. The docking and molecular dynamics simulation revealed stabler interactions between proteoglycans and SP02 compared to SP01. The penetration of SP02 was faster than that of SP01 through skin matrix, probably due to its lower molecular weight (around 30 kDa), pI (about 4.6), proteoglycan degrading property, and smaller Rg and Rh. In silico structural analyses suggested some salient structural features responsible for the cold tolerance of SP02, and the resultant structural flexibility along with a larger catalytic pocket and longer multiple substrate-interacting tunnels could enable better substrate accommodation. In conclusion, SP02 was demonstrated as a potential dehairing enzyme with cold tolerant structural features. This study revealed some key determinants influencing its efficacy and stability, thereby implying improvements for process optimization. Graphical Abstract
Abstract This comprehensive review examines the application of life cycle assessment (LCA) in the leather industry, emphasizing its pivotal role in advancing circular economy integration. Through literature analysis and case studies, this review demonstrates how LCA facilitates animal by-product valorization, waste minimization, and material circularity, transforming traditional leather production into a paradigm of resource efficiency. Key environmental hotspots are identified across system boundaries: animal husbandry dominates Cradle-to-Grave impacts, while chemical usage (e.g., chrome agents) and energy-intensive processes prevail in leather processing, modulated by regional energy mixes. Emerging sustainable technologies and waste valorization innovations show promise in curbing ecological footprints. However, challenges persist, including methodological inconsistencies, data shortages, and regional disparities. To overcome these challenges, the review advocates for unified sector-specific databases, multidimensional assessment frameworks, and AI-driven modeling. Ultimately, LCA emerges as an essential tool for impact quantification, circular transitions, and sustainable industry evolution. Graphical Abstract
Abstract Conventional immunotoxicological approaches are often insufficient to comprehensively elucidate the complex immune responses that may arise during the degradation, metabolite generation, and tissue integration of protein-based medical devices. To address this limitation, we established and applied a six-tiered, stepwise immunological evaluation framework in an appropriate murine model, aiming to systematically characterize the immunological risks of proteinaceous biomaterials. This framework sequentially incorporates baseline immune screening, marketed product comparison, interspecies differentiation, dose–response validation, temporal dynamics assessment, and delayed response detection. By integrating multiple dimensions of readouts, including antibody levels (IgG, IgM, IgA), cytokine profiles (IL-2, IL-6, IL-12p70, IFN-γ, TNF-α), complement activation (C3, C4, C5), immune cell phenotyping, and splenic lymphocyte functionality, the framework establishes a structured, quantifiable, and scalable evaluation pathway. Using recombinant human collagen for injectable fillers as a model material, we demonstrated that this strategy effectively distinguishes diverse immune response types and differentiates material-intrinsic effects from interspecies artifacts, thereby confirming its applicability and interpretive strength in immunological safety assessment of protein-based biomaterials. Collectively, the proposed six-tiered evaluation strategy not only overcomes the limitations of traditional single-parameter or short-term assessments, but also provides a scientifically rigorous and systematic methodology that can serve as a versatile tool for both immunological evaluation and design validation of protein-based and other complex biomacromaterials. Graphical Abstract
Abstract The reliance on fossil-derived compounds in most conventional retanning agents faces a challenge to the sustainable development of the leather industry. Consequently, the development of environmentally friendly biomass-based retanning agents is urgently needed. In this research, a novel sucrose-based amphoteric retanning agent (GLS) was synthesized with a weight-average molecular weight of 3.48 × 104 g/mol. The molecular structure of GLS was determined using FT-IR, 13C-NMR, XPS, and EA. The GLS exhibited a favorable isoelectric point (pI = 4.68) as a retanning agent. At a 10% dosage, GLS retanning of wet-blue resulted in a 14.42% thickness increase, substantially greater than that achieved with commercial amino resin (CML, 6.77%) and acrylic resin (LP, 10.8%) retanning agents. GLS also exhibited superior absorption (87.13%) compared to CML (75.27%) and absorption comparable to LP (89.2%). Notably, GLS improved the uptake of subsequent anionic fatliquoring agents compared to CML and LP. Moreover, GLS-retanned leather displayed good thermal stability and commendable physical and mechanical properties. The BOD₅/COD value of the GLS retanning wastewater was 0.48, indicating its excellent biodegradability. Life cycle assessment further highlighted the environmental benefits of GLS compared to LP and CML. These findings position GLS as a promising biomass-derived amphoteric retanning agent with the potential to displace conventional fossil-derived alternatives. Graphical Abstract
Abstract Human amniotic membrane (AM), a valuable natural biomaterial, is increasingly used in clinical applications. However, its limited mechanical strength and rapid degradation restrict broader use. To address these limitations, we developed a spray-applied crosslinking method for dry AM. A spray delivery of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) with N-hydroxysuccinimide (NHS), combined with a hydrogen-bond-supplementing solution (oxygen-containing compounds), produced a crosslinked dry AM with improved mechanical strength and enhanced resistance to enzymatic degradation in vitro. The EDC/NHS chemistry promoted the formation of covalent bonds within the collagen network, increasing tensile strength and enzymatic stability, while the hydrogen-bond supplement preserved the membrane’s native flexibility after rehydration. The maximum uniaxial tensile fracture stress of the crosslinked AM increased by 156.1%, and the weight loss ratio of enzymatic degradation decreased from 100% to 63.6%. These results indicated that the spray crosslinking protocol yielde a mechanically robust, enzymatically stabilized AM without compromising flexibility, and might expand the membrane’s clinical applicability. Graphical Abstract
