Acta Biomaterialia最新文献

{"title":"Wet adhesives for hard tissues","authors":"Sibei Tao ,&nbsp;Siying Tao ,&nbsp;Jiaojiao Yang ,&nbsp;Ping Fu ,&nbsp;Jianshu Li ,&nbsp;Jiyao Li","doi":"10.1016/j.actbio.2025.01.032","DOIUrl":"10.1016/j.actbio.2025.01.032","url":null,"abstract":"<div><div>The development of wet adhesives capable of bonding in aqueous environments, particularly for hard tissues such as bone, tooth, and cartilage, remains a significant challenge in material chemistry and biomedical research. Currently available hard tissue adhesives in clinical practice lack well-defined wet adhesion properties. Nature offers valuable inspiration through the adhesive mechanisms of marine organisms, advancing the design of bioinspired wet adhesives. Beyond biomimetic approaches, alternative strategies have emerged for the design of wet adhesives. This review systematically summarizes the current design strategies for wet adhesives, focusing on their applications to hard tissues. Then, the unique chemical, physical, mechanical, and biological requirements for wet adhesives applied to hard tissues are also discussed. The importance of understanding natural adhesion mechanisms and the need for high-performance materials that can meet the complex demands of hard tissue adhesion in a complex and delicate physiological microenvironment are highlighted. Finally, this review clarifies the future research directions that can further facilitate the clinical application of wet adhesives for hard tissues.</div></div><div><h3>Statement of significance</h3><div>The significance of this review lies in its comprehensive analysis of wet adhesives for hard tissues, a field that has been largely overlooked despite its critical importance in biomedical applications. The insights gained from studying natural adhesives and the translation of these mechanisms into synthetic materials have the potential to revolutionize medical procedures involving hard tissue repair and regeneration. This review meticulously addresses the distinct challenges and specific requirements of hard tissue adhesives, providing an exhaustive roadmap for researchers striving to develop wet adhesives that can endure the demanding physiological conditions inside the human body. In doing so, it aims to facilitate the transition from laboratory findings to practical clinical applications.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"194 ","pages":"Pages 1-19"},"PeriodicalIF":9.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143043888","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":"Autophagy-targeted therapy for pulmonary inflammation by 2D MX2 (M = W, Nb; X = S, Se) nanosheets","authors":"Xiaofei Zhou ,&nbsp;Ning Zang ,&nbsp;Ting Yang ,&nbsp;Jimei Jia ,&nbsp;Hongyu Zhou ,&nbsp;Jianbo Jia","doi":"10.1016/j.actbio.2025.01.045","DOIUrl":"10.1016/j.actbio.2025.01.045","url":null,"abstract":"<div><div>For biomedical applications, two-dimensional transition metal dichalcogenides (2D TMDCs) are often combined with other elements or functionalized with specific surface ligands, while their intrinsic biological activities are not yet fully understood. This study investigates the anti-inflammatory potential of four unmodified 2D TMDCs, including WS₂, WSe₂, NbS₂, and NbSe₂ nanosheets, in LPS-activated MH-S cells <em>in vitro</em> and in a mouse model of pulmonary inflammation <em>in vivo</em>. Despite their varying compositions, these 2D TMDCs exhibited comparable anti-inflammatory effects in LPS-activated MH-S cells. Notably, the 2D TMDC nanosheets disrupted autophagic signaling pathways by adhering to the cell membrane and/or being internalized by the cells, thereby enhancing cellular autophagy and reducing the LPS-induced pro-inflammatory response by inhibiting NFκB phosphorylation. Their natural affinity for lung tissue makes these 2D TMDCs promising therapeutic agents for pulmonary inflammation, a finding further supported by results from the LPS-induced mouse model. Importantly, these results highlight the critical role of composition in the effects of 2D TMDCs on autophagic signaling, which could significantly advance the development of personalized therapies for pulmonary inflammation.</div></div><div><h3>Statement of significance</h3><div>Autophagy represents a promising target for therapeutic intervention in inflammatory lung diseases. This study explores various pristine two-dimensional transition metal dichalcogenides (2D TMDCs) as regulators of autophagy for targeted therapy in pulmonary inflammation. It emphasizes the crucial role of composition in shaping the effects of 2D TMDCs on autophagic signaling, thereby advancing the development of personalized therapies for pulmonary inflammation.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"194 ","pages":"Pages 455-466"},"PeriodicalIF":9.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143049068","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":"Cu-Mn nanocomposite for enhanced tumor cuproptosis achieved by remodeling the tumor microenvironment and activating the antitumor immunogenic responses","authors":"Mengke Fan ,&nbsp;Pan Yang ,&nbsp;Linlin Huo ,&nbsp;Jianfeng Bao ,&nbsp;Mingya Tan ,&nbsp;Jie Zeng ,&nbsp;Shiqi Zhu ,&nbsp;Meiling Liu ,&nbsp;Jiayi Zhao ,&nbsp;Wenjun Miao ,&nbsp;Zhenghuan Zhao","doi":"10.1016/j.actbio.2025.01.044","DOIUrl":"10.1016/j.actbio.2025.01.044","url":null,"abstract":"<div><div>Cuproptosis is a newly discovered mode of cell death, which is caused by excess copper and results in cell death via the mitochondrial pathway. However, the complex tumor microenvironment (TME) is characterized by many factors, including high levels of glutathione and lack O₂, limit the application of traditional cuproptosis agents in antitumor therapy. Herein, we report a hyaluronic acid modified copper-manganese composite nanomedicine (CMCNs@HA) to remodel the TME and facilitate efficient cuproptosis in tumor. The integration of CuO₂ and MnO₂ into CMCNs@HA endows this nanoplatform to generate O₂ and deplete GSH in tumor site, ensuring the environment is beneficial to the cuproptosis of tumor. The glutathione (GSH) depletion process is accompanied by the release of Mn²⁺ ions. The released Mn²⁺ ions improve the cuproptosis through efficient chemodynamic therapy and initiate immune response via activating the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway, which significantly suppresses tumor growth and inhibits tumor metastases. In addition, the Mn²⁺ ions release process enables this nanoplatform to work as activable <em>T</em>₁ contrast agent to achieve accurate tumor diagnosis. This functionally complementary composite metal nanomaterial may provide effective ideas regarding the application of cuproptosis in designing tumor therapeutic regimens.</div></div><div><h3>Statement of significance</h3><div>Cuproptosis in combination with cGAS-STING offers significant potential for tumor treatment. Here, we constructed TME responsive copper-manganese composite nanomaterials (CMCNs@HA) to augment tumor cuproptosis. GSH depletion, hypoxia relief, and effective chemodynamic therapy caused by CMCNs@HA facilitate the progression of cuproptosis. Besides, CMCNs@HA successfully initiate immune response via activating the cyclic GMP-AMP synthase-stimulator of interferon genes pathway and significantly inhibits tumor metastases. Simultaneously, released Mn²⁺ ions provide real-time magnetic resonance imaging (MRI) signal changes, enabling accurate tumor diagnosis and monitoring of the therapeutic process.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"194 ","pages":"Pages 385-395"},"PeriodicalIF":9.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143054652","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":"Design and advances in antioxidant hydrogels for ROS-induced oxidative disease","authors":"Yi Xia ,&nbsp;Xinyi Li ,&nbsp;Fan Huang,&nbsp;Yuanhao Wu,&nbsp;Jinjian Liu,&nbsp;Jianfeng Liu","doi":"10.1016/j.actbio.2025.01.057","DOIUrl":"10.1016/j.actbio.2025.01.057","url":null,"abstract":"<div><div>Reactive oxygen species (ROS) play a crucial role in human physiological processes, but oxidative stress caused by excessive ROS may lead to a variety of acute and chronic diseases. Despite the development of various strategies and biomaterials, an efficiently and broadly applied method for treatment of ROS-induced oxidative disease remains a bottleneck. Aiming to improve the local oxidative stress environment, numerous bioactive hydrogels with antioxidant properties have emerged and are proven to quickly and continuously eliminate excessive ROS. To deeply understand the design principles and applications of antioxidant hydrogels is highly beneficial for designing antioxidant hydrogels for treatment of oxidative disease. This review provides a detailed summary of recent advances in design and applications of antioxidant hydrogels for various ROS-induced oxidative diseases. In this review, the kinds of antioxidant components in antioxidant hydrogels are outlined in detail. Additionally, the crosslinking methods and the biomedical applications of antioxidant hydrogels are widely summarized and discussed, especially focusing on their usage in different types of diseases and the attention given to the treatment of diseases such as skin wounds, myocardial infarction, and osteoarthritis. Finally, the future development direction of antioxidant hydrogel is further proposed.</div></div><div><h3>Statement of significance</h3><div>Oxidative stress is a pivotal biochemical process that plays a critical role in cellular homeostasis. Excessive cellular oxidative stress triggers an inflammatory response, which is implicated in a spectrum of associated diseases. Given the critical need for managing oxidative stress, antioxidant therapies have become a vital focus in medical research. Hydrogels have garnered substantial interest among biomaterial scientists due to their hydrophilic nature and biocompatibility. The review delves into the realm of antioxidant hydrogels, encompassing the classification of antioxidant components, the synthesis and fabrication of hydrogels, and a comprehensive overview of the biological applications and challenges of these antioxidant hydrogels. Aiming to provide new perspectives for researchers in developing cutting-edge therapeutic approaches that leverage antioxidant hydrogels.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"194 ","pages":"Pages 80-97"},"PeriodicalIF":9.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143124182","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":"Microenvironment-induced programmable nanotherapeutics restore mitochondrial dysfunction for the amelioration of non-alcoholic fatty liver disease","authors":"Jun Zhang ,&nbsp;Wenyi Yang ,&nbsp;Yue Zhu ,&nbsp;Zhanbin Li ,&nbsp;Yin Zheng ,&nbsp;Yufei Zhang ,&nbsp;Weisong Gao ,&nbsp;Xinge Zhang ,&nbsp;Zhongming Wu ,&nbsp;Ling Gao","doi":"10.1016/j.actbio.2025.01.019","DOIUrl":"10.1016/j.actbio.2025.01.019","url":null,"abstract":"<div><div>Nonalcoholic fatty liver disease (NAFLD) is a metabolic liver disorder with severe complications. Mitochondrial dysfunction due to over-opening of the mitochondrial permeability transition pore (mPTP) in liver cells plays a central role in the development and progression of NAFLD. Restoring mitochondrial function is a promising strategy for NAFLD therapy. Herein, we designed and developed a microenvironment-induced programmable nanotherapeutic to restore mitochondrial function and ameliorate NAFLD. cyclosporine (Cyclosporine capsules) A (CsA), as a highly effective inhibitors of the opening of mPTP, was chosen in the present work. Nanotherapeutics were prepared by assembling two structurally simple multifunctional glucosamine derivatives: dextran-grafted galactose (Dex-Gal) and Dex-triphenylphosphine (Dex-TPP). Galactose units in the nanotherapeutics guide the hepatocyte-specific uptake. Detachment of galactose from acidic lysosomes via Schiff base cleavage exposes the TPP moieties, which subsequently steers the nanotherapeutics to escape from lysosomes and target mitochondria through an enhanced positive charge, enabling precise <em>in situ</em> drug delivery. Simultaneously, the nanotherapeutics improved mitochondrial dysfunction by inhibiting palmitic acid-induced opening of the mitochondrial permeability transition pore in HepG2 cells, maintaining mitochondrial membrane potential, and decreasing reactive oxygen species production. Furthermore, CsA@Dex-Gal/TPP accumulated in the livers of NAFLD mice, restored mitochondrial autophagy, regulated abnormalities in glucose and lipid metabolism, and improved hepatic lipid deposition. This study offers a new cascading strategy for targeting liver cell mitochondria to treat NAFLD and other mitochondria-associated diseases.</div></div><div><h3>Statement of Significance</h3><div>We design microenvironment-induced programmable nanotherapeutics for NAFLD</div><div>Nanotherapeutics has the capabilities of lysosomal escape and mitochondrial targeting</div><div>Nanotherapeutics improves mitochondrial dysfunction and ameliorates NAFLD</div><div>This study offers a new cascading strategy for other mitochondria-associated diseases</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"194 ","pages":"Pages 323-335"},"PeriodicalIF":9.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142980976","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":"Phenylboronic acid-modified carbon dot-proteinase K nanohybrids for enhanced photodynamic therapy against bacterial biofilm infections","authors":"Haoyi Sun ,&nbsp;Shan Sun ,&nbsp;Henggang Wang ,&nbsp;Ke Cheng ,&nbsp;Yonghua Zhou ,&nbsp;Xinxin Wang ,&nbsp;Shang Gao ,&nbsp;Jinhong Mo ,&nbsp;Si Li ,&nbsp;Hengwei Lin ,&nbsp;Peng Wang","doi":"10.1016/j.actbio.2025.01.030","DOIUrl":"10.1016/j.actbio.2025.01.030","url":null,"abstract":"<div><div>Nanohybrids combining phenylboronic acid-modified carbon dots (PCDs) and proteinase K have been engineered for addressing the formidable challenges of antimicrobial photodynamic therapy (aPDT) against bacterial biofilm infections, overcoming biofilm barrier obstruction, the limited diffusion of reactive oxygen species (ROS), and the inadequate ROS generation of traditional photosensitizers. PCDs are formulated for superior water solubility and robust singlet oxygen (¹O₂) production, mitigating issues related to dispersion and aggregation-induced quenching typical of conventional photosensitizers. The conjugation of phenylboronic acid to CDs not only enhanced ¹O₂ generation through increased electron-hole separation but also imparted strong bacterial binding capabilities to the PCDs, enabling broad-spectrum sterilization by maximizing the ROS-mediated bacterial destruction. Proteinase K, serving as a structural “glue”, actively breaks down biofilms and facilitates the deep penetration of functional PCDs, aiding effective treatment of biofilm infections. <em>In vivo</em> studies confirm that PCDs-proteinase K nanohybrids dramatically accelerate healing in biofilm-infected wounds by synergizing enhanced photosensitization, potent bacterial adherence, and efficient biofilm elimination and penetration. This approach highlights a straightforward strategy to significantly advance aPDT, promoting the clinical adoption of non-antibiotic methods for combating bacterial biofilm infections.</div></div><div><h3>Statement of significance</h3><div>1) Phenylboronic acid-modified carbon dots (PCDs) were designed for enhanced water solubility and efficient singlet oxygen generation through surface modulation, also suggesting that surface modification can improve the inherent photosensitizing activity of CDs by promoting electron-hole separation; 2) The conjugation of phenylboronic acid endowed PCDs with strong bacterial binding capabilities, enabling highly efficient and broad-spectrum sterilization by maximizing reactive oxygen species-mediated bacterial destruction; 3) Incorporation of proteinase K (PK) leveraged its specific extracellular polymeric substance degrading capability, along with the stimuli-responsive release of PCDs from the PCDs-PK nanohybrids, facilitating biofilm breakdown and enabling deeper penetration of PCDs, thereby improving the treatment of biofilm infections</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"194 ","pages":"Pages 352-363"},"PeriodicalIF":9.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143029772","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":"Mechanical properties, degradation action, and biocompatibility of in situ nanoparticle-reinforced MgxZny/Zn composite prepared via roll bonding","authors":"Jianguo Lin ,&nbsp;Yingzhong Chen ,&nbsp;Yilong Dai ,&nbsp;Xiaokai Zhang ,&nbsp;Dechuang Zhang ,&nbsp;Yuncang Li ,&nbsp;Cuie Wen","doi":"10.1016/j.actbio.2025.01.048","DOIUrl":"10.1016/j.actbio.2025.01.048","url":null,"abstract":"<div><div>Zinc (Zn)-based alloys and composites are anticipated to emerge as a category of degradable metallic biomaterials with exceptional prospects for bone-implant applications owing to their superior biocompatibility and biofunctionality. Unfortunately, the limited strength of Zn alloys in their as-cast state restricts their use in clinical applications. In this study, we started with pure magnesium (Mg) powders and Zn sheets, and successfully fabricated Mg_xZn_y/Zn composites using accumulative roll bonding (ARB). The influence of varying ARB cycle numbers on their microstructures, performance in relation to mechanical parameters, corrosion resistance, and cytotoxicity was comprehensively studied. Following 15 ARB cycles, the composites demonstrated a refined Zn matrix phase with grains of 0.3 μm and uniformly distributed in situ nanoparticle reinforcements of Mg₂Zn₁₁ and MgZn₂. The composites after 15 ARB cycles exhibited an ultimate tensile strength of 560 MPa, yield strength of 540 MPa, and elongation of 12 %, significantly better than the mechanical properties of most Zn alloys reported to date. The significant improvement in the composites’ strength is primarily attributable to refinement of grain size and dispersion strengthening, both of which are facilitated by the in situ incorporation of nanoparticles. The corrosion rate reduced with more ARB cycles and after 15 ARB cycles the composites had an electrochemical corrosion rate of 150.2 μm/y and an immersion degradation rate of 50.6 μm/y. Further, an extract at 12.5 % concentration had a cell viability of 92.2 % toward MG-63 cells, indicating good biocompatibility.</div></div><div><h3>Statement of significance</h3><div>This work reports on Mg_xZn_y/Zn composites fabricated by accumulative roll bonding (ARB). The composite after 15 ARB cycles exhibited an ultimate tensile strength of 560 MPa, yield strength of 540 MPa, and elongation of 12 %, significantly higher than the mechanical properties of most Zn alloys published in the literature to date. The corrosion rate of the composites decreased with increasing number of ARB cycles and after 15 ARB cycles they showed an electrochemical corrosion rate of 150.2 μm/y and immersion degradation rate of 50.6 μm/y. Further, a 12.5 % concentration extract showed a cell viability of 92.2 % in relation to MG-63 cells, indicating good biocompatibility.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"194 ","pages":"Pages 514-529"},"PeriodicalIF":9.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143070151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Degeneration of the nucleus pulposus affects the internal volumetric strains and failure location of adjacent human metastatic vertebral bodies","authors":"Giulia Cavazzoni ,&nbsp;Margherita Pasini ,&nbsp;Christine L. Le Maitre ,&nbsp;Enrico Dall'Ara ,&nbsp;Marco Palanca","doi":"10.1016/j.actbio.2025.01.018","DOIUrl":"10.1016/j.actbio.2025.01.018","url":null,"abstract":"<div><div>Intervertebral disc (IVD) degeneration is suspected to affect the distribution of stress and strain near the vertebral endplates and in the underlying bone. This scenario is worsened by the presence of metastatic lesions on the vertebrae (primarily thoracic vertebrae (60–80 %)) which increase the risk of fracture. As such, this study aimed to evaluate the effect of IVD degeneration on the internal volumetric strains and failure modes of human metastatic vertebral bodies.</div><div>Five human thoracic spinal segments including one vertebra with lytic metastases and one radiologically healthy vertebra (control) were <em>in situ</em> tested in pure compression within a μCT scanner (isotropic voxel size = 39μm). Each specimen was tested in the elastic regime before and after inducing mock IVD degeneration (enzymatic degeneration with collagenase); and at failure after IVD degeneration. The volumetric strain field was measured using a global Digital Volume Correlation approach (BoneDVC).</div><div>After IVD degeneration, larger maximum (+187 %, <em>P</em> = 0.002, 95 % CI= [-4447, -1209]) and minimum (+174 %, <em>P</em> = 0.002, 95% CI= [1679, 4258]) principal strains were observed in both metastatic and control vertebrae, with peak differences in correspondence of the IVD anulus fibrosus. IVD degeneration caused a transversal fracture pattern in the vertebrae with failure location onset in the middle portion of the vertebral body and in the cortical shell.</div><div>In conclusion, IVD degeneration was found to be a key factor in determining the failure mode, suggesting the clinical relevance of including IVD level of degeneration to assess patients’ risk of spinal instability.</div></div><div><h3>Statement of significance</h3><div>Vertebrae can be affected by pathologies, like bone metastases, while intervertebral discs tend to degenerate during life. Generally, these structures and pathologies are studied separately. In this study, we explored the effects of artificial intervertebral disc degeneration on the mineralised tissues of the vertebrae with metastases. We observed that the induced intervertebral disc degeneration changes the mechanical behaviour of the vertebral trabecular bone. We believe that the findings of this study may influence the scientific community to develop new clinical tools for the prediction of the risk of fracture in vertebrae with spinal metastases, including the degeneration of the intervertebral discs as a parameter.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"194 ","pages":"Pages 258-269"},"PeriodicalIF":9.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142973622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Signs of in-vivo aging of zirconia from explanted dental implants with porous coating after several years in function","authors":"Ralf Kohal ,&nbsp;Thierry Douillard ,&nbsp;Clarisse Sanon ,&nbsp;Andraž Kocjan ,&nbsp;Jerome Chevalier","doi":"10.1016/j.actbio.2025.01.020","DOIUrl":"10.1016/j.actbio.2025.01.020","url":null,"abstract":"<div><div>The present study investigated the <em>in vivo</em> aging of yttria-stabilized zirconia (YSZ) oral implants (ZiUnite®) removed after 37 to 181 months. These implants featured a porous zirconia surface to enhance osseointegration. They were placed in prospective clinical investigations and had to be explanted due to peri‑implant bone breakdown. Since no single clinical/non-clinical parameter or combination of parameters were found to influence the bone loss, we have assessed the extent of the <em>in vivo</em> aging, known as low temperature degradation (LTD), on five explants as a possible critical influencing parameter. This research represents, to the best of our knowledge, the first report on low-temperature degradation-induced tetragonal-to-monoclinic (<em>t-</em>m) transformation in clinically applied YSZ oral implants after up to 15 years.</div><div>Using scanning electron microscopy (SEM) and focused ion beam (FIB)-SEM tomography, the analysis revealed significant surface <em>t-</em>m transformation, pronounced micro-cracking of the porous coating, and degradation. This extensive transformation and resultant volume expansion may have negatively impacted the bone-to-implant interface, contributing to clinical failure. Additionally, differently produced YSZ implants can exhibit varied behaviors, even with identical raw materials. The presented type of assessment of susceptibility to <em>in vivo</em> aging of oral implants could inspire the study protocol for other medical device systems.</div></div><div><h3>Statement of significance</h3><div>This study is the first to document substantial <em>t-</em>m transformation of clinically used YSZ implants after up to 15 years in the oral environment. Extensive <em>t-</em>m transformation in the porous coatings at body temperature occurred rapidly, leading to microcracking and potential loss of cohesion with the implant bulk. The porous, cracked zirconia coatings were linked to brittle fractures <em>in vivo</em> and it is hypothesized that these changes possibly contributed to bone loss, loss of osseointegration and subsequent implant failures. The findings of such transformation underscore the potential clinical risks of these zirconia coatings leading to the mentioned changes. The present assessment method could serve as a valuable protocol model for investigating the <em>in vivo</em> aging susceptibility of other medical devices.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"194 ","pages":"Pages 498-513"},"PeriodicalIF":9.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143017850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantifying structural changes in organised biomineralized surfaces using synchrotron Polarisation-Induced Contrast X-ray Fluorescence","authors":"Hui Lynn Ooi ,&nbsp;Alexander Morrell ,&nbsp;Aaron LeBlanc ,&nbsp;Slobodan Sirovica ,&nbsp;David Bartlett ,&nbsp;Owen Addison","doi":"10.1016/j.actbio.2025.01.042","DOIUrl":"10.1016/j.actbio.2025.01.042","url":null,"abstract":"<div><div>The quantitative characterization of the structure of biomineral surfaces is needed for guiding regenerative strategies. Current techniques are compromised by a requirement for extensive sample preparation, limited length-scales, or the inability to repeatedly measure the same surface over time and monitor structural changes. We aim to address these deficiencies by developing Calcium (Ca) K-edge Polarisation Induced Contrast X-ray Fluorescence (PIC-XRF) to quantify hydroxyapatite (HAp) crystallite structural arrangements in high and low textured surfaces. Minimally prepared human dental enamel was used as an exemplar to quantify initial surface structures, and the disruption caused by short dietary acid exposures. By measuring surfaces at different rotational angles relative to a polarised focused (2×2 µm) monochromatic X-ray source (at either 4049.2 and 4051.1 eV) it was possible to discriminate the principal and secondary orientations of surface crystallites, along with their texture. It was also possible to quantify the organisation of crystallites in both low (enamel cross-sections) and highly textured (facial enamel) surfaces including the identification of crystallites aligned perpendicular to the surface—a challenge for other synchrotron techniques. Surface modifications following short term acid erosion (affecting &lt;20 µm of the enamel surface depth) were detected as significant shifts in principal crystallite orientation (<em>p</em> &lt; 0.001) and as a marked reduction in surface texture (<em>p</em> &lt; 0.001). Findings suggest preferential dissolution of HAp based on crystallite angular orientation. We demonstrate that PIC-XRF is a powerful tool to quantify biomineral surfaces, with minimal sample preparation that enables monitoring of surface structural changes through repeated measurements.</div></div><div><h3>Statement of significance</h3><div>This study introduces Calcium (Ca) K-edge Polarisation Induced Contrast X-ray Fluorescence (PIC-XRF) as a method for quantifying the structure of biomineral surfaces, addressing limitations in existing techniques that require extensive sample preparation and cannot repeatedly measure the same surface. By using minimally prepared dental enamel, PIC-XRF successfully discriminated between principal and secondary orientations of hydroxyapatite crystallites, including end-on crystallites—a challenge for other synchrotron methods. Additionally, PIC-XRF detected significant structural changes due to short-term acid erosion. This technique's potential to repeatedly and non-invasively analyze biomineral surfaces offers new opportunities for understanding surface dynamics and guiding regenerative treatments.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"194 ","pages":"Pages 194-203"},"PeriodicalIF":9.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143049070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}