Acta Biomaterialia最新文献

{"title":"Mechanically compliant multifunctional bioadhesive hydrogel for rapid wound repair","authors":"Meng Wu,&nbsp;Yan Shi,&nbsp;Jinrui Li,&nbsp;Jiaxuan Zhao,&nbsp;Tingting Yang,&nbsp;Hu Hou,&nbsp;Ming Kong","doi":"10.1016/j.actbio.2026.08.027","DOIUrl":"10.1016/j.actbio.2026.08.027","url":null,"abstract":"<div><div>Bioadhesives in surgery are receiving increasing attention because of their ease of handling and desirable ability to promote wound closure; however, their mechanical mismatch with skin tissue and insufficient multifunctionality hinder clinical application. A mechanically compliant, multifunctional bioadhesive hydrogel (PATF) composed of polyacrylamide (PAM), alginate (Alg), tannic acid (TA), and ferric chloride (FeCl₃) has been developed for rapid wound repair. The covalently crosslinked PAM network provides structural integrity, while multiple noncovalent interactions (Alg/Fe³⁺ ionic bonds, hydrogen bonds, and TA/Fe³⁺ coordination) endows the hydrogel with skin-like modulus (∼25 kPa), improved toughness (328.9 kJ/m³), ultra-stretchability (∼2500% strain), and low hysteresis (&lt;21%). PATF hydrogel exhibits outstanding conformational adhesion with the skin surface, 5.25-fold stronger than that of commercial 3M Tegaderm, and can be readily detached on demand in the presence of FeCl₃ solution. Furthermore, multifunction involving antioxidant capacity, photothermal therapy–mediated antibacterial efficacy, comparable conductivity to native skin tissues, and superior hemostatic performance enables PATF hydrogel (with near-infrared irradiation) to suppress inflammation, promote collagen deposition, and enhance angiogenesis, collectively accelerating healing of infected full-thickness skin wounds within 7 days. These integrated mechanically and biologically compliant properties make PATF hydrogel a versatile candidate for fast, effective wound repair.</div></div><div><h3>Statement of Significance</h3><div>This study develops a rationally designed mechanically compliant multifunctional bioadhesive hydrogel (PATF) through a hybrid crosslinking network. The covalently crosslinked PAM network ensures structural integrity, while multiple non-covalent interactions endow the PATF hydrogel with skin-like modulus, improved toughness, ultra-stretchability, and low hysteresis. It exhibits outstanding conformational adhesion with skin surface, which is 5.25-fold stronger than that of 3M Tegaderm, and could be detached easily on demand. Its antioxidant capacity, PTT mediated antibacterial efficacy, comparable conductivity to native skin tissues, and superior hemostatic performance enable PATF hydrogel to suppress inflammation, promote collagen deposition, and enhance angiogenesis, collectively accelerate infected full-thickness skin wound healing within 7 days and hair follicle regeneration, making it a promising candidate for wound management</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"223 ","pages":"Pages 138-152"},"PeriodicalIF":10.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148765871","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":"Photosensitive ropivacaine- and chlorin e6-loaded hydrogel targeting the substance P-tachykinin receptor 1-toll-like receptor 7 axis enhances photodynamic and photothermal therapy against oral cancer","authors":"Yingbo Feng,&nbsp;Junbo Zhao,&nbsp;Mingming Zhang","doi":"10.1016/j.actbio.2026.09.003","DOIUrl":"10.1016/j.actbio.2026.09.003","url":null,"abstract":"<div><div>This study examines the important role of neuro-tumoral crosstalk in oral squamous cell carcinoma (OSCC) progression and therapy. We identified that dorsal root ganglia (DRG)-secreted substance P (SP) activates a pro-metastatic Tacr1-Tlr7 neuroinflammatory axis. To therapeutically disrupt this axis, a multifunctional photosensitive hydrogel patch (PDA/Rop-Ce6@DA-HA) was engineered. This patch co-delivers the local anesthetic ropivacaine (Rop) to block SP release from neurons and the photosensitizer chlorin e6 (Ce6) for combined photothermal (PTT) and photodynamic therapy (PDT). Under near-infrared irradiation, the patch enabled controlled drug release and synergistic PTT/PDT effects. In orthotopic and subcutaneous OSCC models, this combinatorial strategy markedly reduced SP levels, inhibited the Tacr1-Tlr7 axis and downstream PI3K/Akt signaling, increased tumor cell apoptosis, and produced stronger antitumor effects. The results support a biomaterial-based strategy that combines local neuromodulation with phototherapy for OSCC treatment.</div></div><div><h3>Statement of significance</h3><div>This study develops a photosensitive PDA/Rop-Ce6@DA-HA hydrogel patch that integrates photothermal therapy, photodynamic therapy, and local neural modulation for oral squamous cell carcinoma. By blocking DRG-derived substance P release and suppressing the SP-Tacr1-Tlr7 axis, the biomaterial targets neuro-tumoral crosstalk while enabling localized light-triggered tumor ablation. The work links biomaterial design with a defined neuroinflammatory mechanism and provides a combined strategy for improving oral cancer treatment.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"223 ","pages":"Pages 216-235"},"PeriodicalIF":10.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148889711","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":"Lauroylated peptide dendrimers with potent and broad-spectrum antimicrobial activity against multidrug-resistant bacteria","authors":"An Yan,&nbsp;Tianyu Zhang,&nbsp;Xingyu Wang,&nbsp;Sijing Wu,&nbsp;Ying Cai,&nbsp;Zhongxiang Wu,&nbsp;Liunan Wang,&nbsp;Ziyang Cui,&nbsp;Yiran Duan,&nbsp;Yajun Han,&nbsp;Guoliang Jiang,&nbsp;Zhiye Zhang","doi":"10.1016/j.actbio.2026.08.042","DOIUrl":"10.1016/j.actbio.2026.08.042","url":null,"abstract":"<div><div>Peptide dendrimers, characterized by their branched structure and densely arrayed surface amino acids or peptides, offer enhanced multivalency and unimolecular stability that collectively improve receptor engagement and bioactivity. Despite these advantages, broad application remains limited due to synthetic complexity, high production costs, and increased toxicity associated with larger dendrimer generations. To address these limitations, this study presents a streamlined design for peptide dendrimers featuring one or two branched heptapeptides tethered to a linear nonapeptide scaffold, with lauric acid introduced to the dendrimer core to drive self-assembly and enhance molecular stability. The resulting construct, designated Lau-IL-9-C2, demonstrated potent and broad-spectrum antibacterial activity against multidrug-resistant strains, alongside high biocompatibility in both <em>in vitro</em> and <em>in vivo</em> models. Mechanistic investigations revealed that Lau-IL-9-C2 exerted bactericidal effects through dual modes of action, not only disrupting bacterial membranes by targeting lipoteichoic acid (LTA), lipopolysaccharide (LPS), and phosphatidylglycerol but also inhibiting intracellular biological processes. Lau-IL-9-C2 also eradicated bacterial biofilms and persister cells and exhibited sustained efficacy without resistance development. In a murine wound infection model, Lau-IL-9-C2 achieved significant therapeutic outcomes, effectively clearing bacterial burden and accelerating wound healing. These findings support the rational design of structurally accessible peptide dendrimers as a promising platform for next-generation antimicrobial therapeutics.</div></div><div><h3>Statement of significance</h3><div>Peptide dendrimers with enhanced multivalency and unimolecular stability that collectively improve bioactivity. However, higher dendrimer generations substantially increase synthetic complexity and production costs. To address these limitations, we present a minimal yet functionally robust branching strategy to construct peptide dendrimers featuring with one or two branched heptapeptides tethered to a linear nonapeptide scaffold, with lauric acid introduced to the dendrimer core to drive self-assembly and enhance molecular stability. The lead peptide dendrimer Lau-IL-9-C2 was identified with potent and broad-spectrum antimicrobial activity against multidrug-resistant bacteria and high biocompatibility in both <em>in vitro</em> and <em>in vivo</em> systems. These findings advance understanding of peptide dendrimer structure-activity relationships and support the development of simplified dendrimer-based antibiotics for the treatment of multidrug-resistant bacterial infections.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"223 ","pages":"Pages 486-502"},"PeriodicalIF":10.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148802913","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":"Gradient in Motion: Mechanical Stimulation Of Cells Cultured on Melt Electrowritten Scaffolds","authors":"Piotr Stanisław Zieliński,&nbsp;Pavan Kumar Reddy Gudeti,&nbsp;Marcus Koch,&nbsp;Peter Olinga,&nbsp;Marleen Kamperman,&nbsp;Małgorzata Katarzyna Włodarczyk-Biegun","doi":"10.1016/j.actbio.2025.12.053","DOIUrl":"10.1016/j.actbio.2025.12.053","url":null,"abstract":"<div><div>Tissue engineering often relies on scaffolds to support cell growth and proliferation. To accurately mimic damaged tissues, complex, supportive structures are required. One promising approach is Melt Electrowriting (MEW), a high-precision 3D printing technique that enables the fabrication of intricate scaffolds with exceptional control over structure and mechanics. In this study, we designed and printed gradient scaffolds comprising three distinct zones—square, rhombus, and radial—seamlessly connected with unprecedented precision achieving relatively small pore sizes, relevant for cells bridging. Mechanical testing revealed that Young’s modulus of the gradient scaffold corresponds to the average modulus of the three individual zones. Under applied force. Human dermal fibroblasts cultured on the gradient scaffolds exhibited zone-specific alignment, influenced by both scaffold design and mechanical forces. Under dynamic stimulation (7% cyclic tensile strain for 10 days, following 14 days of initial static culture), cell alignment was preserved, whereas in continuous static culture, alignment was lost after 24 days. The unique deformation responses of each scaffold zone to tensile strain played a key role in directing cell organization. This study demonstrates that a single applied force on the MEW-fabricated, precisely designed and printed gradient scaffold in xy-plane can induce distinct, zone-specific cellular responses. This occurs because the scaffold’s region-dependent deformation modes generate localized mechanical cues, leading to varied cell behaviors across the zones. Our findings open new avenues for advanced tissue engineering applications, particularly interesting for musculoskeletal repair, where scaffold design and mechanical stimulation can be locally tailored to enhance tissue regeneration.</div></div><div><h3>Statement of Significance</h3><div>This study introduces a gradient scaffold fabricated using Melt Electrowriting (MEW), a precise 3D printing method. The scaffold features three smoothly connected zones (square, rhombus, and radial) with distinct structures and mechanical properties. For the first time, we show how these gradient scaffolds guide human cell alignment and response under mechanical strain, mimicking how tissues behave in the body. We show that under a single applied load, different mechanical cues emerge for each zone, guiding localized cell behaviour. Importantly, only when dynamic mechanical forces were applied, cells maintained alignment, highlighting the importance of mechanical stimulation in tissue design. These findings have broad implications for improving scaffold design in tissue regeneration, particularly in load-bearing tissues like muscle or enthesis.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"224 ","pages":"Pages 272-284"},"PeriodicalIF":10.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145896322","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":"Engineering bioinspired, high-density collagen microgels with tunable intrafibrillar mineralization for accelerated osteogenesis in vitro and bone regeneration in vivo","authors":"Sofia M. Vignolo,&nbsp;Daniela M. Roth,&nbsp;May A.A. Fraga,&nbsp;Lillian Wu,&nbsp;Jameson A. Cosgrove,&nbsp;Avathamsa Athirasala,&nbsp;Angela S.P. Lin,&nbsp;Robert E. Guldberg,&nbsp;Luiz E. Bertassoni","doi":"10.1016/j.actbio.2026.02.003","DOIUrl":"10.1016/j.actbio.2026.02.003","url":null,"abstract":"<div><div>The development of biomaterials that mimic native bone remains a major challenge in regenerative medicine. Here, we present a bioinspired platform using high-density collagen hydrogels with tunable mineral content. These engineered microenvironments promote rapid osteogenesis <em>in vitro</em> without osteogenic supplements and accelerate bone regeneration <em>in vivo</em> in critical-sized defects. By modulating mineralization, we demonstrate that early mechanosensitive signaling in human mesenchymal stem cells is linked to matrix stiffness and biochemical composition. Within two hours, focal adhesion formation decreased with increasing mineral content, and fully mineralized scaffolds significantly increased nuclear YAP1 localization. By 24 h, RUNX2 expression was markedly increased in fully mineralized scaffolds, with 40.7 ± 3.9% RUNX2⁺ nuclei (<em>p</em> &lt; 0.0001), and this trend persisted at the gene expression level at 3 days. In a rat calvarial defect model, fully mineralized microgels significantly increased bone volume in males at 12 weeks (18.99 ± 2.66 mm³) compared to empty defects (11.60 ± 2.12 mm³, <em>p</em> = 0.0242), whereas females showed no added benefit of full mineralization. Two-way ANOVA confirmed significant effects of sex (<em>p</em> = 0.0006), treatment (<em>p</em> &lt; 0.0001), and their interaction (<em>p</em> = 0.0158). Histological analyses confirmed osteoinductive behavior across all microgel groups and highlighted reduced scaffold degradation and limited cellular infiltration in mineralized conditions. Together, these results demonstrate that tunable intrafibrillar mineralization modulates early stem cell mechanosensing and osteogenic priming <em>in vitro</em> and drives sex-dependent regenerative outcomes <em>in vivo</em>, emphasizing the need to balance scaffold mechanics and degradation to suit the biological context and improve clinical outcomes.</div></div><div><h3>Statement of significance</h3><div>This study introduces a strategy to fine-tune the properties of implantable materials for bone repair using microscale scaffolds with controlled mineral content. By adjusting composition at the nanoscale, our work identifies how early cellular responses can be directed to influence long-term healing. Importantly, the findings reveal that regenerative outcomes vary by sex, emphasizing the need to consider biological differences in biomaterial design. This work offers new insight into how tailored physical environments can guide tissue repair and highlights the potential for precision approaches in bone graft development.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"224 ","pages":"Pages 72-86"},"PeriodicalIF":10.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146133715","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":"Surface-engineered WE43 magnesium implants promote bone repair and reshape the peri-implant immune microenvironment","authors":"Christian H. Bucher,&nbsp;Heilwig Fischer,&nbsp;Agnes Ellinghaus,&nbsp;Oskar Schmidt-Bleek,&nbsp;Denise Jahn,&nbsp;Ana Prates Soares,&nbsp;Serafeim Tsitsilonis,&nbsp;Georg N. Duda,&nbsp;Max Heiland,&nbsp;Katharina Schmidt-Bleek,&nbsp;Carsten Rendenbach","doi":"10.1016/j.actbio.2026.09.023","DOIUrl":"10.1016/j.actbio.2026.09.023","url":null,"abstract":"<div><div>Although the early inflammatory response to biomaterial implantation has been investigated, less is known about how degradation products shape the immune environment during later stages of regeneration. To address this, we analyzed immune responses to WE43 magnesium alloy implants (Mg-Y-Nd-Zr alloy) with distinct surface states: uncoated WE43 and WE43 implants surface-modified by plasma electrolytic oxidation (PEO) using a phosphate electrolyte. These implants were evaluated in a mouse osteotomy model during bone formation, when degradation-related effects on the peri-implant immune environment become increasingly relevant. Ex vivo immunogenicity tests showed that both implants induced moderate levels of TNFα and IL-8 responses, indicating immunological inertness. In vivo bone formation, implant degradation, and immune cell composition were assessed. Micro-CT analysis revealed enhanced bone regeneration in the WE43 PEO group, indicated by higher bone-to-callus ratio and trabecular bone thickness, and reduced cortical bone lysis. Implant density mapping demonstrated a slower, more homogeneous degradation pattern for PEO-modified implants. Flow cytometry analysis revealed an increased leukocyte accumulation and higher proportion of pro-inflammatory M1 macrophages surrounding WE43 implants, whereas WE43 PEO implants were associated with more balanced macrophage, dendritic, and natural killer cell profile. Spatial histological analyses corroborated these findings, showing closer proximity between macrophages and osteoblasts to PEO-modified implants. By integrating degradation mapping with spatial immune and histological analyses, this study identifies distinct peri-implant immune signatures associated with PEO-modulated magnesium degradation during bone regeneration. In conclusion, PEO is associated with a less pro-inflammatory peri-implant immune profile at day 28, and improved bone healing parameters.</div></div><div><h3>Statement of significance</h3><div>Biodegradable magnesium implants can support bone repair, but how their surface treatments shape the local immune response is still unclear. This study compares unmodified WE43 magnesium implants with plasma electrolytic oxidation (PEO)–modified WE43 implants in a mouse osteotomy model. By combining micro-CT bone analysis, spatial mapping of implant degradation, flow cytometry–based immune profiling, and histology, we link distinct degradation patterns to specific peri-implant immune signatures. PEO-modified implants degraded more slowly and uniformly, reduced cortical bone lysis, and improved bone regeneration. They were associated with a more balanced profile of macrophages, dendritic cells, and natural killer cells, whereas unmodified implants showed increased leukocyte counts and pro-inflammatory M1 macrophages. These findings inform the design of immunomodulatory, degradable implants to improve bone healing.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"224 ","pages":"Pages 54-71"},"PeriodicalIF":10.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148978980","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":"Special issue: Biodegradable biomaterials for bone, joint, and soft tissue regeneration in orthopedics","authors":"Sunil Kumar Boda,&nbsp;Vera Hintze,&nbsp;Michael Gelinsky,&nbsp;Greeshma Thrivikraman","doi":"10.1016/j.actbio.2026.09.048","DOIUrl":"10.1016/j.actbio.2026.09.048","url":null,"abstract":"","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"224 ","pages":"Pages 1-3"},"PeriodicalIF":10.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149083138","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":"Ultrafast water-responsive shape-adaptive magnesium-loaded silk fibroin-based scaffold modulates macrophage glycolytic reprogramming for endogenous cartilage regeneration","authors":"Zhinan Mao,&nbsp;Xuewei Bi,&nbsp;Yu Qin,&nbsp;Ming Li,&nbsp;Mili Tilieke,&nbsp;Ke Ma,&nbsp;Lei Chen,&nbsp;Rui Zheng,&nbsp;Yongsheng Jie,&nbsp;Jinzhu Jing,&nbsp;Yongcan Huang,&nbsp;Juan Guan,&nbsp;Robert O. Ritchie,&nbsp;Xiong Shu,&nbsp;Ling Qin,&nbsp;Yufeng Zheng","doi":"10.1016/j.actbio.2026.07.062","DOIUrl":"10.1016/j.actbio.2026.07.062","url":null,"abstract":"<div><div>Shape-adaptive scaffolds have shown promise in regenerating critical-sized irregular articular cartilage defects. However, limitations on the speed and degree of adaptation, mechanical robustness, host integration, and targeted biological functionality have greatly restricted their clinical application. In this study, an ultrafast (0.29 s) water-responsive shape-adaptive Mg-containing silk fibroin-gelatin methacryloyl scaffold was fabricated using a simple photo-crosslinking combined with water vapor annealing. We demonstrated that the reversible weak hydrogen bonding interactions between water molecules and silk fibroin (SF) chains enabled the compressed scaffold to rapidly regain its original shape upon bodily fluid exposure, adapting to the cartilage defect geometry while establishing seamless integration with host tissues. During the early inflammation phase, the controllable and on-demand release of Mg²⁺ could promote M2-like macrophage polarization, which is associated with PI3K/AKT/mTOR activation and glycolytic remodeling; thereby remodeling a favorable immune microenvironment that enhanced the chondrogenic differentiation of endogenous bone marrow stem cells (BMSCs). <em>In vivo</em> rabbit critical-size osteochondral defect models confirmed that this scaffold facilitated robust hyaline cartilage formation enriched in chondrocytes and type II collagen with seamless marginal integration at 12 weeks post-implantation. Collectively, this ultrafast shape-adaptive silk scaffold represents a cell-free therapeutic platform for irregular full-thickness cartilage defects.</div></div><div><h3>Statement of significance</h3><div>This study presents an ultrafast water-responsive (0.29 s) shape-adaptive Mg-containing silk fibroin-based scaffold to facilitate cartilage regeneration. The water vapor annealing treatment provides gentle and uniform stimulation, enabling the quasi-linear and controllable regulation of the performance of silk fibroin (SF) porous scaffolds. The compressed scaffold can rapidly adapt to irregular geometry. The controllable and on-demand release of Mg²⁺ create a favorable immune microenvironment for enhancing in-situ cartilage regeneration, and transcriptomic anlysis revealed the key immunomodulatory mechanisms. These findings provide a promising strategy for treating critical-size irregular cartilage defects.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"222 ","pages":"Pages 289-309"},"PeriodicalIF":10.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148650018","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":"Zwitterionic tissue expanders reduce infection and fibrosis for enhanced biocompatibility","authors":"Stephanie L. Fung,&nbsp;Matthew R. Aronson,&nbsp;William R. Katowitz,&nbsp;James A. Katowitz,&nbsp;Riccardo Gottardi","doi":"10.1016/j.actbio.2026.07.039","DOIUrl":"10.1016/j.actbio.2026.07.039","url":null,"abstract":"<div><div>Current osmotic tissue expanders suffer from protein adsorption, bacterial colonization, and excessive fibrotic encapsulation that compromise device performance. In this study, we synthesized zwitterionic hydrogels using methyl methacrylate, n-vinyl pyrrolidone, and varying percentages (5–50%) of [2-(Methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA) to simultaneously enhance swelling capacity while reducing biological fouling. <em>In vitro</em> characterization demonstrated that SBMA incorporation significantly increased swelling potential while maintaining the mechanical integrity required for effective tissue expansion. Zwitterionic hydrogels exhibited superior resistance to lysozyme, fibrinogen, and bovine serum albumin (BSA) adsorption compared to ionized controls. Bacterial attachment studies revealed reduced <em>Staphylococcus aureus</em> attachment on zwitterionic surfaces, particularly in lysozyme-containing environments that mimic physiological conditions. Subcutaneous implantation in Sprague Dawley rats for 14 days showed that hydrogels with 5–30% SBMA formed significantly thinner fibrous capsules compared to ionized controls, with the 30% SBMA formulation producing the most uniform and loose capsular matrix. These results demonstrate that zwitterionic hydrogels represent a significant advancement in osmotic tissue expansion technology, addressing key limitations of current devices through bulk incorporation of zwitterionic monomers, potentially improving clinical outcomes and reducing the need for revision surgeries.</div></div><div><h3>Statement of significance</h3><div>Tissue expanders are medical devices used to stretch skin and soft tissues for reconstructive surgery, but current osmotic expanders fail due to protein buildup, bacterial infections, and excessive scar tissue formation. We developed new hydrogel materials incorporating zwitterionic compounds, <em>i.e.</em>, molecules with balanced positive and negative charges, that resist biological fouling while maintaining effective tissue expansion properties. Our zwitterionic hydrogels demonstrated superior resistance to protein adsorption and bacterial attachment compared to conventional materials. Most importantly, when implanted in rats, these hydrogels formed significantly thinner, less dense scar tissue capsules, particularly the 30% zwitterionic formulation. This breakthrough addresses major clinical limitations of current tissue expanders and could reduce surgical complications and the need for revision procedures, ultimately improving patient outcomes in reconstructive surgery.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"222 ","pages":"Pages 173-184"},"PeriodicalIF":10.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148586193","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":"Artificial photosynthetic H₂/O₂-producing nanosheets promote diabetic chronic wound healing through antibacterial and anti-apoptotic pathways","authors":"Zhongqiang Zhu,&nbsp;Ling Jiang,&nbsp;Jing Cheng,&nbsp;Yuyue Zhang,&nbsp;Haiyan Wang,&nbsp;Meng Qin,&nbsp;Xiaoming Huang,&nbsp;Xingyu Chen,&nbsp;Jianshu Li","doi":"10.1016/j.actbio.2026.08.014","DOIUrl":"10.1016/j.actbio.2026.08.014","url":null,"abstract":"<div><div>Diabetic chronic wounds represent a significant clinical challenge, characterized by bacterial biofilms, impaired vascularization, and persistent oxidative stress. While photothermal therapy (PTT) has emerged as a potential antibacterial approach, its efficacy is often constrained by limited photothermal conversion efficiency and unintended aggravation of oxidative stress. Drawing inspiration from the coordinated energy conversion and photoprotective mechanisms of natural photosynthesis, we developed a biomimetic two-dimensional H₂/O₂-producing photothermal (2D-HPT) nanosheets. This nanosheets integrate liquid-phase exfoliated CaSi₂ nanosheets functionalized with palladium nanoparticles and polyvinylpyrrolidone to execute an artificial photosynthetic cycle. Under near-infrared (NIR) light irradiation, the nanosheets exhibit an enhanced photothermal effect and hydrolytic H₂ generation, thereby achieving efficient biofilm disruption. Crucially, the continuous release of H₂ and in situ catalytic production of O₂ not only mimic natural photosynthetic outputs but also programmatically activate a cell-protective mechanism. This process, analogous to non-photochemical quenching in plants, results in scavenging of reactive oxygen species (ROS), stabilization of mitochondrial membrane potential, and suppression of apoptosis. These coordinated actions significantly downregulate pro-inflammatory cytokines (IL-6/TNF-α) and promote VEGF/CD31-mediated angiogenesis, collectively accelerating the healing of infected diabetic wounds. Our work thus provides an effective strategy for chronic wound repair.</div></div><div><h3>Statement of significance</h3><div>This study presents a biomimetic strategy for treating diabetic chronic wounds, which are clinically challenging due to bacterial biofilms and persistent oxidative stress. Inspired by natural photosynthesis, the designed two-dimensional H₂/O₂-producing photothermal nanosystem not only disrupts biofilms via enhanced photothermal effects and hydrolytic H₂ generation under NIR irradiation, but also continuously releases H₂ and catalytically produces O₂ to activate a cell-protective mechanism. This coordinated action alleviates oxidative stress, reduces inflammation, and promotes VEGF/CD31-mediated angiogenesis, collectively accelerating wound healing. The work offers an effective innovative therapeutic approach for chronic wound management.</div></div>","PeriodicalId":237,"journal":{"name":"Acta Biomaterialia","volume":"222 ","pages":"Pages 553-571"},"PeriodicalIF":10.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148698681","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}