Decellularized extracellular matrices (dECMs) are promising biomaterials for generating tissue-specific in vitro models due to their organotypic extracellular matrix (ECM) protein profiles compared to natural and synthetic alternatives. However, most dECM-based hydrogels rely on collagen fibrillogenesis, resulting in limited mechanical tuneability and cell instructivity. Here, we developed LungMA, a photocrosslinkable, methacrylated lung dECM hydrogel engineered for precise stiffness modulation and tissue-specific lung cancer modelling. The decellularization process removed >99 % of native DNA, ensuring minimal cellular remnants while preserving key ECM components including laminin-332, collagen VI, and heparan sulfate proteoglycan 2 (HSPG2). Methacrylation and photoinitiation enabled formation of stable LungMA hydrogels with tunable stiffnesses ranging from 1 kPa (healthy lung) to 4 kPa (fibrotic lung). Using A549 non-small-cell lung cancer (NSCLC) cells, we demonstrated that matrix composition and stiffness influenced cell morphology, proliferation, and drug response. Soft LungMA (1 kPa) promoted motile, sheet-like cellular organization, whereas stiff LungMA (>4 kPa) induced compact spheroids associated with chemoresistance. Increasing matrix stiffness resulted in an increase in doxorubicin IC50 from 0.40 μM (soft LungMA) to 1.23 μM (stiff LungMA), and cisplatin IC50 from 0.03 μM to 8.34 μM, reflecting clinical observations where fibrosis correlates with poor prognosis. In contrast, gelatin methacryloyl (GelMA) and basement membrane extract (BME)-based hydrogels failed to induce these stiffness-dependent effects during cisplatin treatment underscoring the instructive role of lung-specific ECM components and matrix stiffness on chemotherapeutic outcomes. LungMA provides a physiologically relevant, mechanically tunable, lung-specific platform that replicates in vivo-like cancer phenotypes and drug responses. This work supports the application of LungMA for oncology research, disease modelling, and high-throughput drug screening as a clinically relevant, non-animal alternative for lung cancer studies.

Matrix biology has traditionally focused on proteins, glycosaminoglycans, and polysaccharides as the main structural and functional elements of the extracellular matrix (ECM). Each of these components is fundamentally associated with the surrounding aqueous environment. However, water is not just a passive solvent—its organization and interactions with macromolecules influence tissue biomechanics, biochemical signaling, and cell behavior. Understanding the role of water is crucial for elucidating how tissues grow, adapt, repair, and regenerate. Water is the most abundant molecule in biological tissues and plays a key role in shaping the architecture and function of the ECM. Processes such as osmosis across the cell membrane and water imbibition in both intracellular and extracellular colloids (e.g., proteins, carbohydrates, etc.) are fundamental to ECM function. These processes affect its viscoelastic and poroelastic properties and, consequently, its ability to support various cellular processes. This article explores the dynamic effects of water imbibition on the ECM, highlighting implications for tissue mechanics, cell behavior, and potential clinical applications. By investigating these dynamics, we aim to deepen our understanding of physiological and pathological processes involving the ECM, thereby advancing the field of matrix biology. Using modern experimental techniques and targeted research questions, we can uncover water’s active roles in tissue homeostasis, remodeling, mechanotransduction, and disease.

The development and characterisation of decellularised tissues have become a focus in biomaterial sciences and tissue engineering. In the extracellular matrix (ECM) of tissues, water acts as a structural and biochemical mediator, maintaining hydration, enabling molecular transport, contributing to the regulation of mechanical properties, and facilitating biochemical reactions. However, the dynamics and behaviour of water inside hydrogel biomaterials are scarcely discussed, likely due to the limited availability of observation methods and models. In this study, differential scanning calorimetry (DSC) was applied to study the status of water in photocurable decellularised extracellular matrix (dECMMA) hydrogels; furthermore, 1H NMR time-domain nuclear magnetic resonance (TD-NMR) was combined with Solomon-Bloembergen-Morgan theory to determine the effective rotational correlation time of water in dECMMA. Additionally, the dynamics of bound water and bound-water fraction were calculated via an established two-site exchange model. The main finding is that the cartilage dECMMA showed a fast bound water tumbling rate. In contrast, lung dECMMA showed a high bound-water fraction compared with other dECMMA and gelatin methacrylate (GelMA) hydrogels. This work demonstrates how the convergence of DSC, NMR and theoretical modelling allows for the study of water status in hydrogels at the molecular level.

In the context of implanted medical devices, biofilm formation transforms otherwise inert biomaterials into persistent sources of infection that are highly resistant to antimicrobial therapy and immune clearance. This persistent problem demands a critical re-examination of how biofilms are conceptualized, studied, and modeled. Using tissue-mimicking gelatin methacryloyl hydrogels, we show that Staphylococcus aureus spatiotemporal biofilm dynamics are strongly regulated by matrix mechanics and nutrient availability. Nutrient-rich conditions promote hyperproliferative, eDNA-rich microcolonies that actively degrade polymer networks, whereas serum-supplemented conditions produce compact aggregates enriched with vesicle-like structures and serum-derived matrix components. Notably, 3D confinement revealed a previously unrecognized ‘budding’ dispersal mechanism unique to embedded biofilms. Integrating 3D-printed polycaprolactone implants shows that while implant surfaces promote bacterial adhesion, the surrounding microenvironment exerts primary regulatory control. Longitudinal tracking over 3 weeks recapitulates key biofilm hallmarks and challenges surface-centric paradigms of implant infections, providing a framework for dissecting infection mechanisms and guiding therapeutic strategies.

This study proposes a perforated, soft millirobot with dual functions: in situ mechanostimulation to enhance cell functionality and local cell delivery. Following protein modification and silica coating, the soft millirobots exhibit excellent biocompatibility, promoting cell adhesion and tissue ingrowth within their perforated architectures under both in vitro and in vivo conditions. They can apply in situ mechanostimulation to various cellular morphologies, including two-dimensional (2D) cell sheets, 3D cell-laden hydrogels, and ex vivo tissue models. The mechanical stimulation improves the functionality of muscle cells by enhancing cellular orientation, myotube contraction, and myocyte differentiation. In parallel, we develop an integrated robotic platform combining magnetic actuation with ultrasound imaging. It demonstrates the proof of principle that delivers 2D cell-sheet and 3D cell-laden biohybrid millirobots to narrow regions in an ex vivo pig liver model. This work expands the potential applications of soft millirobots in mechanobiology studies and future cell-based therapies.

To enhance the clinical use of scaffold-guided breast reconstruction (SGBR), the porcine model provides a reliable means of assessing scaffold biocompatibility and tissue regeneration. Understanding the immunological processes triggered by the implantation of medical-grade polycaprolactone (mPCL) scaffolds is essential for elucidating the underlying biology and optimizing the regenerative potential of tissue engineering and regenerative medicine (TE&RM) technologies. This observational work aims to characterize these in vivo processes through systematic, comprehensive immunohistochemical (IHC) analysis based on two preclinical large-animal studies. Key emphasis is placed on evaluating the interplay between immune cell-mediated foreign body response (FBR) and the cellular mechanisms required for successful soft-tissue regeneration, remodelling, and scaffold degradation. Findings indicate that the porcine model provides valuable insights into extracellular matrix (ECM) formation, the interactions between immune cells and the implant surface, and their spatial distribution within the scaffold’s porous architecture. This study further reflects the complexity and spectrum of macrophage phenotypes present 12 months after implantation, exhibiting distinct spatial distributions relative to the scaffold surface, consistent with their established roles in inflammation, tissue regeneration, and remodelling. It also emphasizes the importance of both cellular components and ECM deposition that coexists and may interact to create a distinct microenvironment that varies with local scaffold topography, resulting in location-dependent differences in cellular composition and ECM characteristics relevant to tissue reorganization and homeostasis. Furthermore, this research suggests that extensive neoangiogenesis and vascular remodelling throughout the scaffold architecture are essential for maintaining tissue viability and promoting autologous fat tissue regeneration within the scaffold’s large, fully interconnected pores. These factors are critical for understanding in vivo tissue regeneration following mPCL scaffold implantation and for advancing the translation of SGBR into clinical practice.

Osteosarcoma remains a lethal paediatric malignancy when it metastasises to lung, yet therapeutic progress has stalled for decades, in part because preclinical models poorly capture patient specific tumor microenvironments. Here, patient- derived osteosarcoma (PDOS) cells are assembled into uniform, matrix-free organoids and then embedded into photocrosslinkable extracellular matrices with independently tuneable stiffness and composition: collagen-rich gelatin methacryloyl (GelMA) or basement membrane protein-enriched lung decellularized extracellular matrix (dECM) methacryloyl (LungMA), each tuneable to soft (approximately 1 kPa) or stiff (approximately 4 kPa) conditions. Embedding converts otherwise compact organoids into invasive, expanding structures and increases resistance to doxorubicin relative to both 2D cultures and matrix-free organoids. Matrix identity influenced early invasion kinetics and treatment response, with LungMA promoting more aggressive invasion shortly after embedding and greater chemoresistance than GelMA, particularly under stiffer conditions. Image-based segmentation of core and invasive compartments revealed a critical divergence between metabolic viability readouts and functional invasion inhibition under chemotherapy, exposing limitations of conventional screening endpoints. These findings establish stiffness-controlled, tissue-derived extracellular matrix (ECM) organoid systems as a tuneable platform to interrogate microenvironment-driven osteosarcoma aggressiveness and to advance patient-specific assessment of therapeutic vulnerability in metastatic niche-like contexts.

This study investigates the effects of hydration, temperature, and γ-irradiation on the structural, thermal, and mechanical properties of Lactoprene® 7415, a linear block copolymer consisting of 74% lactide, 15% trimethylene carbonate, 11% ε-caprolactone repeating units, and 40 wt% β-TCP/Lactoprene® 7415 composite. Techniques including static and dynamic mechanical testing or differential scanning calorimetry have evidenced structural changes resulting from irradiation- or water-induced crystallinity, crosslinking, chain scission or plasticization. Notably, hydration and physiological temperatures reduced the mechanical properties but conferred hyperelastic characteristics to the polymeric and composite samples. γ-irradiation was detrimental for the mechanical properties, except for those of the pure polymer in dry conditions. Our results evidence a complex interplay between the polymer, particles, temperature, hydration and water. Such observations could have implications in future designs and investigations of composite materials for scaffold-guided bone regeneration (SGBR), such as sterilization processes or minimally invasive surgery.

Melt electrowriting (MEW) features a raised nozzle positioned several millimeters above the collector, enabling high-contrast videography of the molten polymer jet. Despite this exceptional visual access, routine process monitoring based on computer vision (CV) remains challenging due to the lack of user-friendly and interoperable software. Here, open-source CV software was developed for processing backlit jet images and analyzing various aspects of the MEW jet, including jet angle, lag, length, diameter, area and volume. The software extracts values frame-by-frame either post-process or in real-time, enabling quantitative temporal characterisation of the MEW jet. By enabling flexible specification of measurement locations for each metric, it becomes possible to tailor metric extraction to a wide range of applications and studies. Since MEW is a multiparametric technology, this study demonstrates that performing essential measurements contributes to identifying the optimal conditions for stable processing. Jet dynamics associated with fiber pulsing, a significant processing defect, were identified and visualised in detail by transitioning between stable and unstable processing regimes. Finally, real-time measurements were utilised to implement closed-loop process control and demonstrate the software’s adaptability to other printer systems. Available to users via GitHub, the open-source software provides advanced quantitative jet analysis to the broader MEW research community.

Treatment of critical-size bone defects has been enhanced by advancements in scaffold-guided bone regeneration (SGBR), for which the usage of osteogenic bone graft material is crucial. To optimize the extraction of bone graft, the aspirator + reaming-aspiration (ARA) concept has recently been evaluated in a preclinical in-vivo study as an alternative intramedullary harvesting strategy to the well-known Reamer-Irrigator-Aspirator 2 system (RIA 2 system). As part of the in-vivo study, bone graft obtained from sheep was applied together with a 3D-printed bioresorbable scaffold construct in an ectopic rat model. Fluorochrome labelling with calcein green (day 8), alizarin complexone (day 22) and xylenol orange (day 36) was performed at different timepoints post-surgically. After 8 weeks, probes from five experimental groups were explanted resulting in a total of 58 resin probes for further analysis. Fluorescence of 198 samples was assessed semi-quantitatively through applying a three-stage evaluation scale (“none”, “minimal”, “intense”) by two assessors (LPW and ACB) independently. No fluorescence was defined as the absence fluorescent clusters over the entire sample section after manual screening at 20× magnification. Minimal fluorescence was defined as the presence of a maximum of three fluorescent clusters at independent image sections at 20× magnification. Intense fluorescence was defined as a minimum of three fluorescent clusters at independent image sections at 20× magnification. Preliminary descriptive statistical results are shown in Figure 1. All group 1 “Sc-samples” and 58% of group 3 “ScA samples” show no fluorescence. Minimal fluorescence was observed for 5% of group 2 “ScRIA2 samples”, 32% of group 3 “ScA samples”, 14% of group 4 “ScRa samples” samples, and 41% of group 5 “ScARA samples”. Intense fluorescence was observed for 95% of group 2 “ScRIA2 samples” samples, 10% of group 3 “ScA samples”, 86% of group 4 “ScRA samples” and 53% of group 5 “ScARA samples”. In conclusion, our preliminary data indicate comparable active bone regeneration and bone formation of bone graft material harvested with the new ARA concept compared to the RIA 2 system. In a next step, quantification of the fluorescent sample surface will be performed. Furthermore, advanced statistical analysis and putting the results in relation with histological and immunohistochemical analysis of paraffin samples are required. For any figures or tables, please contact the authors directly.

Extracellular matrices (ECMs) are foundational to all biological systems and naturally evolved as an intersection between living systems and active materials. Despite extensive study, research on ECMs often overlooks their structural material complexity and systemic roles. This Perspective argues for a holistic examination of ECMs from a materials science viewpoint, emphasizing their highly variable compositions, multiscale organizations, dynamic changes of mechanical properties, and fluid interactions. By transcending taxonomic and environmental boundaries, we aim to reveal underlying principles governing architectures, functions and adaptations of ECMs, with a focus on animal, plant and biofilm ECMs. Highlighting the role of water in ECM composition and function, and road-mapping the technical challenges in characterizing these complex materials, we propose an interdisciplinary framework to advance our understanding and application of ECMs across multiple scientific fields. Key focus areas include specimen preparation, multiscale analysis, and multimethod approaches. The optimization of specimen preparation first enables us meeting both biological and experimental conditions. The use of techniques that bridge the multiscale nature of ECMs is next, followed by integration of multiple techniques that are both position- and time-resolved, including structural and spectroscopic imaging. Such a coordinated approach promises not only to enrich our knowledge of biological systems but also to encourage the development of innovative bioinspired materials, with transformative implications across environmental science, health, and biotechnology.

Victoria Camilieri-Asch and colleagues introduce cartilage biology in chondrichthyans, the clade of fishes that includes sharks and rays.

Bone defects caused by trauma, cancer, or infection, are problematic for surgeons and patients alike. Critical-sized bone defects will not heal over one's lifetime without (surgical) intervention. Current treatment options have significant limitations and a strong demand for clinically translatable alternatives, such as scaffold-guided bone regeneration (SGBR). Our interdisciplinary team has studied SGBR for critical-sized bone defects over the last two decades in pre-clinical trials and demonstrated successful bone regeneration in a well-characterised and validated sheep segmental defect model. These findings were recently translated into a clinical setting, and we could provide bespoke SGBR solutions for selected patients in Australia and Germany who experienced critical-sized bone defects of 10 to 34 cm. Over the years, the scaffold design process has continuously improved, but a low-cost and efficient software tool that designs these scaffolds ‘on-the-fly’ according to the surgeon's needs while readily being 3D printable remains the main challenge. A semi-automatic patient-specific SGBR design workflow (Figure 1) was developed and implemented within Rhinoceros 3D and Grasshopper (R&G) software (Robert McNeel & Associates, USA). A dedicated in-house developed plugin enabled the export of 3D print-ready models. The workflow could be quickly adapted to different bone defect scenarios via a modular setup and produced scaffold designs based on an array of pore architectures, including the Voronoi tessellation that mimics natural trabecular bone. Lastly, it allowed the surgeon to verify the designs by overlaying them on medical images of the defect. The tool was validated by applying it to four clinical case studies: a complex multi-fragmentary femoral defect (Figure 2), a bilateral femoral defect, a segmental humerus defect, and a large volume craniomaxillofacial defect. All scaffolds were designed within 90 min, and the output models were free from surface mesh errors that inhibit accurate 3D printing. The designs showed an excellent, patient-specific fit when examined both digitally and physically using 3D-printed prototypes. Our workflow successfully designs patient-specific scaffolds with real-time responsiveness. It is currently being developed into a standalone software that allows surgeons to easily and quickly provide SGBR scaffold design solutions, with minimal user interaction using a simplified interface.

Osteosarcoma (OS), the most common malignant bone cancer in children and adolescents, has a five-year survival rate of 60% for primary cases and only 20% for metastatic cases. Despite decades of research, treatment options remain largely unchanged. Personalised models, such as patient-derived organoids (PDOs), promise to advance drug discovery to develop as end-goal patient-specific treatment concepts. Still, current approaches lack key extracellular matrix (ECM) components essential to mimic the tumour microenvironment more closely. This study aims to develop a bone-specific, photocrosslinkable ECM-based in vitro platform to enhance current capabilities in drug screening in OS. Porcine bones were demineralised with EDTA, and decellularisation methods were compared using sodium lauryl ether sulfate (SLES), Triton-X-100, their combination, and sodium chloride-induced osmotic shock. DNA quantification and haematoxylin and eosin staining confirmed successful decellularisation, with SLES and osmotic shock showing the highest efficiency, while osmotic shock demonstrated the best cytocompatibility. Glycosaminoglycan quantification and proteomics analysis demonstrated preserved ECM components, resembling some of the features of native tissue. The ECM was solubilised and functionalised with methacryloyl groups to create photocrosslinkable hydrogels with tuneable mechanical properties. Human osteoblasts (hOBs) encapsulated in dECM-MA hydrogels with Young's 5, 10, and 20 kPa moduli showed over 90% viability over an eight-week culture period. At 10 kPa, differentiation markers such as alkaline phosphatase (ALP) were elevated compared to the GelMA control. Morphologically, hOBs in dECM-MA displayed larger, more spread cells with extended lamellipodia. Future work will incorporate OS-PDOs into the dECM-MA platform to model OS and evaluate drug responses. Ultimately, this bone-specific ECM model has the potential to advance personalized medicine by facilitating the functional characterization of osteosarcoma (OS) and the screening of patient-specific therapies.

Hydrogels are frequently used in regenerative medicine due to their hydrated, tissue-compatible nature, and tuneable mechanics. While many strategies enable bulk mechanical modulation, little attention is given to tuning surface tribology, and its impact on cellular behavior under mechanical stimuli. Here, we demonstrate that photocrosslinking hydrogels on hydrophobic substrates leads to significant, long-lasting reductions in surface friction, ideal for cartilage tissue regeneration. Gelatin methacryloyl and hyaluronic acid methacrylate hydrogels photocrosslinked on polytetrafluoroethylene possess more hydrated, lubricious surfaces, with lower friction coefficients and crosslinking densities than those crosslinked on glass. This facilitated self-lubrication via water exudation, limiting shear during biaxial stimulation. When subject to intermittent biaxial loading mimicking joint movement, low-friction chondrocyte-laden neo-tissues formed superior hyaline cartilage, confirming the benefits of reduced friction on tissue development. Finally, in situ photocrosslinking enabled precise hydrogel formation in a full-thickness cartilage defect, highlighting the clinical potential and emphasizing the importance of crosslinking substrate in regenerative medicine.

The increasing demand for advanced in vitro models that replicate physiological crosstalk between cell types within and between organs requires customized cellular microenvironments arranged within a single platform. Hydrogels are biomaterials that mimic the physicochemical properties of tissue niches to optimally support diverse cell types. However, they require integration with cell patterning platforms like bioprinting or microfluidics to create organized multi-niche environments. There is currently a gap between bioprinting, which is scalable but limited by availability of printable hydrogels, and microfluidic patterning, which is compatible with diverse biomaterials but is challenging to multiplex. Here, we developed the Localized Microenvironment Well-Insert (LM-Well), a 3D-printed device designed to pattern multiple hydrogel niches with customizable physicochemical properties in multi-well plates. The LM-Well features patterning structures that enable capillary force-driven patterning of various hydrogel formulations, including natural, photo-crosslinkable and synthetic click hydrogels. Functional materials, exemplified by oxygen-scavenging microcapsules, can be patterned within the LM-Well offering an additional layer of control over local oxygen levels in individual cell niches, which modulated tumor growth and zonation of hepatic activities. Micro-architectural supports, such as micropillars or scaffolds, can be integrated into the LM-Well to optimally support mechanically-active cells like myocytes. The LM-Well's multi-niche patterning capability enabled the establishment of a liver-tumor co-culture in a single well, recapitulating altered drug efficacy on MCF-7 tumor cells following activation of tamoxifen and deactivation of doxorubicin by HepaRG-derived hepatocytes. As a versatile and accessible platform, the LM-Well facilitates physiologically relevant co-cultures with customizable niches and diverse biomaterials.

Science, technology, and innovation are related but distinct, leading to different research incentives. Incremental science, such as refining methods and validating findings, ensures robust results and understanding, laying the groundwork for breakthroughs. Due to pressures for ongoing innovation, fundamental research is frequently seen as an obstacle hindering scientific progress instead of an investment. The time fundamental research requires to bear fruit can detract from its immediate relevance, and impatience surrounding the urgency for rapid innovation further devalues the relatively slow, methodical approach of basic science. But this emphasis can be misleading, as many crucial advances arise from incremental improvements or refinements rather than radical breakthroughs. Insisting on scientific novelty devalues the work that lays the essential groundwork for reliable scientific progress and endorses a culture where only the most sensational achievements are celebrated, marginalising the essential contributions of those engaged in less glamorous, yet equally important, foundational research. We argue that instead of focusing on celebrating novelty and its often-unrealised societal impacts, science and technology should better value more vital basic, incremental, and knowledge-based contributions necessary for sustaining innovation and ensuring its diverse, positive impacts.

Osteosarcoma (OS) is the most common primary bone cancer in children and adolescents, with poor prognosis linked to metastasis and recurrence. Preclinical models that replicate human disease progression and the tumour microenvironment (TME) are critical for advancing therapies. We developed a novel orthotopic and humanised bone tumour microenvironment model in highly immunocompromised Il2rg and Rag2 double knockout rats. A humanised bone niche (HN) was established by implanting orthotopic humanised bone constructs (ohTEBCs) around the rat femur, followed by SaOS-2-luc cell injection. Longitudinal µCT and bioluminescent imaging tracked HN formation, tumour growth, and metastasis. Histological and immunohistochemical analyses revealed pathological mineralisation, extensive collagen deposition, tumour-specific ECM production, and neovascularisation within primary tumours and lung metastases. This model supports consistent engraftment of SaOS-2-luc tumours with robust metastatic spread, recapitulating key human OS features. It offers a translatable preclinical platform for studying OS progression and testing chemotherapy and surgical interventions.