Advanced Materials Interfaces

Surface functionalization of biomaterials enables the immobilization of proteins and other molecules and can be utilized to direct the biological response to devices and implants. Fetuin-A is a blood plasma protein involved in numerous physiological processes, including the regulation of mineralization. Notably, many investigations of fetuin-A have explored its cellular interaction when in solution, but limited studies report the role of fetuin-A when used as a surface modifier. The present investigation explores the response elicited by fetuin-A on Saos-2 cells when it is immobilized on a model gold surface through the covalent reaction with dithiobis(succinimdyl propionate) (DSP). Comparative surface characterization using x-ray photoelectron spectroscopy (XPS), atomic force microscopy - infrared spectroscopy (AFM-IR) and surface plasmon resonance (SPR) confirmed the surface modifications but indicate partial inhomogeneity in the functionalizer surface coverage. The interaction of albumin and fetuin-A with the surface was quantified by radiolabeling, quartz crystal microbalance with dissipation (QCM-D) and SPR, demonstrating a higher mass of fetuin-A bound to the surface in comparison to serum albumin. Over 7 days, cells bound to the surfaces with immobilized fetuin-A showed significantly hindered proliferation of osteoblast-like cells compared to the positive control (fibronectin), presumably due to a decrease in cell metabolism. This study provides new insights into the role of fetuin-A in regulating Saos2 cell response and elucidates its potential use in combination with chemical functionalizers for biomedical applications requiring surface modification.

Bio-based materials are known for their excellent biodegradability and, in some cases, their potential to fix carbon dioxide. Owing to these properties, they are increasingly being utilized as environmentally friendly alternatives across various applications. In this study, we focused on using living cells themselves as material components, aiming to evaluate their potential as substitutes for conventional plastic-based thermal insulators. We selected two types of cells, photosynthetic purple non-sulfur bacterium Rhodovulum sulfidophilum and tobacco BY-2 plant suspension cells. After optimizing solidification conditions through the addition of pectin and cellulose nanofibers, we measured the thermal conductivity of the solidified cells under atmospheric pressure. The results showed that R. sulfidophilum exhibited 0.0553 W/m{middle dot}K, while BY-2 exhibited a thermal conductivity of 0.043 W/m{middle dot}K. Both values indicate relatively low thermal conductivity compared to existing bio-based materials, suggesting high insulation performance. Among the solidified cells, the solidified BY-2 cells showed minimal variation in thermal insulation performance under pressure changes, and had a low thermal emissivity as revealed by FT-IR analysis. Based on these findings, we propose that cell-derived materials can serve as potentially biodegradable bio-based thermal insulation materials.

Osteoporotic bone degeneration involves progressive deterioration of trabecular microarchitecture, yet most scaffold-based bone tissue engineering studies evaluate osteogenesis in structurally favorable architectures that poorly represent compromised bone environments. Here, we establish a degeneration-inspired Voronoi scaffold platform in which point spacing serves as a single tunable architectural parameter to model transitions from dense mechanically integrated to severely deteriorated trabecular-like microenvironments. Increasing point spacing from 1.25 to 2.5 mm progressively reduced scaffold connectivity and stiffness while shifting deformation behavior from distributed load transfer to localized stress concentration, as confirmed by finite element analysis and mechanical testing. Benchmarking against clinically reported HR-pQCT datasets from postmenopausal women demonstrated that the intermediate 1.75 mm point spacing scaffold represents a clinically relevant compromised trabecular-like state, whereas the 2.5 mm scaffold represents a more severely deteriorated architectural condition. These architecture-dependent mechanical and structural transitions directly regulated hMSC behavior, where high point spacing scaffolds reduced cytoskeletal organization, stress fiber density, and osteogenic mineralization, establishing an architecture-associated osteogenic dysfunction regime. Polydopamine (PDA) coating progressively enhanced cytoskeletal organization and mineralization within architecturally compromised scaffolds without altering scaffold geometry. To quantitatively assess biointerface-mediated functional recovery, a Mineralization Rescue Percentage (MRP) framework was introduced, demonstrating up to 43% restoration of architecture-associated mineralization loss following PDA coating. Collectively, this work establishes a clinically contextualized degeneration-to-rescue biomaterials framework that shifts current scaffold design paradigms beyond structurally favorable architectures toward systematic investigation and functional rescue of architecture-associated osteogenic dysfunction within compromised bone-like microenvironments. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=79 SRC="FIGDIR/small/725650v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@26833forg.highwire.dtl.DTLVardef@72b2b7org.highwire.dtl.DTLVardef@333083org.highwire.dtl.DTLVardef@b5f2d1_HPS_FORMAT_FIGEXP M_FIG C_FIG Statement of SignificanceMost scaffold-based bone tissue engineering studies evaluate osteogenesis in structurally favorable architectures that poorly represent compromised bone microenvironments associated with osteoporosis. Here, a clinically contextualized Voronoi scaffold platform is established in which point spacing serves as a single tunable architectural parameter to model transitions from mechanically integrated to structurally deteriorated trabecular-like states. By decoupling architectural and surface biointerface effects, the study demonstrates that architectural deterioration alone can drive cytoskeletal disruption and osteogenic failure. Importantly, polydopamine-mediated surface engineering partially restored cytoskeletal organization and mineralization within architecturally compromised scaffolds without altering bulk geometry. A Mineralization Rescue Percentage (MRP) framework was further introduced to quantitatively assess biointerface-mediated functional recovery within degeneration-inspired scaffold microenvironments.

Sustainable, biodegradable elastomers are needed to replace fossil-based alternatives and reduce the environmental impact of traditional vibration damping materials. We investigate agarose-based hydrogels as eco-friendly vibration absorbers, examining the combined effects of polymer concentration (1-7 wt%), relative humidity (55-98%), and mechanical pre-stress on their dynamic mechanical properties. Frequency-dependent viscoelastic and vibration transmissibility tests, supported by Gaussian Process Regression (GPR), reveal that increasing agarose concentration enhances the storage modulus (E') by over an order of magnitude, reaching[~] 5 MPa depending on humidity and applied prestress. Remarkably, the damping efficiency--characterised by the loss factor (tan(d))--exhibits a highly non-monotonic trend. Maximum energy dissipation is observed at intermediate network densities, with tan(d) up to 0.21 and a loss modulus of[~] 515 kPa at 5 w% and 75% relative humidity, comparable to synthetic elastomers. GPR analysis shows that prestress controls nonlinear stiffening and transmissibility resonance behavior, while shifting peak damping from 5 wt% to 1 wt% agarose as prestress increases. These findings underscore the mechanical tunability and sustainability of agarose hydrogels, providing potential design guidance for biodegradable vibration mitigation materials.

Reliable and scalable soft implantable neural interface fabrication remains a key challenge for chronic bioelectronic applications. Here, we present a transparent soft microelectrode fabricated with electrohydrodynamic (EHD) printing, utilizing the fluorinated polymer poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and poly (3, 4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS) to form seamless, selectively patterned multilayer structures with low impedance and long-term stability. Controlled in situ curing during printing yields dense, void-free substrate and encapsulation layers, suppressing interfacial defects and ionic pathways, while maintaining high optical transparency (>60%) with PEDOT:PSS. The printed microelectrodes exhibit low impedance, high charge storage and injection capacities, and stable electrochemical behavior under biomimetic conditions. In addition, the devices demonstrate robust mechanical and electromechanical stability under cyclic deformation in both dry and wet environments, as well as under prolonged electrical stimulation. Accelerated aging studies project multi-year operational lifetimes, and in vitro/in vivo biocompatibility assessments confirm excellent tissue integration. These results establish EHD-printed fluorinated polymer-based microelectrodes as a scalable and durable platform for chronic implantable biointerfaces. ToC O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=182 SRC="FIGDIR/small/726391v1_ufig1.gif" ALT="Figure 1"> View larger version (79K): org.highwire.dtl.DTLVardef@152c58aorg.highwire.dtl.DTLVardef@126f1f5org.highwire.dtl.DTLVardef@1d743cforg.highwire.dtl.DTLVardef@1a4d743_HPS_FORMAT_FIGEXP M_FIG C_FIG This report presents an electrohydrodynamically printed transparent soft microelectrode for chronic purposes. Electrohydrodynamic printing promotes seamless multilayer structures with selective deposition and long-term mechanical stability. The devices show low impedance, high charge capacity, and robust electrochemical/electromechanical properties. Accelerated aging projects [~]7.2 year lifetimes, and XPS/SEM-EDS confirm strong ion barrier properties and biocompatibility for chronic implantation.

Traditional bioelectronic devices are limited by poor biointerfacing due to their substantial mismatch in mechanical and biochemical properties. In tissue engineering, soft and bioactive materials support biointegration by harnessing or mimicking the natural extracellular matrix (ECM). Building bioelectronic devices from ECM should improve their biointegration, yet there are limited methods to fabricate them due to current manufacturing approaches. An additive manufacturing strategy is presented here for collagen-based bioelectronic interfaces that integrates conducting polymer electrodes with ECM-based substrates or encapsulation layers. Addition of poly(ethylene glycol) diglycidyl ether (PEGDE) to poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) colloidal dispersions enables direct extrusion-based patterning under mild conditions compatible with collagen substrates, and forms aqueous stable and highly conducting printed patterns (2788 S m-{superscript 1}). The resulting interfaces maintain stable electrochemical performance over 7 days in physiological environments, and support primary human cell adhesion, viability, and proliferation across both material regions. A sacrificial patterning strategy using 3D printed cacao butter further enables spatial control of collagen encapsulation. This approach establishes a framework for fabricating functional bioelectronic devices based on ECM to further enhance device biointerfaces for tissue models and implantable systems.

Silver has been used as a biocide for centuries, mostly in health-oriented applications. However, as a biocide, silver is toxic not only to its intended targets, mainly bacteria and fungi, but also to all living cells. Because of this toxicity, it is desirable to use forms of silver that maximize the required biocidal activity while minimizing the amount of silver that will be released in the environment at the end of life of the product. Silver nano objects are a good compromise for such requirements. The high surface to volume ratio allows for good reactivity and thus good biocidal activity, while the small amount of silver present in nano objects allows for a limited environmental release at the product end of life. In this work, we tested three types of silver nano objects. The first type, polyvinylpyrrolidone-coated silver nanoparticles (nAg-PVP) were used as a control nanoparticle, as this type of nanoparticle is now widespread. We also manufactured and tested maltodextrin-coated silver nanoparticles (nAg-MD) and micrometric (20 {micro}m in two dimensions and a few nanometers in the third one) silver flakes ({micro}AgSF). For these three silver nano objects, we investigated the biocidal activity by stringent tests using both Staphylococcus aureus and Escherichia coli as target bacteria. In addition, we investigated toxicity on mammalian macrophages or keratinocytes cell lines, as well as on an insect hemocyte cell line. Our results showed that the two innovative silver nano objects (nAg-MD and even more {micro}AgSF), showed both a better bactericidal activity and a lesser toxicity than the reference nAg-PVP nanoparticles. In addition, we also checked that beyond toxicity, the silver nano objects did not induce an inflammatory reaction, making them safer to use.

Curcumin-functionalized gold nanoclusters are promising platforms for catalysis and drug delivery, yet the molecular determinants of their stability, morphology, and solvent response remain unclear. Here, microsecond all-atom molecular dynamics simulations are employed to investigate a 2 nm gold nanoparticle noncovalently coated with different curcumin forms, including neutral enol and trans-keto tautomers, the deprotonated enolate, and their mixtures in water-ethanol and water-methanol solvents. Layer-resolved analyses of radius of gyration, density profiles, and surface coverage reveal that neutral enol and trans forms generate compact assemblies with near-complete surface coverage, whereas enolate-rich systems adopt more expanded conformations with solvent-exposed molecules. Mixed systems preserve these intrinsic packing characteristics while improving overall coverage. Solvent substitution from ethanol to methanol reduces {pi}-{pi} stacking, strengthens Au-curcumin interactions, and increases surface coverage, yielding more compact nanostructures. Free energy and potential of mean force calculations indicate that deprotonated curcumin most effectively screens Au-Au interactions and stabilizes dispersed nanoparticles, while neutral tautomers provide moderate stabilization. Curcumin also enhances the loading of anticancer drug doxorubicin (DOX) onto Au nanoparticles, improving biocompatibility. Enolate(An)-containing systems produce extended structures with weaker membrane interactions, whereas neutral curcumin complexes form compact, positively charged assemblies that strongly bind to negatively charged cancer cell membranes. These findings clarify how tautomeric state and solvent environment cooperatively govern interfacial organization and colloidal stability, establish design guidelines for curcumin-based gold nanocarriers in catalysis, sensing, and drug delivery applications.

Over the past decade, the integration of microgel-based granular hydrogels in biomedical technologies has experienced substantial growth due to the numerous benefits microgels offer. However, the inability to easily adopt uniform microgel fabrication workflows at scale constitutes a major bottleneck, or in some cases, a barrier-to-entry that stunts further growth of the field. The gold-standard technique for emulsion-based microgel production is through microfluidic droplet-generating devices that produce liquid gel precursor droplets that gel post-production. However, traditional microfluidic workflows often require multiple independent flows and controlled pressure sources, along with a steep learning curve in using microfluidics to achieve uniform droplet sizes reproducibly and repeatedly. This difficulty in adopting microgel fabrication is further compounded by low throughput and the extensive flow rate calibration required when switching to new formulations (e.g., material type, droplet size). In this work, we present a step-emulsion system that bridges the gap by providing a robust and simple setup. We experimentally characterize and evaluate how flow and outlet channel dimension contribute to the generation of uniform droplet populations at specific sizes. With our large dataset consisting of various outlet channel dimensions, we evaluated outlet channel geometrical impacts (height, width, cross-sectional area, aspect-ratio, etc.) on gel precursor droplet size and generation throughput. We demonstrate robust, highly compatible, and repeatably uniform droplet generation from various gel precursor polymer backbones, users with varying microfluidics experience, and a wide viscosity range, including alginate solutions with 650 times the viscosity of water. Furthermore, we confirmed consistent gel precursor droplet generation outcomes driven by a constant flow source (syringe pump) and by direct manual injection as a simple and highly adoptable option for the generation of gel precursor droplets. This platform is ideal for researchers seeking rapid and easy microgel fabrication, regardless of microfluidics experience.

Paper-based diagnostics such as lateral flow assays (LFAs) and microfluidic paper-based analytical devices ({micro}PADs) have attracted considerable attention because of their low cost, portability, and ease of use. Currently, to enable fabrication of {micro}PADs and improve LFA performance, hydrophobic blocks are patterned on paper substrates. However, fabrication of high-resolution hydrophobic barriers remains a major challenge. In this work, we developed a novel silicone extrudable ink for the fabrication of hydrophobic features on paper substrates. The ink was formulated using a vinyl-terminated polydimethylsiloxane (vPDMS) and polymethylhydrosiloxane (PMHS) system crosslinked through platinum-catalyzed hydrosilylation, and its rheological properties were tailored by incorporating silica fillers, obtaining a shear-thinning gel suitable for extrusion. The resulting formulation provided tunable properties, controlled deposition, and stable feature formation, enabling simple, low-cost, rapid, and robust fabrication of high-resolution hydrophobic barriers. Using this approach, we demonstrated improved fluid confinement and pattern fidelity on paper substrates, fabricated high-resolution paper microfluidic devices down to 150 {micro}m channel width, and enhanced the sensitivity of an LFA for a malaria diagnostic test. These results highlight the potential of this silicone ink platform as a practical and scalable strategy for advancing high-performance paper-based diagnostic technologies.

Nanoclay-based biomaterials offer promise for localised growth factor presentation, yet their in vivo degradation, clearance, and systemic fate remain poorly defined. Here, we investigate the fate of a synthetic nanoclay-BMP-2 gel during ectopic bone induction using a combination of in vivo imaging, histology, and component-resolved elemental analysis. Fluorescent tracking confirmed prolonged localisation of BMP-2 within the nanoclay gel and robust bone induction despite negligible growth-factor release. Inductively coupled plasma mass spectrometry (ICP-MS) revealed divergent clearance kinetics for lithium and silicon, structurally distinct components of the clay crystalline lattice, indicating decoupled ionic and particulate degradation pathways. Early clearance was dominated by cell-mediated fragmentation and the transport of clay particulates, while later stages involved preferential lithium release associated with local clay dissolution as well as integration within newly formed bone. Systemic biodistribution analysis demonstrated rapid, transient lithium release into circulation with renal clearance, contrasted with initial hepatic and then later-phase renal handling of silicon species. Together, these findings define a multiphasic in vivo clearance model for nanoclay biomaterials consistent with progressive remodelling, localised BMP-2 activity and, importantly, safe systemic handling. This work provides mechanistic insight into the activity and clearance of nanoclay-based regenerative therapies and establishes the importance of component-resolved tracking for evaluating the biodistribution of degradable inorganic biomaterials.

Cryopreservation offers an option for long-term storage and global distribution of complex in vitro models, yet protocols for multicellular microphysiolgocial systems (MPS) such as brain organoids/spheroids remain limited. Here, we systematically compared three commercially available cryopreservation (mFreSR, CryoStorCS10, and 3dGRO) and two freezing time points, and established a robust workflow for freezing and recovering brain organoids. After defrosting, we assessed morphology and metabolic activity. We also evaluated electrophysiology, calcium transients, and neurite outgrowth. In addition, we measured astrocyte migration, apoptosis, mitochondrial integrity, microglia survival, and neural marker expression. We found that organoids require a 4-week recovery period to regain structural and functional stability. Although organoids frozen at week 6 showed higher metabolic activity after recovery, organoids cryopreserved at week 2 had clearly better functional outcomes. They exhibited stronger spontaneous network firing and maintained calcium transients. Finally, incorporated microglia-like cells survived the freezing and displayed comparable morphology to unfrozen controls. Across the endpoints measured here, 3dGRO showed the most favorable overall performance; formal ranking across media awaits harmonized normalization, single-organoid electrophysiology, and prespecified QC thresholds. Together, these results define a practical and reproducible cryopreservation strategy that preserves key physiological features of brain organoids and supports the establishment of ready-to-use organoid banks. The ability to reliably store and distribute complex brain-like tissues represents an essential step toward global standardization, scalable experimentation, and wider adoption of human-relevant microphysiological systems. Together, these results demonstrate recovery of key physiological features in the subset of organoids that remain viable after thaw and support the feasibility of brain organoid banking.

Various ankle-foot conditions (e.g., fractures, diabetic foot ulcers, and post-surgical recovery) require periods of complete non-weightbearing followed by gradually increasing partial loadings. However, existing assistive devices often provide inconsistent or uncomfortable offloading during gait. Additionally, prolonged proximal leg offloading can contribute to muscle atrophy, reduced bone density, and overuse of other body segments. We present a novel offloading ankle-foot orthosis (OLAFO) designed to overcome these limitations. The OLAFO features a patient-specific load-bearing shank brace, designed through a digital workflow and fabricated from a 3D-printed core reinforced with carbon-fiber composite lamination. Interlocking serrated side struts, adjustable in 2 mm increments, modulate load sharing between the shank and plantar surfaces. Furthermore, the OLAFO incorporates contact plates with a rocker profile informed by roll-over-shape measurements to support forward progression and gait symmetry. Proof-of-concept biomechanical verification in one able-bodied participant evaluated complete offloading, five partial-loading levels, and normal gait using a pressure walkway to compute vertical ground reaction forces and impulses. In complete offloading, the affected foot generated no contact pressures. Across partial-loading levels, the foot impulse increased from 14% to 53% of the total load and scaled linearly with strut height adjustments, supporting clinician-prescribed loading increments. Contralateral stance duration increased only modestly compared to commonly used assistive devices, indicating reduced compensatory loading on the intact limb. These findings demonstrate the proof-of-concept feasibility of the OLAFO, highlighting its potential for verifying full offloading and prescribing partial-loading targets during rehabilitation. Future research will evaluate performance across patient populations and clinical rehabilitation tasks.

Sustainable synthesis of photoluminescent nanomaterials with tuneable surface chemistry and defined biological activity remains a central challenge in green nanoscience. Here we show that the energy-input route used to carbonise a single bearberry (Arctostaphylos uva-ursi) extract precursor system exerts a decisive and mechanistically coherent influence over the surface chemistry, optical performance, and bioactivity of the resulting carbon quantum dots (CQDs). Hydrothermal processing (160 {degrees}C, 6 h) yields particles of 7.13 nm hydrodynamic diameter enriched in surface hydroxyl and carbonyl groups, a higher graphitic sp{superscript 2} carbon fraction (43.06%), and potent DPPH radical scavenging activity. In contrast, microwave-assisted synthesis yields 9.65 nm particles with a higher surface carboxylate content (O-C=O: 19.06%), enhanced fluorescence quantum yield, and increased intracellular uptake. Uptake is statistically significant in retinal epithelial cells at 200 {micro}g/mL (p < 0.001) and shows concentration-dependent accumulation in zebrafish larvae from 100 {micro}g/mL (p < 0.05). Combined XPS C 1s deconvolution and FTIR difference spectroscopy indicate that incomplete decarboxylation under microwave conditions underlies these distinct properties. Both formulations maintained full cytocompatibility across 10-250 {micro}g/mL in both RPE-1 and HeLa cells, with no statistically significant reduction in viability at any tested concentration. These findings define a synthesis-route-encoded structure property relationship that enables rational selection between antioxidant-optimised and imaging-optimised CQD formulations from an identical green precursor system.

Hydrogels are the preferred materials for applications mimicking soft tissues due to their high water content and tunable mechanical properties. The state of the water in these hydrated networks governs their response to mechanical loading through coupled interstitial flow and large deformations of the solid network. Reliable experimental methods for quantifying the fraction of mobile fluid during mechanical deformation remain limited. Within the theoretical framework of mixture theory, we describe hydrogels as hydrated biphasic media consisting of a deformable incompressible solid matrix and a mobile fluid phase. We developed a mechanical testing protocol that enables the experimental separation of solid and fluid contributions under loading. The method is demonstrated using biocompatible and highly versatile hydrogel phantoms of varying compositions. Controlled, incremental drained confined compression of the hydrogel samples results in free-water fractions of approximately 40%, 60%, and 77%, reflecting the systematic influence of the polymer content on the porosity and fluid mobility. Comparison with cryo-SEM-derived surface porosity reveals statistically significant differences and highlights the scale-dependent sensitivity of surface measurements compared to bulk measurements. This study introduces a new mechanical method for quantifying the free-water fraction in macroporous, ultrasoft, highly hydrated biomaterials. Furthermore, the multi-step protocols enable the separation of dissipative, fluid-related relaxation from the equilibrium response of the solid skeleton, allowing direct calibration of constitutive models for macroporous soft solids. The proposed method provides a reliable basis for the development and optimization of hydrogels for applications where fluid transport is critical, such as neural interfaces, bioelectronic platforms, and tissue-engineered constructs.

BackgroundBone graft biomaterials play a critical role in bone regeneration by influencing osteoblast differentiation and mineralization. However, comparative data regarding the osteogenic potential of commonly used graft materials under standardized conditions remain limited. Method and materialIn this in vitro experimental study, osteoblast-like cells (MG-63) were cultured with four bone graft materials, including Bio-Oss, Cerasorb, Bio-Tiss Cerabone, and Pro Osteon. The relative mRNA expression of osteogenic markers (COL1 and OPN) was evaluated at 1, 7, 14, and 21 days using real-time PCR. Alkaline phosphatase (ALP) activity and mineralization capacity were also assessed using colorimetric assay and Alizarin Red staining. Data were analyzed using one-way ANOVA and Tukey post hoc test (P < 0.05). ResultsSignificant differences were observed among the tested materials across all evaluated parameters. Bio-Oss and Cerasorb demonstrated higher gene expression levels and ALP activity compared to Bio-Tiss Cerabone and Pro Osteon (P < 0.05). Mineralization analysis showed significantly greater calcium deposition in the Bio-Oss and Cerasorb groups, whereas Pro Osteon consistently exhibited the lowest osteogenic performance. ConclusionBone graft biomaterials significantly influence osteogenic activity in osteoblast-like cells. Bio-Oss and Cerasorb showed superior osteogenic potential, while Pro Osteon demonstrated weaker performance. These findings highlight the importance of material properties in optimizing bone regeneration.

Hydrogels are widely used as three-dimensional cell culture systems to understand the impact of cellular mechanotransduction for tissue engineering applications. Photoinitiated thiol-ene click chemistry is a commonly utilized hydrogel crosslinking mechanism that provides spatial and temporal control over hydrogel network formation and resulting mesh size and compressive properties. Despite historically documented efficiency as step-growth reactions, these reactions do not always proceed as predicted. To understand the impact of cell confinement and microenvironmental mechanics on cellular function, thiol-ene network formation must be thoroughly characterized. To this end, the objective of this work was to investigate the crosslinking dynamics to determine hydrogel network formation as assessed via mesh size and mechanical properties using a pentenoate-functionalized hyaluronic acid thiol-ene reaction. Hydrogel parameters including polymer concentration and thiol:-ene crosslinker molar ratio were modulated (4, 6, or 8 polymer weight percent and 0.15:1, 0.5:1, or 1:1 molar ratio of thiol groups to reactive -ene groups) to tune network properties including shear storage modulus and relative mesh size. Molecular Dynamics (MD) simulations were used to simulate the thiol-ene crosslinking reaction and establish a method for predicting thiol-ene reaction efficiency. Lastly, the feasibility of this hydrogel system for in vitro modeling was confirmed via assessment of metabolic activity of encapsulated primary human meniscal cells.

Surface functionalization of inorganic quantum dot nanoparticles is of great interest in the application of these materials toward a wide range of biological applications where membrane interactions are critical. The use of amphiphilic lipids to functionalize the surfaces of quantum dots represents a promising alternative to produce water-soluble and membrane-active materials with facile tuning of the quantum dots surface properties. Here, we demonstrate an experimental approach that yields lipid-coated quantum dots with highly tunable surface charge by controlling the concentration of cationic lipids during preparation. Through fluorescence-activated cell sorting assays, we show that these cationic lipid-coated quantum dots can enhance membrane interactions and increase membrane labeling density in live HEK293 cells. We further employed coarse-grained molecular dynamics simulations to model the lipid self-assembly process using an implicit solvent force field and subsequently model the adsorption of lipid-coated quantum dots to model membranes. Our simulations show that we can control the effective surface charge of lipid-coated quantum dots and influence the strength of adsorption to oppositely charged lipid membranes, a process that is mediated by the release of counterions at the quantum dot-membrane interface. This work supports the future development of biocompatible and water-soluble inorganic nanoparticles with highly tunable surfaces, and provides mechanistic insight into how different lipids can influence nanoparticle-membrane interactions at a molecular scale.

Postoperative gastric leak after bariatric surgery is a serious complication associated with prolonged treatment, repeated interventions, and substantial morbidity. Endoscopic internal drainage using double pigtail stents is widely adopted. However, current stents, originally designed for biliary use and often based on simple cylindrical geometries, are not optimized for post-bariatric gastric leak anatomy, mechanical support, or fluid drainage. Here, we present BRIDGE (Biodegradable aRchitected Internal DrainaGE), a stent concept integrating triply periodic minimal surface (TPMS) architectures to control mechanical compliance, kink resistance, and drainage performance. Using computational modeling, mechanical testing, and benchtop flow studies, we evaluate TPMS designs and identify volume fraction as a key parameter balancing flexibility, structural integrity, and hydraulic performance. TPMS-integrated designs tolerated a 7.1-fold smaller bend radius than a commercial stent without kinking and achieved up to a 2-fold increase in drainage. We also developed a stereolithography-printable biodegradable resin and fabricated a prototype lattice-integrated stent. TeaserA biodegradable, 3D-printed stent with an architected lattice design improves flexibility, kink resistance, and abscess drainage while eliminating the need for device removal.

Cultivated meat is an emerging biotechnology that aims to produce edible tissues in an ethical and sustainable manner. However, the recreation of skeletal muscle tissue that replicates the protein composition and sensory characteristics of traditional meat is a major challenge. Skeletal muscle tissue engineering requires non-animal-based scaffolds which are inexpensive and food-safe, while meeting specific mechanical requirements with respect to viscosity, stress-relaxation and stiffness. While many of these characteristics can be fulfilled by alginate-based biomaterials, a key limitation of alginate is its lack of intrinsic attachment sites for animal cells, preventing efficient adhesion, differentiation and tissue formation. Here, we established a screening platform to evaluate extracellular matrix (ECM)-mimicking peptides as functionalisations of alginate scaffolds in 2D. Our platform enables high-throughput assessment of cell/peptide interactions, serving as a predictive tool for 3D tissue constructs. Our screen identified two RGD-containing sequences (vitronectin- and fibronectin-mimicking peptides) as most effective in promoting attachment and myogenic fusion of bovine satellite cells. Notably, these peptides outperformed more complex mixtures containing up to seven different ECM-mimicking peptides. Our findings provide a streamlined approach for optimising biomaterial functionalisations for cultivated meat applications, and lay the groundwork for future advancements in scalable, sustainable skeletal muscle tissue engineering.