Fatliquor migration within the leather matrix may lead to the formation of fatty spew, oil patches and fogging, posing challenges to the production of high-quality leather. Currently, it lacks a straightforward and effective method for analyzing fatliquor migration behavior. This investigation introduces a novel approach for analyzing fatliquor migration by measuring its spreading area on collagen fiber membranes. By applying 300 mg of fatliquor onto 0.5 mm square membranes (10 cm × 10 cm), distinct oil spots were observed, enabling analysis of migration behavior. Using stearic acid as a standard reference compound effectively minimized the influence of different leather sections on fatliquor migration. Fatliquors with low molecular weight, low melting point and high aliphatic ester content exhibited obvious migration potential. Organic-tanned leathers and sulfated fatliquors displayed weak interactions, resulting in easy fatliquor migration within the leather. Conversely, metal-tanned leathers and phosphorylated fatliquors demonstrated strong interactions, effectively hindering migration. This research provides valuable practical and theoretical insights for developing effective strategies to prevent and control fatliquor migration in leather production.

Despite its potential as a metal-free tanning agent capable of eliminating Cr pollution in the leather industry, the conventional preparation of poly(carbamoyl sulfonate) faces challenges, such as the extensive use of low-boiling organic solvents and low blocking ratios of –NCO groups. Herein, a liquid sulfonate chain extender, 2,3-dihydroxypropanesulfonic acid triethylamine salt (DHPSTEA), was initially synthesized. A series of poly(carbamoyl sulfonate) tanning agents (CTAS) were then synthesized using DHPSTEA and various diisocyanates as reaction monomers, with sodium bisulfite serving as the blocking agent and without utilizing organic solvents. CTAS demonstrated a blocking ratio of > 99% and satisfactory stability under acidic conditions at room temperature. Application experiments revealed that CTAS exhibited excellent tanning performance, with the parent diisocyanate monomer markedly influencing their tanning properties. CTAS synthesized with dicyclohexylmethane-4,4′-diisocyanate resulted in optimal product performance, yielding a shrinkage temperature of 83.2 °C at a 6% dosage. CTAS-tanned leather displayed excellent collagen fiber dispersion, yellowing resistance and mechanical properties. Additionally, CTAS is easy to biodegrade (BOD₅/COD > 0.45). Thus, this novel metal-free tanning agent holds a great potential as a sustainable alternative to traditional chrome tanning agent.

To enhance the utilization of pesticides and reduce environmental risks, we constructed the magnetic recyclable and dual stimulus-responsive microspheres to achieve on-demand pesticide release. Magnetic multi-shell hollow mesoporous organosilicon nanoparticles (mMSN) were prepared by one-step hydrothermal method and loaded with pesticide avermectin (A@mMSN), afterward A@mMSN was coated with gelatin through emulsification and chemical cross-linking to prepare A@mMSN@G microspheres (21.5 ± 9.7 μm). After being absorbed by the pests, the gelatin layer was hydrolyzed with the neutral protease, and the disulfide bonds within mMSN framework were decomposed by glutathione (GSH), endowing A@mMSN@G microspheres with enzyme and GSH responsiveness to achieve sustained avermectin release till 7 days (about 3.5 times that of the commercial avermectin emulsion). Importantly, the A@mMSN@G microspheres containing Fe₃O₄ nanoparticles could be easily magnetically collected from soil with a recovery ratio of 63.7%, to reduce the environmental risks. With excellent biosafety, A@mMSN@G microspheres showed outstanding pest control effects till two weeks and the growth of cabbage was not affected by it. Therefore, based on the recyclability and dual stimulus-responsive controllable release, the fabricated A@mMSN@G microspheres have broad application potential in pesticide delivery.

Despite advances in synthetic vascular grafts, replicating the dynamic biological functions of native microvasculature remains a critical challenge in cardiovascular tissue engineering. While polymer-based conduits offer scalability and dimensional versatility, the inherent bioinert nature leads to high failure rates in < 6 mm diameter applications due to thrombotic complications and mechanical mismatch with host tissue. Decellularized matrices (dECM) scaffolds emerge as a biologically strategic alternative, preserving crucial vascular basement membrane components and biomechanical cues through collagen/elastin retention. The present review systematically elaborates the research advancements, critical determinants, and practical challenges in utilizing dECM for tiny-diameter artificial vessels (inner diameter < 3 mm), while proposing three forward-looking solutions to address clinical translation barriers: (1) matrix optimization strategies through diameter-specific compliance matching and elastin reconstitution; (2) sterilization and preservation protocols preserving structural integrity with controlled immunogenicity; (3) immunomodulatory engineering via macrophage polarization regulation. The proposed methodologies establish innovative avenues for the engineering and clinical transplantation of tiny-diameter artificial vessels.

Tetrakis(hydroxymethyl)phosphonium sulfate (THPS) is commonly used in leather production that leads to its presence in tannery wastewater. As a typical organic phosphorus pollutant, THPS poses potential threats to both the ecological environment and human health. Herein, this investigation used the microscale zero-valent iron (mZVI)/O₃ process to eliminate THPS from aquatic environments. The mZVI/O₃ system demonstrated superior removal performance, achieving high removal efficiencies of total phosphorus (TP), organic phosphorus (OP), and chemical oxygen demand (COD) compared to traditional systems (i.e., mZVI alone, O₃ alone, Fe²⁺/O₃, and Fe³⁺/O₃). Moreover, batch experiments were conducted to optimize the key operational parameters (such as initial pH, mZVI dosage, O₃ concentration, and stirring rate). The TP, OP, and COD removal efficiencies in the mZVI/O₃ system reached 97.10%, 97.31%, and 81.56% within 20 min, respectively, under optimized conditions. Based on the experimental results and characterization analysis, the THPS degradation mechanism by the mZVI/O₃ system was primarily a combination of oxidation (60.37% ± 7.41%) and flocculation (39.63% ± 7.41%). Furthermore, the mZVI/O₃ system demonstrated unprecedented removal performance in various actual wastewater samples. The system eliminated organic pollutants and improved biodegradability of actual wastewater. This study not only establishes the mZVI/O₃ process as a robust, cost-effective, and environmentally sound approach for OP degradation but also offers substantial promise for practical wastewater treatment applications.

Mid-facial depression is a key sign of facial aging, primarily caused by the loss of collagen leading to depletion of the extracellular matrix (ECM). However, the existing fillers for soft tissue augmentation have shown certain limitations in repairing mid-facial depression. Therefore, we herein report the development of a novel recombinant humanized type III collagen gel (C3Gel) through rational design and modification of a commercially available recombinant type III humanized collagen lyophilized fiber product. Both biological activity and tissue repair mechanisms of C3Gel were systematically evaluated in vitro and in vivo. C3Gel formed a dense fibrous structure around cells, significantly improving the ECM environment and providing strong support for cells, thereby promoting cell adhesion, migration, and proliferation. After injection of C3Gel into the dorsal region of rats, we observed a significant increase in the expression of type I collagen and elastin that improved tissue mechanical properties and elasticity. High-throughput RNA sequencing analysis revealed that C3Gel activated the integrin signaling pathway to improve binding between cells and ECM, resulting in the increased expression of downstream genes by activating the PI3K-Akt pathway which promoted the production of ECM components, such as collagen and laminin. At the same time, the expression of matrix metalloproteinases was inhibited to maintain ECM stability. Moreover, C3Gel is not carcinogenic in mice. Therefore, C3Gel demonstrates excellent biocompatibility and significant tissue repair ability, offering a safe, efficient, and long-term stable solution for mid-facial soft tissue augmentation, while providing new insights for other applications in regenerative medicine.

Collagen, an abundant extracellular matrix protein in food-producing animals, is widely integrated into food systems for its unique physicochemical properties. Oral collagen-based supplements have received increasing attention for their potential to enhance overall well-being. This review aims to provide valuable insights into the application of oral collagen supplements in food systems, promoting their broader use in food processing, preservation, and the development of functional foods. Specifically, the applications of oral collagen-based supplements in functional foods, focusing on their biological activities, health benefits, and functional properties are summarized. Importantly, their molecular mechanisms of biological activities are critically discussed, including antioxidant, angiotensin-converting enzyme inhibitory, and dipeptidyl peptidase IV inhibitory activities. The health benefits of oral collagen-based supplements, particularly in improving skin, immune, and gastrointestinal health are also explored. Additionally, various functional properties of collagen-based supplements are evaluated, including their stability, bioavailability, taste masking, and sensory attributes.

Cell migration is a fundamental biological process that plays a crucial role in both physiological and pathological conditions, and is largely influenced by the complex microenvironment, particularly the extracellular matrix (ECM), a macromolecular network that governs various cellular interactions. Extensive research has established that ECM-cell interactions are critical in multiple biological processes, with some directly regulating cell migration. Among ECM components, collagens stand out as key regulators of cell movement. However, existing reviews have provided only limited perspectives on the role of collagen-based biomaterials in directing migration across different cell populations. This gap in knowledge hinders a comprehensive understanding of collagen’s full potential. Drawing from systematic literature and our ongoing research, this review aims to summarize advancements over the past five years in the application of collagen-based biomaterials for modulating cell migration. The discussion primarily focuses on three pivotal cell types: stem cells, immune cells, and cancer cells. By shedding light on the functions, mechanisms, and therapeutic potential of collagen in cell migration, this review will contribute to the development of innovative collagen-based biomaterials with applications in wound healing and tissue regeneration.

Developing chrome-free tanning agents to manufacture eco-leather products is the most promising way to address chrome pollution and achieve a sustainable leather industry. Herein, we report on a facile strategy to synthesize a novel biomass-based epoxy tanning agent (BET) based on sucrose and γ-(2,3-epoxypropoxy) propytrimethoxysilane (KH560). FTIR, XPS, ²⁹Si NMR, and GPC analyses confirmed the reaction between sucrose and KH560 via forming Si–O–C bonds, suggesting the successful preparation of BET. The subsequent application experiments showed that the BET-tanned leather demonstrated superior performance with a well-organized collagen fiber network and a shrinkage temperature exceeding 80 °C, outperforming commercial TWS-tanned leather in thermal stability during post-tanning and resistance to yellowing. Moreover, the BET-tanned crust leather exhibited enhanced tensile strength (25.65 vs. 16.18 N/mm²) and tear resistance (84.01 vs. 60.71 N/mm) compared to TWS-tanned crust leather, along with reduced extensibility under a specific load and at break. Compared with the TWS-tanned crust leather, the BET-tanned crust leather also displayed superior smooth grain surface, dyeing uniformity, softness, and fullness. These promising results pave the way for developing alternative chrome-free tanning agents, aiding the sustainable development of the leather industry.

Hollow polymer microspheres (HPMs) were synthesized through emulsion polymerization for application in leather retanning, offering a novel approach to lightweight leather processing. Seed emulsion polymerization enabled the controlled synthesis of four distinct HPM sizes ranging from 300 to 650 nm. Comprehensive characterization revealed that HPMs exhibited distinct hollow structures, narrow particle size distributions, and excellent storage stabilities in emulsion form. The retanning performance of HPMs was evaluated in wet-blue. The HPMs demonstrated excellent permeation during the retanning process, selectively filling the gaps among the fibers, particularly larger spaces. The maximum thickening rate of HPM emulsion (solid content of 10%) retanned leathers reached 18.01%, surpassing the 11.32% achieved with the commercial acrylic resin retanning agent (AR, solid content of 30%) at the same dosage. The maximum absorption of HPM (88.31%) closely approached that of AR (90.23%). Furthermore, HPM retanned leathers showed satisfying performances in physical and mechanical properties. These findings demonstrate the potential of HPMs as lightweight and highly selective filling retanning agents with excellent thickening and absorption properties, offering an attractive alternative to traditional retanning agents.

Uranium plays a pivotal role in nuclear energy production, and extracting it from seawater offers a promising solution to alleviate shortages in land-based uranium resources. However, the marine environment with ultra-low uranium concentrations, high salinity, and microbial activity poses significant extraction challenges, compounded by selectivity and cost limitations in current methods. In the present investigation, an anti-biofouling amino oxime-functionalized collagen/sodium alginate aerogel (CF-AO/SA) was fabricated using leather waste-derived collagen. The dual cross-linked CF-AO/SA network, enhanced by Zn²⁺ incorporation, showed improved structural stability and antibacterial properties, as well as high uranium adsorption capacity, selectivity, and reusability. It achieved 320.7 mg g⁻¹ in 14 ppm uranium solution and maintained 78.6% removal efficiency after five cycles. Additionally, the removal rate of uranium was 89% in simulated seawater. Field tests in Zhuhai's Jinwan District (113.35° E, 21.99° N) showed 5.16 mg g⁻¹ uranium adsorption and excellent mechanical strength after 30 days in seawater. Furthermore, the production cost of CF-AO/SA was estimated at $3.652 per kilogram, which is lower than other reported adsorbents. The newly developed bio-based aerogel beads have substantial potential for practical applications for uranium capture in seawater and provide a novel high-value utilization way for leather wastes.

Collagen, recognized as the primary structural component of human skin, is essential for preserving dermal integrity and function. Its progressive depletion has been closely associated with structural deterioration of the dermis and the visible signs of skin aging. Among current therapeutic strategies, the injection of exogenous collagen has been established as an effective method for alleviating aging-related skin changes. In the present study, a comprehensive evaluation was conducted to assess the injectability, cellular interactions, and photoaging repair efficacy of recombinant human collagen type III (RHC). The RHC solution was found to demonstrate favorable injectability and support the adhesion and chemotactic behavior of L929 cells, while also upregulating the expression of type I and type III collagen. In co-culture systems with lipopolysaccharide-stimulated macrophages, RHC treatment suppressed macrophage proliferation and reduced the production of proinflammatory cytokines, suggesting notable immunomodulatory properties. Upon intradermal injection of RHC into photoaged rat skin, an increased density of dermal collagen fibers was observed, accompanied by a more organized and uniform fiber arrangement. Additionally, hydroxyproline content and the expressions of collagen I and III were markedly elevated in the RHC group compared with the control and hyaluronic acid groups. Collectively, these findings suggest that RHC holds considerable promise as a therapeutic agent for both medical and cosmetic purposes targeting the restoration and maintenance of youthful skin characteristics.

Sea cucumbers suffer from non-enzymatic deterioration during heat processing and storage, which significantly devaluates the product. In the present investigation, it was found that ι-carrageenan oligosaccharide (ι-CO) synergized with Ca²⁺ is able to protect sea cucumbers from deterioration. The textural strength and water-holding capacity of the sea cucumber body wall were improved after treatment with ι-CO and Ca²⁺, and the collagen structure was more resistant to destructive experiments. In addition, pepsin-solubilized sea cucumber collagen (SCC) was extracted and demonstrated that the positive effect was due to co-gelation between ι-CO and collagen supported by rheological and thermal property studies. Furthermore, molecular dynamics simulations confirmed that ι-CO spontaneously binds to SCC, while Ca²⁺ promotes the crosslinking strength of the ι-CO-SCC mixed gel and enhances its water-holding capacity and mechanical strength. Therefore, the ι-CO/Ca²⁺ can permeate and stabilize collagen hydrogel, which provides valuable information for the development of new food additives to improve the texture of collagen-based foods.

Harnessing the collagenous structural hierarchy of leather is an intriguing strategy for developing the next-generation skin-friendly e-skins with integrated powerful multifunctional sensory capabilities. The current development of e-skins is significantly hindered by the limited breathability for the long-term wearability and the complexity of integrating multimodal sensors within confined device dimensions. The proteinous composition of leather is capable of providing e-skins with exceptional skin affinity, biocompatibility and water vapor permeability, thus guaranteeing the long-term wearing comfortability. The inherent hierarchical fibrous structure of leather combined with the unique reversible cross-scale deformation behaviors enables the in situ construction of highly sensitive microstructured sensors for realizing the miniaturization and integration of multimodal sensors within the constrained space of leather. As a consequence, the development of leather-based e-skins paves a new way for advancing leather industry from traditional manufacture to cutting-edge innovation.

Vegetable oil-based waterborne polyurethanes (WPU) have gained significant attention in the leather industry as sustainable coatings, yet inherently suffer from limited bio-based content, hydrophobicity, and low-temperature resistance due to their reliance on low-molecular weight (Mw) hydrophilic chain extenders and highly functionalized bio-based polyols. To overcome these challenges, we developed a long fatty chain-based design strategy by synthesizing a high-Mw castor oil emulsifier (COE) and two bio-based diols, successfully preparing a novel series of WPU emulsions. When the COE content reached 30%, the emulsions demonstrated good stability while achieving a high-bio-based content of 70.94%. The incorporated long fatty chains endowed the WPU films with good hydrophobicity (water contact angle > 90°), exceptional water resistance (water absorption < 2%), chemical resistance, and self-cleaning properties. Moreover, these high-bio-based content films exhibited tunable thermomechanical performance, including enhanced low-temperature resistance (T_g = 2.8 °C) and improved elongation with increasing Mw, while maintaining excellent thermal stability (T_d5% > 200 °C). This work provides an effective approach for developing sustainable WPU for leather applications with balanced performance properties through strategic molecular design of long fatty chain structures.

Malignant melanoma, a highly aggressive malignancy, necessitates innovative therapeutic strategies integrating biomaterial innovation with multimodal treatment modalities. Herein, we report the development of a collagen-derived bioelectronic skin (c-ADM) nanoengineered via interfacial assembly of porcine acellular dermal matrix (ADM)—a natural collagen-rich scaffold—with conductive poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and copper sulfide nanoparticles (CuS-NPs). This hybrid system synergizes photothermal ablation, stimuli-responsive drug delivery, and electrostimulation (ES) for comprehensive postoperative melanoma management and tissue regeneration. The c-ADM platform exhibits superior mechanical robustness, enzymatic resistance, and biocompatibility, enabling real-time motion monitoring while maintaining structural integrity in dynamic physiological environments. Leveraging the photothermal efficiency of CuS-NPs, localized hyperthermia (ΔT > 40 °C) under near-infrared (NIR) irradiation induces irreversible melanoma cell apoptosis. Concurrently, laser-triggered temperature-responsive drug release enables synchronized photothermal-chemotherapy, with sustained doxorubicin release profiles at tumor sites. Notably, pH-responsive Cu²⁺ liberation from CuS-NPs facilitates intelligent functional switching: bactericidal activity at tumor microenvironment pH (5.0–6.0) and pro-regenerative effects under physiological pH (7.4) for wound healing. In vitro/in vivo assessments confirm c-ADM’s dual therapeutic efficacy including ES-enhanced cancer cell death via mitochondrial dysfunction and accelerated full-thickness skin regeneration through collagen remodeling and angiogenesis modulation. This work establishes a collagen-based bioelectronic scaffold for personalized oncological care, integrating intraoperative tumor eradication, postoperative surveillance, and adaptive tissue reconstruction.

As consumers prioritize safer and more sustainable skincare ingredients, the traditional facial mask industry faces challenges due to the use of non-biodegradable materials and chemical preservatives that irritate the skin and harm the environment. In the present investigation, an innovative all-biomass solid facial mask was developed using electrospinning technology to incorporate naturally effective ingredients into bio-based fibers made of gelatin and pullulan polysaccharide. This process produced a nanofiber-based, fast-dissolving facial mask with essence uniformly embedded throughout the fibers. Unlike traditional facial masks that rely on preservatives, this solid mask avoids their use while offering excellent water and moisture retention. Owing to its nanostructured architecture and water-soluble fiber materials, it dissolves completely in water within just 7 s. Yak skin collagen peptides incorporated into the nanofiber film demonstrated strong antioxidant activity, scavenging 88.3% of DPPH free radicals. Biocompatibility testing combined with animal skin and eye irritation testing further confirmed the safety of the facial mask. This innovative approach not only supports the sustainable development of environment and resources but also delivers safer, more effective skincare solutions for consumers.

The application of peptides as inhibitors of skin aging is a promising area of research. Previous researches have predominantly focused on extracting anti-aging peptides from the collagen of specific animals, while large-scale rapid screening and analysis of the structure–activity relationships of these peptides have been scarcely reported. In the present investigation, we developed a machine learning model for screening potential anti-skin-aging peptides (PASAPs), achieving a Matthews correlation coefficient (MCC) of 0.927 ± 0.044 and balanced accuracy (BACC) of 0.963 ± 0.022. These metrics surpassed those of the existing PeptideRanker model, which is widely used in bioactive peptide studies. Based on in silico screening, we identified and synthesized six novel PASAPs derived from tilapia collagen: KKHVWFGE, NGTPGAMGPR, PGAAGLKGDR, DGAPGPKGDR, TGPVGMPGAR, and GAPGGAGGVGEPGR. In vitro assays revealed that all six peptides exhibited significant inhibitory activity against aging-related enzymes, with the most pronounced effects on elastase and collagenase. A comprehensive analysis of the C-terminal amino acid residues indicated that the presence of arginine (R) at the C-terminus notably enhanced peptide binding to aging-related enzymes. This enhancement was attributed to an increased number of hydrogen bonds and stronger chemical interactions, which augmented the aging-related enzyme inhibitory activity of the peptides. In summary, this study proposed an effective strategy for discovering PASAPs from collagen and validated the machine learning model through experimental evidence. Structure–activity relationship insights can guide the synthesis of bioactive peptides and the selection of proteases for bioactive peptide production.

Full-thickness skin wounds pose a considerable clinical challenge because of the limited capacity for self-regeneration. Acellular materials derived from animals offer a promising solution to this issue. In the present investigation, an acellular scaffold is prepared from yellowfin tuna skin (Thunnus albacares) for skin regeneration application by comparing the efficacy of three chemical decellularization agents: sodium hydroxide (NaOH), Triton X-100 (TT), and sodium dodecyl sulfate (SDS). The impact of these agents on the resulting acellular dermal matrices was evaluated by assessing collagen preservation, DNA removal, residual fat and ash content, and structural integrity using hydroxyproline assay and chemical composition analysis. Mechanical properties, swelling behavior, degradation rate, water vapor transmission rate, moisture loss, and biocompatibility of the acellular membrane were also characterized. Furthermore, the regenerative potential of these samples was assessed in a porcine full-thickness skin defect model. The results demonstrated that all three decellularization methods effectively removed cellular components, with varying degrees of collagen preservation and ECM structural alteration. TT treatment yielded the highest collagen retention and a relatively intact fibrous structure, while NaOH caused significant structural damage. Mechanical testing revealed that hydration significantly improved the elasticity of TT- and SDS-treated samples. In vitro biocompatibility assays showed no significant cytotoxicity or hemolysis. These findings suggest that the acellular membrane holds promise as a biomaterial for skin regeneration applications due to its effective decellularization, preserved collagen structure, and favorable biocompatibility.

The efficient biosynthesis is important for the sustainable development of lignocellulosic ethanol industry, but it is limited by furfural stress produced with cellulose pretreatment. Collagen peptide (CP), as an affluent protein resource, considerably improved the tolerance of Saccharomyces cerevisiae against furfural stress. When the furfural concentration was 2 g/L, the residual sugar concentration was reduced from 122.39 to 8.90 g/L, and the final ethanol yield increased from 30.69 to 87.27 g/L in the presence of CP. In addition, the ethanol yield in CP containing media was higher than those in other peptides. Transcriptome analysis showed CP can improve the expression of genes (FBA1, PDC1, PDC6, and ENO1) associated with glycolysis to promote sugar utilization, and enhance ethanol biosynthesis under furfural stress, which were further verified by quantitative real-time PCR. These results indicated that CP is a promising protectant and accelerator for bioethanol biosynthesis.

Calcification, infection, and inflammation are common complications associated with the in vivo application of biological patches. Porcine acellular dermal matrix (pADM), composed mainly of collagen with excellent bioactivity, is widely utilized as a substrate for such patches. However, integrating multiple therapeutic functions into pADM remains a significant challenge. To overcome this limitation, a hydrogel-encapsulated pADM patch (H-Cur-pADM) was developed, aiming to provide barrier protection and multifunctional enhancement. This design involves the in situ formation of a curcumin-loaded hydrogel (GelMA-DTT-Cur) on the surface of pADM via a thiol–ene click reaction. The resulting hybrid not only reinforces the anticalcification capacity of the patch but also imparts anti-infective and anti-inflammatory properties. By combining the mechanical support of pADM with the functional versatility of the hydrogel, this innovative approach enhances the overall performance of the biological patch. The GelMA-DTT-Cur hydrogel layer demonstrated robust structural integrity, interconnected porosity, and sustained release of curcumin micelles following a Fickian diffusion mechanism. In vitro, the hydrogel-encapsulated pADM displayed significant antibacterial activity against Escherichia coli and Staphylococcus aureus, good cytocompatibility, and pronounced anticalcification properties. In vivo studies showed that calcium deposition in the H-Cur-pADM group was only 5.2% of that observed in glutaraldehyde-cross-linked pADM after 21 days of implantation. The H-Cur-pADM patch also displayed strong anti-inflammatory effects and effectively promoted healing in an abdominal wall defect model. This work presents a novel strategy for improving the therapeutic performance of biological patches by integrating drug-loaded hydrogel encapsulation with pADM, offering promising potential for clinical applications in abdominal wall repair.

Photoaging skin caused by excessive UV radiation has been one of the most common skin diseases, leading to wrinkles, hyperpigmentation, inflammation, and even skin cancer. Oral collagen supplements have emerged as a potential strategy for photoaged skin; however, they suffer from unclear molecular weights and high risk of disease transmission. Herein, we have for the first time developed a series of molecular weight-controllable oral yak skin collagen (OYC) by the molecular weight-directed enzymolysis-chromatography combined strategy. Toxicological studies indicated that OYC displayed good biocompatibility and no organ toxicity. Combo evaluations revealed that OYC contributed to the restoration of photoaged skin to healthy levels. Histological analysis demonstrated that OYC improved the histopathological changes, significantly accelerating the regeneration of collagen fibers. Antioxidant indicators analysis further indicated that OYC alleviated oxidative stress induced by UV irradiation. Notably, OYC with medium molecular weight (MOYC) exhibited the most effective anti-photoaging properties, likely due to its exceptional ability to scavenge reactive oxygen species, improved intestinal absorption, and optimal resistance to degradation. This orally administered yak skin collagen provides a new strategy and theoretical basis for the prevention and treatment of photoaged skin, offering broad prospects in the fields of nutritional supplements and skincare products.

Enzymatic unhairing is an environmentally friendly and efficient method for leather processing. However, controlling protease hydrolysis remains challenging, leading to incomplete hair removal and potential grain damage. In modern leather manufacturing, the synergistic application of proteases, lime, and sulfide is increasingly employed to achieve satisfactory hair-saving unhairing performance. This study investigated the action mechanism of calcium ions in modulating the hydrolysis of hide proteins by proteases and proposed a balanced enzyme-assisted unhairing process. Enzymological and fluorescence spectroscopy analyses revealed that calcium ions could enhance the enzymatic resistance of hide proteins, including noncollagenous proteins and collagen, by binding to them. This enhancement in enzymatic resistance was more pronounced for globular proteins than for collagen fibers. In detail, following the addition of 20 g/L calcium ions, the hydrolytic activity of neutral and alkaline proteases decreased by 66.7% and 57.9% on bovine serum albumin, and by 40.7% and 48.1% on collagen fibers, respectively. Furthermore, the performance of the five unhairing processes was evaluated by varying the sequence of lime and protease application and type of protease used. Results indicated that while calcium ions exerted a protective effect on hide proteins and reduced damage to collagen fibers, they simultaneously hindered the removal of undesired noncollagenous proteins during unhairing. Consequently, the sequential application of lime followed by proteases resulted in the inadequate removal of interfibrillar substances, leading to unsatisfactory leather quality. Additionally, compared with an alkaline protease, a neutral protease was more easily inhibited under alkaline unhairing conditions, posed a lower risk of damage to the hide grain. Therefore, the neutral protease–lime–sodium sulfide unhairing process was chosen as the optimal strategy. This process involves the addition of neutral protease (50 U/g hide) for 60 min, followed by 1.0% lime for 90 min and 2.0% sodium sulfide for 90 min. These findings provide scientific insights for designing a controlled and efficient approach to enzyme-assisted unhairing processes.

The practical implementation of lithium–sulfur (Li–S) batteries is hindered by their poor rate performance and rapid capacity fade, primarily due to the sluggish kinetics of polysulfide conversion. To overcome these challenges, a nitrogen-rich fibrous carbon (NFC) material was synthesized using gelatin and g-C₃N₄ as raw materials through a stepwise pyrolysis process. The unique fibrous microstructure of NFC endows it with high ionic and electronic conductivities, facilitating rapid Li ion and electron transports. Furthermore, nitrogen doping increases the electrochemical performance of the Li–S battery by improving polysulfide adsorption and conversion kinetics. Consequently, the Li–S battery incorporated with NFC demonstrates significantly improved rate performance, exhibiting a high discharge specific capacity of 721 mAh g⁻¹ at 4 C. Additionally, the pouch cell incorporating NFC displays a high average capacity of 821.6 mAh g⁻¹ over 40 cycles at 0.1 C, with high cycling stability and a capacity retention rate exceeding 96%. These results highlight the effectiveness of NFC in improving the cycle longevity of Li–S batteries, thereby heralding a significant stride forward in their practical implementation in energy storage systems.

The blending of natural rubber (NR) with cis-1,4-polybutadiene rubber (BR) has gained widespread attention due to its potential in enhancing the low temperature resistance and abrasion resistance of NR. However, the incompatibility between NR and BR as well as the non-uniform distribution of fillers often have an adverse impact on the mechanical properties. Herein, we propose a facile approach to modulate the multi-scale structures in NR/BR blends including polymer compatibility and filler distribution by introducing ethylene vinyl acetate (EVA) with varying vinyl acetate (VA) content as multifunctional compatibilizers. The results indicate that the cure characteristics (i.e., processability) and mechanical properties of NR/BR blends can be readily tailored through adjustment of the VA content in EVA. When the VA content in EVA is increased to 18% (EVA-18), the NR/BR blends simultaneously exhibit favorable processability and mechanical properties. The microstructural analysis demonstrates that the introduction of EVA-18 not only enhances the compatibility between NR and BR with significantly reduced domain size, but also improves fillers dispersion in the rubber matrix. The presence of EVA-18 at concentrations up to 20 parts per hundred of rubber (phr) in NR/BR vulcanizates improves the mechanical properties by approximately 24% compared to un-compatibilized NR/BR vulcanizates, which is superior to the most present studies. This work will be beneficial for the development of NR/BR blends in the industry and provide a guideline for designing efficient compatibilizers for other immiscible rubber blends.