Acta biomaterialia最新文献

{"title":"Emerging Chiral Nanozymes: Enantioselective Catalysis and Biomedical Applications.","authors":"Jian Zheng, Ruining Zhao, Hongxia Li, Yan Li, Xing Yang, Hongfang Zhao, Kunjie Wang, Xiaohui Niu","doi":"10.1016/j.actbio.2026.10.025","DOIUrl":"https://doi.org/10.1016/j.actbio.2026.10.025","url":null,"abstract":"<p><p>Chiral nanozymes are biomimetic materials that combine nanomaterials' unique physicochemical properties with enzyme-like catalytic functions. Their chiral microenvironments enable selective recognition and catalysis of substrate enantiomers, with demonstrated applications in biosensing, disease diagnosis/treatment, and antibacterial/anti-inflammatory therapies. This article provides a systematic review of the design and synthesis strategies, catalytic types, mechanisms of action, and biomedical application research progress of chiral nanozymes. In terms of design and synthesis, four strategies are emphasized, namely chiral ligand modification, the chiral template method, chiral self-assembly, and chiral defect engineering. In catalytic performance and mechanism, the redox activities such as peroxidase, oxidase, catalase, and superoxide dismutase, as well as esterase-/protease-like hydrolysis activity, were summarized. An in-depth exploration was conducted of the molecular mechanism by which chiral microenvironments synergistically regulate substrate binding and electron transfer through steric hindrance effects and multiple weak interactions. In addition, the latest research progress of chiral nanozymes in enantiomer recognition and detection, tumor chemodynamic/photodynamic/sonodynamic combination therapy, neurodegenerative disease protein aggregation intervention, and selective antibacterial and inflammatory regulation is also reviewed. Finally, the challenges and future development directions faced by chiral nanozymes in precise regulation of catalytic selectivity, long-term biological safety in vivo, and clinical translation are discussed. STATEMENT OF SIGNIFICANCE: 1. Four strategies for constructing chiral nanozymes: ligand modification, template induction, self-assembly, and defect engineering. 2. Mechanistic insights into how chiral microenvironments regulate oxidoreductase-like and hydrolase-like catalysis. 3. Biomedical applications, including chiral biosensing, tumor therapy, neurodegenerative disease intervention, and antibacterial treatment. 4. Critical evaluation of chiral-induced spin selectivity (CISS), the hurdles to clinical translation, and future directions for the intelligent design of chiral nanozymes.</p>","PeriodicalId":93848,"journal":{"name":"Acta biomaterialia","volume":" ","pages":""},"PeriodicalIF":9.6,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149198357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In vivo membrane engineering: An approach to remodeling cell interfaces.","authors":"Jiadai Jin, Jianqing Gao, Xinchi Jiang","doi":"10.1016/j.actbio.2026.10.026","DOIUrl":"10.1016/j.actbio.2026.10.026","url":null,"abstract":"<p><p>The cell membrane is a crucial interface that maintains cellular homeostasis and facilitates intercellular communication, playing a key role in regenerative medicine and immune regulation. To improve cell-targeting ability, immune evasion, therapeutic efficacy, and durability, membrane engineering has modified cells using physical, chemical, or biological techniques. Recent research on in vivo membrane engineering has highlighted approaches that avoid the complex steps of cell extraction and re-injection in cell therapy. Thus, by performing modifications directly within the physiological environment, this strategy preserves cellular activity and minimizes variability in in vivo adaptability, enabling more efficient cellular remodeling. This review systematically summarizes and forecasts the latest advances in in vivo membrane engineering strategies, including bioorthogonal chemistry, genetic engineering, in vivo membrane fusion, DNA nanotechnology, and trogocytosis. For each strategy, we discuss its underlying mechanisms, unique advantages, and current technical limitations. Furthermore, we evaluate the major challenges hindering clinical translation and propose potential directions for future research, aiming to provide a perspective for more precise, controllable, and safe cell therapy. STATEMENT OF SIGNIFICANCE: The cell membrane serves as a crucial interface for maintaining cellular homeostasis and facilitating intercellular communication, and thus plays a key role in regenerative medicine and immune regulation. In vivo membrane engineering enables direct cellular modification within physiological environments, avoiding cell extraction and reinfusion while preserving cellular activity and adaptability. This review summarizes recent advances in five in vivo membrane engineering strategies: bioorthogonal chemistry, genetic engineering, in vivo membrane fusion, DNA nanotechnology, and trogocytosis. Beyond summarizing recent advances, we compare their distinct strengths, limitations, and suitability for different biomedical applications, providing a framework for strategy selection. We further identify key challenges in targeting, controllability, and clinical translation. This review offers a perspective on developing more precise, controllable, and safe in vivo membrane engineering technologies.</p>","PeriodicalId":93848,"journal":{"name":"Acta biomaterialia","volume":" ","pages":""},"PeriodicalIF":9.6,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149198310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atom probe tomography shows defect-driven degradation in plasma electrolytic oxidation-coated Mg-Ca alloys.","authors":"Selase Torkornoo, Eric Woods, Yongqiang Kang, Raymond Kwesi Nutor, Qiuying Ji, Leopold Berger, Thomas Imwinkelried, Baptiste Gault","doi":"10.1016/j.actbio.2026.10.022","DOIUrl":"https://doi.org/10.1016/j.actbio.2026.10.022","url":null,"abstract":"<p><p>Magnesium alloys are promising biodegradable implant materials, but often suffer from rapid corrosion and uncontrolled hydrogen evolution in physiological environments, calling for robust surface modification strategies to regulate degradation and gas release. Plasma electrolytic oxidation (PEO) coatings are produced on an ultra-high-purity Mg-0.45 wt. % Ca alloy using two phosphate-based electrolytes and characterized by advanced electron microscopy and atom probe tomography (APT) to resolve their multi-layered structure, phase composition, and nanoscale defects. Both coatings form a tri-layered structure: a dense crystalline MgO inner barrier, a porous intermediate MgO/amorphous phosphorus-rich zone, and an outer amorphous phosphorus-rich layer modulated by electrolyte ions. APT reveals nanoscale pores, Na segregation, and H-enriched surface products after corrosion. Early-stage in vitro testing in Hank's solution shows uniform dissolution of the dense outer layer of the coating formed in the ammonia-based electrolyte, accompanied by cracking and delamination in the intermediate layer. This links the observed defects to the degradation pathways and enhanced susceptibility to localized attack within the coating. These insights reveal how electrolyte chemistry controls phase balance, porosity, and corrosion resistance, guiding the design of PEO coatings for enhanced implant longevity. STATEMENT OF SIGNIFICANCE: Understanding and controlling the degradation of Mg-based biomaterials remains a central challenge for their clinical adoption. This study establishes a nanoscale mechanistic framework linking the chemistry of plasma electrolytic oxidation (PEO) coatings to the corrosion behavior of a Mg-Ca alloy in Hank's balanced salt solution (HBSS). By combining atom probe tomography (APT) with advanced microscopy analyses, we reveal that Na accumulation within defects and the amorphous coating regions are key drivers of localized corrosion and coating instability. These insights redefine the current understanding of PEO coating performance and establish new principles for desigining degradation-resistant, clinically viable, biodegradable implants.</p>","PeriodicalId":93848,"journal":{"name":"Acta biomaterialia","volume":" ","pages":""},"PeriodicalIF":9.6,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149186949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biomanufacturing Vascular Matrix-Mimetic Hydrogels from Quantified Arterial Micromechanics and Microstructure.","authors":"Michael Scott Rafuse, David Madukwe, Meredith Overton, Richard Douglas Johnson, Wei Tan","doi":"10.1016/j.actbio.2026.10.021","DOIUrl":"https://doi.org/10.1016/j.actbio.2026.10.021","url":null,"abstract":"<p><p>The microstructural and micromechanical properties of the arterial extracellular matrix (ECM) are central to vascular cell behavior but are disrupted by disease and aging. Elastin and fibrillar collagens provide essential cues, yet the effects of disease-associated ECM remodeling on smooth muscle function remain poorly defined. Here, we imaged fibrillar ECM components across layers of healthy and hypertensive arteries in a large animal model and quantified their stiffness with submicron and piconewton resolution. These animal-derived data guided the fabrication of artery-mimetic hydrogels using image-derived 3D projection micro-stereolithography (µSTL) and thiol-ene clickable bioinks. The resulting hydrogels replicated fibril features down to 2 µm with emulated curvatures and tunable stiffness spanning physiological to pathological ranges (1-35 kPa). Systematic optimization of printing parameters, including light intensity, exposure time, monomer concentration, crosslinker type, optical configurations, and hydrogel swelling solutions, ensured high-fidelity structural replication. Vascular smooth muscle cells cultured on these hydrogels revealed that diseased ECM conditions promoted hypertrophy, impaired contractility, and reduced calcium responsiveness. Quantitative PCR showed reduced expression of contractile markers (MYH11, SMTN) and marked upregulation of PTK2 (focal adhesion kinase) on hypertensive-mimetic matrices, implicating focal adhesion-dependent mechanotransduction in this response. This image-guided biofabrication platform enables precise engineering of vascular microenvironments for mechanistic studies of remodeling, therapeutic testing, and modeling of complex vascular disease states. STATEMENT OF SIGNIFICANCE: Arterial extracellular matrix stiffens and reorganizes in hypertension, yet in vitro models rarely reproduce these micron-scale changes. We measured layer-specific stiffness and fibrillar architecture in arteries from normotensive and hypertensive steers, a large animal model with fattening-induced hypertension. These data were directly translated into projection micro-stereolithography of thiol-ene hydrogels. The resulting matrices, high-fidelity 3D hydrogel prints, reproduced fibrillar features down to 2 µm with emulated curvatures and tunable stiffness spanning 1-35 kPa. Vascular smooth muscle cells cultured on hypertensive-mimetic matrices exhibited hypertrophic morphology, reduced calcium responsiveness and agonist-induced contractility, altered contractile-marker expression, and increased PTK2 expression, linking disease-associated matrix remodeling to altered mechanotransduction. This measurement-to-fabrication workflow provides a physiologically informed platform for mechanistic studies of vascular remodeling and evaluation of therapeutic responses.</p>","PeriodicalId":93848,"journal":{"name":"Acta biomaterialia","volume":" ","pages":""},"PeriodicalIF":9.6,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149187000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tailoring the microstructure, mechanical properties, degradation behavior, and biological performance of biodegradable Zn-Cu alloys through plastic deformation processing.","authors":"Bo Deng, Haiyan Li, Wenzheng Dong, Zhilin He, Yilong Dai, Ding Li, Xian Tong, Jixing Lin, Yuncang Li, Dechuang Zhang, Cuie Wen","doi":"10.1016/j.actbio.2026.10.023","DOIUrl":"10.1016/j.actbio.2026.10.023","url":null,"abstract":"<p><p>Zn-based alloys have attracted substantial attention as next-generation biodegradable implant materials due to their intrinsic biodegradability, biocompatibility, and unique potential to facilitate tissue regeneration while providing temporary mechanical support. However, systematic studies investigating how different plastic-deformation strategies govern their microstructure and, consequently, their mechanical, corrosion, and biological performance remain scarce. Here, the effects of five plastic-deformation processes, namely, cold rolling, hot rolling, hot extrusion, hot rolling combined with asymmetric rolling, and hot extrusion combined with equal-channel angular pressing (HE+ECAP), on the microstructure, mechanical properties, degradation behavior, hemocompatibility, cytocompatibility, and antibacterial activity of a Zn-3Cu alloy were comprehensively investigated. Microstructural analysis revealed that all processed alloys consisted of an η-Zn matrix and a CuZn₅ phase. Notably, the HE+ECAP alloy demonstrated a favorable combination of mechanical, degradation, and antibacterial properties, exhibiting a yield strength of ∼303.4 MPa, ultimate tensile strength of ∼312.4 MPa, elongation of 39.1%, degradation rate of ∼33.4 μm/year after immersion in Hanks' balanced salt solution (HBSS) for 28 days, and inhibition zone diameter of ∼12.8 mm against Staphylococcus aureus. Furthermore, all processed alloys demonstrated satisfying hemocompatibility and cytocompatibility. Overall, HE+ECAP processing synergistically enhanced the comprehensive properties of the Zn-3Cu alloy, advancing its potential for biodegradable orthopedic implants. STATEMENT OF SIGNIFICANCE: This work reports the effects of five plastic-deformation processes, namely, cold rolling (CR), hot rolling (HR), hot extrusion (HE), hot rolling combined with asymmetric rolling (HR+ASR), and hot extrusion combined with equal-channel angular pressing (HE+ECAP), on the microstructure, mechanical properties, degradation behavior, hemocompatibility, cytocompatibility, and antibacterial activity of a Zn-3Cu alloy. The HE+ECAP alloy demonstrated a favorable combination of mechanical, degradation, and antibacterial properties, exhibiting a yield strength of ∼303.4 MPa, elongation of 39.1%, degradation rate of ∼33.4 μm/year, and inhibition zone diameter of ∼12.8 mm against Staphylococcus aureus. All processed alloys demonstrated satisfying hemocompatibility and cytocompatibility. Overall, HE+ECAP synergistically enhanced the comprehensive properties of the Zn-3Cu alloy, advancing its potential for biodegradable orthopedic implants.</p>","PeriodicalId":93848,"journal":{"name":"Acta biomaterialia","volume":" ","pages":""},"PeriodicalIF":9.6,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149185981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Region-dependent in vivo degradation and local repair responses of a magnesium artificial lamina in a rabbit lamina defect model.","authors":"Qichao Zhao, Jie Wang, Jun Wang, Minghui Zhao, Wenxiang Li, Delin Ma, Wancheng Li, Yijing Chen, Yuke Lu, Yujie Cai, Long Chen, Shijie Zhu, Liguo Wang, Xiaochao Wu, Shaokang Guan","doi":"10.1016/j.actbio.2026.10.020","DOIUrl":"https://doi.org/10.1016/j.actbio.2026.10.020","url":null,"abstract":"<p><p>Magnesium (Mg)-based implants are promising for lamina defect reconstruction because of their biodegradability, mechanical compatibility, and bioactivity. However, in vivo degradation is usually assessed at the whole-implant level, and it remains unclear whether distinct regions of the same implant experience different degradation-repair couplings. In this study, a ZE21C Mg alloy artificial lamina was implanted in a New Zealand rabbit lumbar lamina defect reconstruction model to evaluate region-dependent degradation and local repair responses. Finite element analysis showed higher equivalent stress and strain on the residual-bone side. SEM/EDS and micro-CT analyses demonstrated the asymmetric degradation of the same implant in vivo. The residual-bone side exhibited faster Mg degradation, more severe surface and interfacial degradation, and higher TRAP-related remodeling activity, whereas the opposite side degraded more slowly, maintained a denser interface, and exhibited better bone formation and tissue integration. At 12 weeks, the remaining implant volume was 20.2 ± 2.0% on the residual-bone side, compared with 41.9 ± 5.3% on the opposite side, demonstrating pronounced region-dependent degradation within the same implant. Transcriptomic analysis indicated that rapid degradation was accompanied by stronger bone resorption and inflammatory interface reactions. The slow degradation area is associated with a more vascularized repair microenvironment that supports the matrix. These findings indicate that accelerated regional degradation does not necessarily promote bone regeneration. Therefore, region-specific degradation control may be critical for designing biodegradable Mg implants in complex anatomical environments. STATEMENT OF SIGNIFICANCE: Biodegradable magnesium implants are generally evaluated by their average degradation rate, despite regional differences in mechanical and biological environments. In a rabbit lamina reconstruction model, we directly compared two regions of the same ZE21C magnesium artificial lamina, limiting implant- and animal-level variability. The residual-bone side experienced higher stress, faster degradation, a less stable interface, stronger osteoclast-related activity, and poorer bone formation; the opposite side degraded more slowly and supported better tissue integration. Transcriptomic analysis linked these outcomes to distinct inflammatory, bone-resorptive, vascular, and matrix-remodeling responses. Thus, faster magnesium degradation does not necessarily improve repair. This work identifies region-specific degradation control as a key design principle for biodegradable orthopedic implants in complex anatomical environments.</p>","PeriodicalId":93848,"journal":{"name":"Acta biomaterialia","volume":" ","pages":""},"PeriodicalIF":9.6,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149186008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tumor-triggered DNA fragmentation with a nucleus-targeted nanodrug for precise cGAS-STING activation and enhanced cancer immunotherapy.","authors":"Qian Shen, Mengting He, Yuan Cao, Tianshu Xu, Guo Wu, Zhe Wang, Shili Xu, Zixian Huang, Rong Li, Xiaoding Xu","doi":"10.1016/j.actbio.2026.10.019","DOIUrl":"https://doi.org/10.1016/j.actbio.2026.10.019","url":null,"abstract":"<p><p>Activation of the cGAS-STING pathway has emerged as a promising strategy in cancer immunotherapy due to the ability to trigger robust innate and adaptive immune response within the immunosuppressive tumor microenvironment. However, its clinical translation is restricted by multiple intractable challenges, particularly the severe inflammatory side effects caused by non-specific cGAS-STING activation. We herein developed a nucleus-targeted nanodrug with a unique characteristic of tumor-triggered DNA fragmentation and precise cGAS-STING activation. This nanodrug is engineered by encapsulating a protein (DNA fragmentation factor, DFF) and an agonist (procaspase-activating compound 1, PAC-1) into a nucleus-targeted nanoplatform. Using breast cancer (BCa) tumor models, we demonstrated this nanodrug could be efficiently internalized by BCa cells to achieve the cytosolic delivery of PAC-1 and nuclear delivery of DFF. Upon the activation of over-expressed procaspase-3 in BCa cells by PAC-1, the DNA degradation ability of DFF could be liberated, which could dramatically improve the cytosolic release of DNA fragments and thus enhance interferon-β (IFN-β) expression and secretion by activating the cGAS-STING pathway in BCa cells, ultimately inducing a significant inhibition of BCa tumor growth by enhancing the maturation of dendritic cells (DCs) and antitumor immunity of CD8⁺ T cells. STATEMENT OF SIGNIFICANCE: Activation of the cGAS-STING pathway has demonstrated the ability to reshape the immunosuppressive TME by triggering both the innate and adaptive immunity, but its clinical translation is restricted due to the severe inflammatory side effects caused by non-specific activation. We herein propose a concept of tumor-triggered cytosolic release of DNA fragments for precise cGAS-STING activation and enhanced cancer immunotherapy. To this end, a nanodrug is engineered by encapsulating DFF and PAC-1 into a nucleus-targeted nanoplatform. In this nanodrug, PAC-1 could induce the apoptosis of BCa cells by activating their over-expressed procaspase-3 into caspase-3, which could further trigger the DNA degradation ability of DFF to improve the cytosolic release of DNA fragments for precise cGAS-STING activation, thereby promoting IFN-β secretion from BCa cells to enhance the maturation of DCs and antitumor immunity of CD8⁺ T cells. The concept of tumor-triggered cytosolic release of DNA fragments demonstrated herein provides a potential immunotherapeutic strategy for tumor therapy, particularly the immune cold tumors with low response to immunotherapy.</p>","PeriodicalId":93848,"journal":{"name":"Acta biomaterialia","volume":" ","pages":""},"PeriodicalIF":9.6,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149186159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nanomechanics of mandible wear in insects.","authors":"Dilanka I Deegala, Jonathan G Pattrick, David Labonte","doi":"10.1016/j.actbio.2026.10.011","DOIUrl":"https://doi.org/10.1016/j.actbio.2026.10.011","url":null,"abstract":"<p><p>Many animals rely on specialised mouthparts to process food. Because this is a mechanically demanding task, mouthparts often wear, with potentially serious consequences for feeding performance and thus fitness. The biomechanics of wear are therefore of clear biological relevance, but remain poorly understood, especially in insects, where conventional engineering wear tests are hard to implement. Here, we present a nanomechanical characterisation of the mandibular epicuticle of three insect species: two leaf-cutting specialists, one with and one without transition-metal inclusions, and an omnivore. Contrary to predictions from simple engineering wear theory, wear resistance was neither directly proportional to indentation hardness nor inversely proportional to wear load. We suggest that this discrepancy arises in part from the high hardness-to-modulus ratio of mandibular epicuticle, which renders indentation hardness a poor proxy for resistance to plastic deformation. A simple elasto-plastic wear model qualitatively captures the main discrepancies between experiment and theory, and points to a revised set of wear proxies that may allow at least a qualitative ranking of biological materials via iso-performance lines on Ashby plots. Yet, as with most wear models, the wear coefficient remains unpredictable, a limitation strikingly illustrated by the increase in epicuticular wear resistance upon hydration despite a decrease in both hardness and modulus. Together, these observations suggest that purely plastic wear models may often be inadequate for biological materials with a high hardness-to-modulus ratio, and that even elasto-plastic models require careful validation against experimental wear assays. Significance statement Wear limits the functional lifespan of biological tools; however, quantifying, let alone predicting, wear in small, heterogeneous materials is often challenging. In this study, we directly measure nanoscale wear in insect mandibular cuticle and compare our findings with predictions derived from common mechanical wear models. Because of its high hardness-to- modulus ratio, insect epicuticle-like many biomaterials-exhibits an elasto-plastic mechanical response, which can be captured by extending existing approaches with a lumped-parameter elasto-plastic model. The agreement between the model and experiment reveals why using standard proxies can yield even qualitatively incorrect wear rankings and suggests updated elasto-plastic metrics for comparing wear resistance across cuticles and other polymeric biomaterials.</p>","PeriodicalId":93848,"journal":{"name":"Acta biomaterialia","volume":" ","pages":""},"PeriodicalIF":9.6,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149170447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Age-dependent brain mechanics are linked to microstructural changes.","authors":"Mayra Hoppstädter, Kevin Linka, Marion Schmicke, Ellen Kuhl, Markus Böl","doi":"10.1016/j.actbio.2026.10.010","DOIUrl":"10.1016/j.actbio.2026.10.010","url":null,"abstract":"<p><p>Accurate knowledge of brain tissue mechanics is essential for understanding the pathologies that cause mechanical changes and for developing reliable computer models for neurosurgical procedures. However, the age-related changes in brain mechanics and their microstructural basis are not fully understood. In this study, we examined age-related changes in brain mechanics and microstructure in porcine tissue across five age groups, from early development to young adulthood. Mechanical tests in tension and compression were performed in different anatomical regions, including an anisotropic characterization of the corpus callosum. We used Bayesian parameter identification to estimate material parameters based on isotropic, hyperelastic Ogden and anisotropic, hyperelastic Gasser-Ogden-Holzapfel models under the assumption of large deformations with finite strains. Histological analyses additionally quantified myelin, cell, glia, and neuron measures. Our results revealed nonlinear age dependencies of tensile and compressive mechanics accompanied by clear age-dependent microstructural differences. Notably, myelin- and glia-related measures were the most consistent positive correlates of stiffness. Further, mediation analysis suggested that microstructure, particularly glia-related features, may serve as a measurable intermediate link between age and mechanics. These findings provide a microstructurally informed basis for more realistic, age-dependent computational brain models. Statement of Significance: In order to develop realistic computational models of the brain, it is essential to understand why brain mechanics change with age. While previous work has described age-dependent mechanical behavior, the structural basis of these changes remains unclear. In this study, we combine previously published mechanical data with new, sample-specific histological measurements across development. The key innovation is the use of mediation analysis to test for a measurable statistical link between microstructural changes and mechanics while accounting for the direct effect of age. This approach provides more mechanistic insight than age-dependent mechanical characterization or simple correlation alone. It also helps identify which tissue components are most relevant for explaining developmental changes in brain mechanics.</p>","PeriodicalId":93848,"journal":{"name":"Acta biomaterialia","volume":" ","pages":""},"PeriodicalIF":9.6,"publicationDate":"2026-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149167708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to \"Gastric ulcers: Biomaterial-based strategies for tissue regeneration and future perspectives on environment-designed biomaterials\" [Acta Biomaterialia 222 (2026) 95-109].","authors":"Caio F C Souza, Inês Vilela de Sousa, Henrique Fernandes-Mendes, Ricardo Marcos-Pinto, Alvaro Mata, Helena S Azevedo, Pedro L Granja","doi":"10.1016/j.actbio.2026.09.050","DOIUrl":"https://doi.org/10.1016/j.actbio.2026.09.050","url":null,"abstract":"","PeriodicalId":93848,"journal":{"name":"Acta biomaterialia","volume":" ","pages":""},"PeriodicalIF":9.6,"publicationDate":"2026-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149168184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}