Acta Biomaterialia最新文献

{"title":"Design and fabrication of degradation resistant hydrogel optical fibers for potential long-term usage of photomedicine in deep-tissue","authors":"Jiahao Zheng ,&nbsp;Yue Yan ,&nbsp;Yifan Li ,&nbsp;Zeqi Zhang ,&nbsp;Shijia Tang ,&nbsp;Feimin Zhang ,&nbsp;Kai Hou ,&nbsp;Guoyin Chen ,&nbsp;Meifang Zhu","doi":"10.1016/j.actbio.2025.09.009","DOIUrl":"10.1016/j.actbio.2025.09.009","url":null,"abstract":"<div><div>Hydrogel optical fiber has attracted attention in the fields of photomedicine in deep-tissue due to its biocompatibility, such as soft wet nature, tissue-like modulus, and low toxicity. Owing to its distinctive optical properties and the ease of crosslinking, PEGDA is commonly employed in the fabrication of hydrogel optical fibers with high light-guiding efficiency. However, due to the hydrolysis susceptibility of ester bonds, these hydrogel optical fibers tend to degrade rapidly in physiological environments, which may compromise their long-term functionality. Additionally, the development of a light transmission device that can operate long-term, efficiently and stably in the internal environment is expected to further promote the progress of photomedicine. In this work, we introduce a degradation-resistant hydrogel optical fiber (DRHOF) with high optical transmission. In the preparation process, we replace the ester bond in the polymer molecular chain with an amide bond with higher activation energy to achieve a longer degradation period. In addition, the sheath/core structured hydrogel fiber is prepared continuously by a coaxial needle, and the refractive index (RI) of the sheath/core spinning liquid is regulated to achieve low optical attenuation (0.12 ± 0.01 dB cm⁻¹ with 650 nm laser). It has lower cytotoxicity and causes less tissue inflammation after implantation than conventional polymer fibers. In terms of mechanical properties, its Young's modulus is adjustable between 0.08 MPa ∼ 0.41 MPa, which is similar to the modulus of the soft tissue. Thus, the DRHOF demonstrates the great potential being used as a highly effective tool for application in the field of photomedicine.</div></div><div><h3>Statement of significance</h3><div>The fabricated DRHOF exhibits resistance to degradation and biocompatibility, which can maintain the structural integrity within the muscle tissue without causing severe inflammation for at least three months.</div><div>The fabricated DRHOF shows a light attenuation of 0.12 ± 0.01 dB cm⁻¹ (λ=650 nm).</div><div>After three months in a simulated human body environment, light attenuation remained at 0.156 dB cm⁻¹, showing that DRHOF is suitable for long-term photomedicine in deep tissues.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"205 ","pages":"Pages 372-381"},"PeriodicalIF":9.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145056599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nanozymes in infected wound therapy: catalytic mechanisms, rational design and combination therapy","authors":"Shuyi Xing ,&nbsp;Bingbing Liu ,&nbsp;Luning He ,&nbsp;Shuaipeng Feng ,&nbsp;Kaisheng Nan ,&nbsp;Donghua Di ,&nbsp;Yikun Gao ,&nbsp;Siling Wang ,&nbsp;Yunbo Zhao ,&nbsp;Qinfu Zhao","doi":"10.1016/j.actbio.2025.07.065","DOIUrl":"10.1016/j.actbio.2025.07.065","url":null,"abstract":"<div><div>Topics of wound healing have gained increasing attention, and wound healing is a complex dynamic process involving multiple stages and cytokines interactions. The causes of wound formation include physical injury, burns, frostbite resulting in ulcers or abscesses, and chronic diseases such as diabetes. All of these factors can lead to varying degrees of tissue damage. Infectious wound-related diseases are a major public safety concern, affecting the healthy lives of millions of people. Nanozymes, as a new artificial enzyme with the advantages of low cost and good stability, can effectively mimic natural enzyme activity and regulate the wound microenvironment to achieve the alleviation of oxidative stress, lowering of blood glucose, reconstruction of blood vessels, and promotion of infected wound healing. Therapies based on nanozymes and their related strategies have been extensively tapped in wound healing. This review explores the catalytic mechanism of nanozymes for wound treatment and their design directions, which provides readers with ideas for further research on the design of rational nanozymes. In addition, we have systematically explored their synergistic therapy. The clinical potentialities and future trials of nanozymes in boosting antimicrobial wound healing are accentuated in the final part.</div></div><div><h3>Statement of significance</h3><div>Infected wound healing remains a significant challenge in the medical field. Traditional wound treatments are confronted with issues such as antibiotic resistance and limited effectiveness in promoting tissue repair. However, nanozymes, with their unique enzyme-like catalytic activities and nanomaterial properties, have emerged as a promising alternative. Nanozymes can effectively regulate the wound microenvironment to alleviate oxidative stress and inflammation, thereby promoting the healing of infected wounds. In this article, we comprehensively and systematically summarize the latest progress in nanozyme-based wound healing therapies, as well as the strategies for improving current nanozyme-based therapeutic approaches. Moreover, we elaborate on the role of nanozymes in the treatment of infected wounds from multiple perspectives, present examples of the combination of nanozymes with various other wound healing treatment methods, and summarize nanozyme-based delivery systems.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"205 ","pages":"Pages 1-25"},"PeriodicalIF":9.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144791028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A viral infection-biomimetic strategy for antibody-guided targeted protein degradation","authors":"Yuanyuan Yang ,&nbsp;Chuanda Zhu ,&nbsp;Xiaojun Wang ,&nbsp;Lidong Gong ,&nbsp;Qiang Ma ,&nbsp;Yujie Luo ,&nbsp;Hongjun Wang ,&nbsp;Dan Lu ,&nbsp;Ridong Li ,&nbsp;Qiang Zhang ,&nbsp;Fen Gu ,&nbsp;Zhiqiang Lin","doi":"10.1016/j.actbio.2025.08.030","DOIUrl":"10.1016/j.actbio.2025.08.030","url":null,"abstract":"<div><div>Targeted protein degradation (TPD) is a valuable strategy for investigating protein functionality in cell biology and drug discovery. Among the various emerging TPD technologies, antibody-guided TPD offers key advantages over other protein degradation methods in terms of compatibility with different proteins of interest (POIs) and cell types. However, increasing the efficiency of cellular antibody internalisation and protein degradation remains challenges. Inspired by viral infection, which often efficiently activates protein degradation pathways in host cells, we developed a strategy called virus infection-mimicking targeted protein degradation (ViTPD) as a universal platform for degrading intracellular proteins. By mimicking three features of viral infection, we produced ViTPD nanoparticles by biomineralising antibodies enveloped by viral membranes or mixed with IFN-α. The biomineralised shell enhanced the cellular uptake of ViTPD nanoparticles via clathrin-mediated endocytosis. Similar to viral neutralising antibodies entering cells, the Fab region of the antibody released from ViTPD nanoparticles binds the POI, while the Fc region can recruit TRIM21, a key enzyme that continuously consumes during protein degradation. Interestingly, viral membrane components or IFN-α in the ViTPD led to increased TRIM21 expression, which enhanced the efficiency of proteolysis. ViTPD can effectively degrade several POIs, including GFP, FAK, COPZ1 and TREX1. Collectively, our results demonstrate that ViTPD provides a novel design strategy and an efficient nanoplatform for targeting intracellular protein degradation.</div></div><div><h3>Statement of significance</h3><div>Antibody-guided targeted protein degradation (TPD) exhibits superior versatility compared to conventional degradation methods, demonstrating broad compatibility with diverse proteins of interest (POIs) across various cell types. Despite these advantages, significant challenges persist in optimizing cellular antibody internalization efficiency and degradation kinetics. In this study, we developed ViTPD, a biomimetic TPD platform that mimicking three viral infection features: (1) virus-like cellular internalization pathways, (2) virus-neutralizing antibody behavior, and (3) host-mediated protein degradation responses during viral infection. The development of ViTPD provides not only a robust platform for degrading diverse intracellular POIs but also establishes new design principles for next-generation protein degradation systems. This platform establishes new design principles for next-generation TPD systems while expanding therapeutic potential for precision medicine.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"205 ","pages":"Pages 659-671"},"PeriodicalIF":9.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144982074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A biphasic microstructural model of skeletal muscle to study structure-function mechanisms under multiaxial tensile and compressive conditions","authors":"Benjamin B. Wheatley ,&nbsp;Minhaj U. Bhuiyan ,&nbsp;Sabrina S. Lorza ,&nbsp;Kevin M. Moerman ,&nbsp;Pierre-Yves Rohan","doi":"10.1016/j.actbio.2025.08.049","DOIUrl":"10.1016/j.actbio.2025.08.049","url":null,"abstract":"<div><div>The passive material properties of skeletal muscle are key to proper force transmission, and changes to muscle microstructure can have deleterious effects on whole tissue function. However, to the best of the authors’ knowledge, it is not currently possible to predict the passive material properties of skeletal muscle with microstructural measurements such as titin isoform type and/or extracellular matrix collagen content, type, or organization. The goals of this work were to 1) develop an experimental dataset at the tissue length scale of passive skeletal muscle under multiaxial loading conditions, 2) develop a biphasic microstructural model of skeletal muscle, and 3) calibrate, validate, and implement such a model. Experimental planar biaxial and semi-confined compression experiments, with intramuscular pressure measurements, were conducted. A microstructural finite element model was developed using the GIBBON toolbox based on a Voronoi-like structure and a multi-domain biphasic, anisotropic, hyper-viscoelastic constitutive approach was used to model muscle fibers and the extracellular matrix. Following model calibration and validation to experimental data (with root mean square error values ranging from 0.5 % - 21 %), a parametric study suggested that tensile properties of the muscle fibers and extracellular matrix affected anisotropic tensile stress-stretch behavior to the greatest extent, while permeability greatly affected compressive stress-stretch behavior. Some parameters, such as extracellular matrix volume fraction and muscle fiber bulk modulus, affected both tensile and compressive stress-stretch behavior. Future work to expand this model into specific impairment conditions or to simulations of whole muscle would be a benefit to the field.</div></div><div><h3>Statement of significance</h3><div>Skeletal muscle is the primary driver of human locomotion. To better understand how healthy and impaired muscle functions towards the prevention of muscle-related impairments, we can use computational modeling. In this study, we developed a new model of the microstructure of muscle tissue that incorporates fluid, which is typically neglected in computer models of muscle tissue. Collectively, the work suggests that interactions between different tissue components, specifically muscle cells, the extracellular matrix, and fluid can collectively contribute to the mechanical behavior of muscle tissue. Our results can be used to build better computer models of muscle tissue and study specific mechanisms – such as fluid flow in muscle tissue – as ways to prevent muscle injuries such as a pressure ulcer.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"205 ","pages":"Pages 491-504"},"PeriodicalIF":9.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144982091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structuring of gellan hydrogel enables the production of inherently antifibrotic, lubricating eye drops","authors":"Samuel R. Moxon ,&nbsp;Rachel C. Vincent ,&nbsp;A. Taylor ,&nbsp;B. Cassidy ,&nbsp;Richard J.A. Moakes ,&nbsp;Gibran F. Butt ,&nbsp;Graham R. Wallace ,&nbsp;Anthony D. Metcalfe ,&nbsp;Richard L. Williams ,&nbsp;Nicholas M. Barnes ,&nbsp;Ann Logan ,&nbsp;Saaeha Rauz ,&nbsp;Liam M. Grover","doi":"10.1016/j.actbio.2025.08.039","DOIUrl":"10.1016/j.actbio.2025.08.039","url":null,"abstract":"<div><div>Gellan is an anionic polysaccharide that forms optically clear hydrogels, making it suitable for use in ocular applications. Previous research has demonstrated that gellan fluid gels, when used alongside standard treatments (antibiotics and corticosteroid eye drops), reduce corneal scarring in models of microbial keratitis. This study investigated the potential mechanisms behind the enhanced corneal healing observed with drug-free gellan fluid gels. The impact of varying formulation parameters, such as polymer concentration and applied shear rate, on the physical properties of the fluid gels, including viscosity, stiffness, and lubricity, was examined to optimise gellan fluid gels for use as therapeutic eye drops. Biological analyses were undertaken that highlighted the capacity of gellan fluid gels to provide corneal cells with effective lubrication preventing cell removal on the application of shear. Additionally, gellan fluid gels were shown to sequester TGFβ1, a pro-fibrotic cytokine. Sequestration of the TGFβ1 resulted from electrostatic interactions between the negatively charged gellan and positively charged TGFβ1. As a consequence of this, gellan fluid gels inhibit TGFβ1-induced pro-fibrotic gene expression in corneal fibroblasts, contributing to reduced scarring and improved wound healing. The results suggest that gellan fluid gels, through modulation of physical properties and biological interactions, offer a mechanism for promoting ocular healing and mitigating inflammation-induced scarring, even in the absence of pharmaceutical actives.</div></div><div><h3>Statement of significance</h3><div>This study presents the development of gellan fluid gel eye drops designed to prevent ocular fibrosis after damage. The formulation achieved lubricity comparable to commercial eye drops but with significantly enhanced viscosity and superior capacity to shield cells from damaging shear forces. By optimising gellan concentration and fabrication parameters, the eye drops exhibited reduced ocular friction and improved therapeutic efficacy. Additionally, the fluid gels sequestered TGFβ1, a key fibrosis molecule, with higher gellan concentrations showing enhanced absorption. Importantly, the formulations maintained ease of application through droppers, making them practical for daily use. This work highlights a cost-effective and patient-friendly solution, advancing biomaterial-based therapies for ocular therapies.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"205 ","pages":"Pages 260-269"},"PeriodicalIF":9.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144982118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Is Tattooing an Injection? Evaluating the Mechanics of Ink Placement","authors":"Sasha Noble ,&nbsp;Kelli Moseman ,&nbsp;Selina Medina ,&nbsp;Guy K. German ,&nbsp;John Swierk","doi":"10.1016/j.actbio.2025.08.055","DOIUrl":"10.1016/j.actbio.2025.08.055","url":null,"abstract":"<div><div>Guidance recently released by the Food and Drug Administration (FDA) regarding tattoo inks describes tattooing as an injection process, but is injection the correct terminology to use when describing tattooing? This perspective aims to provide a brief overview of the core mechanics and science behind injection and tattoo processes, as well as emphasize the importance of using the correct terminology when referencing tattoos and the act of tattooing moving forward.</div></div><div><h3>Statement of significance</h3><div>Due to a change in the FDA regulatory framework around cosmetics in December 2022, for the first time the FDA is in the process of actively regulating tattoo inks. Central to how tattoos will be regulated is whether tattoos and tattooing should be considered an injectable process. If tattoos are injectables, then tattoo inks would be considered within a medical device framework leading to a radical alteration tattoo industry in the US and globally. This perspective surveys the literature to understand what it means for something to be “injected” and then compares that to the state-of-the-art understanding about how tattoos are deposited in the skin. Based on this analysis, it is clear that tattooing should not be described as an injection process.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"205 ","pages":"Pages 26-33"},"PeriodicalIF":9.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144982129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of scaffold material choice on osteosarcoma phenotype and drug responses in 3D","authors":"Callan E. Monette ,&nbsp;Jeehee Lee ,&nbsp;Abena Peasah ,&nbsp;Leanne C. Sayles ,&nbsp;Michelle Tai ,&nbsp;E. Alejandro Sweet-Cordero ,&nbsp;Fan Yang","doi":"10.1016/j.actbio.2025.08.046","DOIUrl":"10.1016/j.actbio.2025.08.046","url":null,"abstract":"<div><div>Biomaterials-based 3D models have emerged as new cancer research tools for studying osteosarcoma (OS). However, the impact of scaffold material choice on OS phenotype and drug responses in 3D remains largely unknown, as previous studies used different biomaterials as scaffolds without direct comparison. In this study, we systematically compared four biomaterials: Gelatin methacrylate (GelMA), Gelatin microribbons (Gel µRB), Collagen I hydrogel (Col1), and Poly(DL-lactide-co-glycolide) (PLGA). All have previously been applied for either 3D OS culture or bone tissue engineering. To mimic the mineral component of bone, hydroxyapatite mineral nanoparticles (HAnp) were incorporated into all scaffolds. We assessed key clinically relevant OS phenotypes including cell proliferation, extracellular matrix (ECM) deposition, and responses to multiple chemotherapeutic agents. Our results demonstrate that scaffold material significantly influences OS phenotype and drug resistance. Notably, PLGA results in the lowest cell proliferation, GelMA promotes drug resistance and tumor ECM deposition, and Gel µRB better mimics OS signaling of orthotopic tumor xenografts <em>in vivo.</em> The findings from this comparative study underscore the impact of scaffold choice on OS phenotype and drug response. It also provides valuable insights for guiding the selection of appropriate scaffold materials to better mimic the desirable OS phenotype to advance OS therapeutic discovery.</div></div><div><h3>Statement of significance</h3><div>Osteosarcoma (OS), a highly aggressive bone cancer, has seen a stagnant survival rate for over three decades. This study addresses a critical knowledge gap by comparing four widely used bone tissue engineering scaffolds for 3D OS culture. Unlike previous studies, this work provides a comprehensive analysis of how scaffold choice influences OS proliferation, signaling, extracellular matrix deposition, and drug resistance. These findings underscore the critical role of biomaterials choice in modulating OS behavior and will guide the choice of 3D scaffolds for more effective OS disease modeling and improving therapeutic discovery.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"205 ","pages":"Pages 164-175"},"PeriodicalIF":9.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144981998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A hydrogel tissue adhesive incorporating basic fibroblast growth factor-loaded liposomes accelerates cutaneous wound healing by enhancing cell proliferation, collagen synthesis and angiogenesis","authors":"Yujia Geng ,&nbsp;Yang Gao ,&nbsp;Desheng Qi ,&nbsp;Zhen Wang ,&nbsp;Zheng Zou ,&nbsp;Zhiyun Zhang ,&nbsp;Jiaqi Lian ,&nbsp;Zhen Zhang ,&nbsp;Chaoliang He ,&nbsp;Ying Shao","doi":"10.1016/j.actbio.2025.08.035","DOIUrl":"10.1016/j.actbio.2025.08.035","url":null,"abstract":"<div><div>Tissue adhesives have become substitutes or adjuvants for surgical sutures owing to their minimal tissue damage and ease of application. However, limitations remain for existing tissue adhesives, such as weak adhesion strength, potential toxicity, and lack of bioactivities to promote wound healing. Here, we developed an injectable and biocompatible hydrogel tissue adhesive incorporating basic fibroblast growth factor (bFGF)-loaded liposomes for sutureless wound closure and promoting wound healing. The hydrogel, formed by 10 %(w/v) human serum albumin (HSA) and o-phthalaldehyde (OPA)-functionalized four-arm poly(ethylene glycol) (4aPEG-OPA) through irreversible OPA/amine condensation reaction, demonstrated strong tissue adhesion properties, biodegradability (complete degradation in PBS containing 1 U/mL elastase within 10 days), and biocompatibility. The hydrogel incorporating bFGF-loaded liposomes achieved sustained release of bFGF (cumulative release ratio of 65.4 % over 8 days), and promoted cell proliferation, migration, collagen production, and angiogenesis. In rat and porcine full-thickness skin incision models, the hydrogel effectively closed the wounds and facilitated wound healing within 14 days, outperforming commercially available fibrin glue and cyanoacrylate adhesives. RNA sequencing and western blotting analysis demonstrated that the hydrogel stimulated cell proliferation, collagen production, and angiogenesis. Overall, this hydrogel tissue adhesive shows great potential for encouraging wound closure without suture and promoting wound healing.</div></div><div><h3>Statement of significance</h3><div>This study introduces a multifunctional tissue-adhesive hydrogel formed by covalent cross-linking of human serum albumin with o-phthalaldehyde (OPA)-terminated four-arm poly(ethylene glycol), and incorporated with bFGF-loaded liposomes. The catalyst-free OPA/amine reaction used in its synthesis ensures a mild and controllable gelation process, which is beneficial for maintaining the bioactivity of encapsulated growth factors. This composite system exhibited sustained growth factor release profile and remarkable bioactivity in regulating skin cell behaviors, which facilitates easier clinical translation compared to existing approaches. In rat and porcine models, it achieved sutureless wound healing and outperformed commercial adhesives in promoting re-epithelialization and angiogenesis, offering a promising alternative to traditional sutures and commercial adhesives.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"205 ","pages":"Pages 242-259"},"PeriodicalIF":9.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144982051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Label-free structural and mechanical characterization of rat uterosacral ligaments","authors":"Joseph Thomas ,&nbsp;Kandace Donaldson ,&nbsp;Clara Gimenez ,&nbsp;Monique Vaughan ,&nbsp;Yizheng Zhu ,&nbsp;Raffaella De Vita","doi":"10.1016/j.actbio.2025.08.009","DOIUrl":"10.1016/j.actbio.2025.08.009","url":null,"abstract":"<div><div>This study presents quantitative applications of label-free imaging methods to characterize the structure of the uterosacral ligaments (USLs) before, during, and after loading. Rat USLs (<span><math><mrow><mi>n</mi><mo>=</mo><mn>14</mn></mrow></math></span>) were excised with their spinal and cervical attachments, clamped at these attachment sites, and pulled uniaxially in a custom-built tensile testing machine along their main <em>in vivo</em> loading direction. During uniaxial testing, optical coherence tomography (OCT) images were recorded, revealing the re-arrangement and failure of the structural components of the USLs. Before and after uniaxial testing, second harmonic generation (SHG) microscopy was also used to image collagen and smooth muscle within the proximal, intermediate, and distal regions of the USLs. From the OCT images, two metrics, the global depth variation (GDV) and the bundle energy projection (BEP), were extracted to quantify morphological changes as a function of the applied load and displacement. The GDV metric measured the heterogeneity of the USLs, while the BEP metric quantified the re-orientation of fiber bundles under uniaxial testing. SHG images showed that the rat USLs have a complex microstructure with wavy collagen fibers interwoven with smooth muscle bundles. These findings on the structure-function relationship of USLs may have implications for developing non-invasive, label-free imaging modalities suitable for diagnosing conditions such as pelvic organ prolapse (POP) by evaluating the structural integrity of USLs.</div><div>Statement of Significance:</div><div>The uterosacral ligaments (USLs), often compromised in pelvic organ prolapse (POP), are the primary support to the uterus and vagina, yet surgeries to restore their function frequently have poor outcomes. Non-invasive diagnostic tools are needed to assess the integrity of the USLs for treatment planning and monitoring. This study examines how the morphology of the USLs changes under mechanical loading, using optical coherence tomography (OCT) for detailed three-dimensional imaging and quantitative optical parameters that correlate morphology with load. Complementary second harmonic generation (SHG) microscopy reveals the organization of smooth muscle and collagen within the tissue structure. These label-free imaging techniques may enable the real-time, noninvasive assessment of tissue integrity and hold potential for future applications in improving the diagnosis and treatment of POP.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"205 ","pages":"Pages 405-418"},"PeriodicalIF":9.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144982089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improvement of dentin bonding via adhesive monomers with multiple hydrogen bonding moieties","authors":"Denghao Fu ,&nbsp;Jonathan Hardy ,&nbsp;Caroline R. Szczepanski","doi":"10.1016/j.actbio.2025.08.052","DOIUrl":"10.1016/j.actbio.2025.08.052","url":null,"abstract":"<div><div>Despite advancements in bonding techniques, the resin-dentin interface remains the weakest point in dental restorations, susceptible to collagen degradation and methacrylate hydrolysis. One strategy to enhance the resin-dentin interface is to incorporate hydrogen-bonding-rich functional groups into dental adhesive resins, such as 2-ureido-4[1H]-pyrimidinone (UPy). These hydrogen bonds may bridge the adhesive resin and dentin substrate, which contains collagen and hydroxyapatite, as well as form non-covalent crosslinks within the resin. Here, we utilize UPy-functionalized methacrylamides modified with glycol spacers to ensure compatibility with other monomers commonly used in adhesive resins, as well as to promote hydrogen bonding at the resin-dentin interface and within the bulk resin. Three UPy-based methacrylamides: UPy-OPG400-MMA, UPy-OPG230-MMA and UPy-OEG148-MMA were synthesized and incorporated into model methacrylate-based adhesive formulations. Results show that the UPy-methacrylamides enhance polymerization kinetics, biocompatibility, and mechanical performance. However, these improvements and the efficacy of hydrogen-bond formation depend on the flexibility of the glycol spacers. Specifically, resins containing UPy-OPG230-MMA have the most robust hydrogen bonding in aqueous conditions, making them the optimal choice in this study. This selection is further confirmed by micro-tensile bonding strength (<span><math><mi>μ</mi></math></span>TBS) analysis and interfacial characterizations, which shows a significant enhancement in bonding performance when 50 wt% of 2-hydroxyethyl methacrylate (HEMA) is replaced with UPy-OPG230-MMA in a model self-etch adhesive. Overall, this work presents a strategy to enhance dental adhesive performance by incorporating hydrogen-bonding motifs that reinforce both the polymer network and the resin-dentin interface, offering improved durability under clinically relevant conditions.</div><div><em>Statement of Significance:</em></div><div>This study shows that hydrogen bonding interactions improve the overall performance of dental adhesives. Adhesive monomers with the 2-ureido-4[1H]-pyrmidinone (UPy) group facilitate significant hydrogen bonding interactions both within the adhesive as well as between the adhesive and an external substrate (here, dentin). This results in improved mechanical integrity of the adhesive (e.g. strength and integrity of the bonding) and impacts critical biomaterial properties such as biocompatibility. This work is significant as prior demonstrations utilizing UPy functionalities for enhanced adhesion require organic solvents (e.g. DMSO) that are incompatible with in situ, dental materials applications. Here we synthesize UPy-functionalized monomers that are miscible in aqueous solvents (water, ethanol) and compatible with comonomers used in dental materials applications.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"205 ","pages":"Pages 705-722"},"PeriodicalIF":9.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145002159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}