Advanced Healthcare Materials

Biomaterials-based tissue engineering aims to recapitulate native tissue architecture and function for both clinical repair and advanced in vitro models. While improvements in biomaterials have been made, including granular hydrogels and ECM-derived scaffolds, current biomaterials lack intentional design choices for effective translation, including regulatory considerations, practical extrusion delivery, and biomimetic characteristics. Here, we develop and characterize a library of granular ECM (gECM) biomaterials for five key tissues (cartilage, bone, skin, liver, and kidney), in which ECM particles are densely packed within a hyaluronic acid hydrogel. We optimize tissue processing methods that preserve proteomic content and structure while also aligning with scale-up manufacturing and regulatory guidelines. We show that gECM hydrogels can be molded, extruded, and 3D-printed while retaining their shape, and they stabilize at physiological temperature and pH. Lastly, we demonstrate that bulk gECM mechanics are driven by tissue type, and gECM hydrogels support viability, proliferation, and tissue-specific cellular activity. Together, these findings establish gECM hydrogels as a translational and biomimetic platform for clinical tissue repair and complex in vitro models.

Focal injuries to articular cartilage in load-bearing joints fail to heal and often progress to degeneration, underscoring the need for repair strategies that result in restored cartilage structure and function rather than fibrocartilage formation. Granular extracellular matrix (gECM) hydrogels, flowable grafts composed of densely-packed matrix particles, offer a promising approach but lack long-term functional validation in large-animal models. Here, we developed a flowable gECM hydrogel composed of decellularized cartilage microparticles incorporated within a thiol-functionalized hyaluronan matrix. Proteomic analysis confirmed enrichment of cartilage-specific gECM matrisome components. When implanted into critical-sized femoral condyle defects in a goat model and evaluated 12 months post-implantation, both gECM hydrogel and microdrilling (surgical controls) achieved >80% defect filling. However, in contrast to microdrilling, gECM repair tissue exhibited surface tribological (friction, adhesion) and compressive mechanical properties comparable to native cartilage, with a similar proteoglycan-to-collagen ratio, enrichment of type II collagen, minimal type I collagen (typical of a fibrous scar), improved quantitative MRI metrics, and evidence of lateral cartilage integration and subchondral bone remodeling. Together, these findings demonstrate that a flowable gECM hydrogel supports integrative, cartilage-like repair in a load-bearing joint, supporting advancement of this approach toward clinical translation. One Sentence SummaryA granular ECM hydrogel implanted in a goat condyle provided a robust repair, filling the defect tissue with integrated, hyaline-like cartilage at 12 months.

Critical-sized bone defects and implant-associated complications are often exacerbated by chronic inflammation, which compromises tissue repair and implant integration. Mesenchymal stromal cell (MSC)-derived extracellular vesicles have emerged as promising immunomodulatory nanotherapeutics; however, their clinical translation remains constrained by low yield, heterogeneity, and poor scalability. Here we present a bioengineered MSC-derived nanoghosts platform designed to overcome these translational barriers while enabling tunable osteoimmunomodulatory function. By coupling high-yield nanoghost fabrication with biomimetic MSC conditioning, we demonstrate that oxygen tension (5 or 21% O2) and 3D culture substrates (5 or 15 wt-% GelMA) can reprogram MSC immunophenotype. Nanoghosts generated under hypoxic and 3D conditions displayed enriched anti-inflammatory cargo, preserved MSC viability under inflammatory stress, and partially rescued osteogenic mineralization in the presence of pro-inflammatory cytokines. Together, these findings showcase MSC nanoghosts as scalable and bioactive immunoregulatory nanotherapeutic capable of modulating immune-bone crosstalk, providing a translational strategy to mitigate inflammation-driven impairment of bone regeneration and implant integration. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=90 SRC="FIGDIR/small/724218v1_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@1551655org.highwire.dtl.DTLVardef@12d3371org.highwire.dtl.DTLVardef@8c50bborg.highwire.dtl.DTLVardef@834a8_HPS_FORMAT_FIGEXP M_FIG C_FIG

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.

The plasticity of dendritic cell (DC) functional state is a major hurdle in DC therapy, yet how DCs acquire distinct states independent of ontogeny remains poorly understood. Here, we demonstrate that changes in matrix stress relaxation mechanically educate DCs to adopt distinct, persistent functional states even after the removal of mechanical cues. Stem cell-derived DCs cultured in a fast-relaxing environment exhibited enhanced antigen presentation, faster migration, and higher expression of T cell-recruiting chemokines. Slow-relaxing DCs, biased towards pro-inflammatory cytokine secretion, were enriched for gene signatures associated with lipid accumulation and stress response. These mechanical responses were conserved across human and murine DCs. Using ovalbumin (OVA) as the model antigen, fast-relaxing DCs elicited a CD8+-biased response in vitro, with higher antigen-specific CD8+ T cell activation and proliferation. In vivo adoptive cell transfer of mechanically educated DCs demonstrated that the fast-relaxing matrix licensed DCs to induce a potent draining lymph node T cell response with more antigen-specific T cells and higher restimulation potential. We further showed that DCs sensed matrix stress relaxation through PI3K signaling and actin branching, mediated by the concerted signaling of IL-4 and GM-CSF. Together, these findings demonstrate the role of matrix stress relaxation on the functional state of DCs and suggest a novel approach to enhance ex vivo cellular engineering by targeting mechanical signaling. Graphical AbstractStem cell-derived dendritic cells (DCs) generated ex vivo are engineered using biomaterial platform with tunable matrix stress relaxation. Mechanical education of DCs is licensed by cytokine signaling, actin branching, and PI3K signaling. Fast-relaxing DCs exhibit higher antigen presentation and faster migration, which enhances their capacity to prime and activate antigen-specific CD8+ T cells. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=81 SRC="FIGDIR/small/725170v1_ufig1.gif" ALT="Figure 1"> View larger version (18K): org.highwire.dtl.DTLVardef@bb6709org.highwire.dtl.DTLVardef@1698c8eorg.highwire.dtl.DTLVardef@8adb0dorg.highwire.dtl.DTLVardef@336d3a_HPS_FORMAT_FIGEXP M_FIG C_FIG

This study focuses on the development of 3D culture model dedicated to liquid cancers drug screening. The challenge addressed was to effectively retain non adherent small cells within a 3D-scaffold with tailorable mechanical properties, while proposing a fast and effective tool for drug screening. To that aim, we developed a macroporous alginate-chitosan polyelectrolyte complex (PEC) scaffold combined with a low-viscosity alginate (LVA) cell seeding solution. We hypothesized that LVA could undergo in situ pore gelation via calcium ions retained from the PEC fabrication process, enabling effective retention and homogeneous cell distribution, leading to an improved platform for drug screening and personalized medicine. First, we evaluated scaffold suitability for LVA infiltration and gelation. Microtomography revealed a highly porous architecture (98%) enabling LVA homogeneous penetration and complete gelation within 30 min, as confirmed by SEM, microscopy, rheology, and micro-rheology. Next, we assessed cell retention and biocompatibility using primary human chronic lymphocytic leukemia (CLL) cells. LVA-assisted seeding increased cell density 2.6-fold compared to medium alone, with homogeneous distribution, >80% viability over 7 days, and preserved differentiation into nurse-like cells. Finally, we demonstrated a proof of concept for drug screening. The Alginate-PEC scaffold (A-PEC scaffold) supported both qualitative live/dead imaging and rapid quantitative viability measurement with the Alamar Blue assay. Drug responses reproduced microenvironment-dependent protection effects observed in vivo. This integrated scaffold and seeding method provides a promising 3D platform for in vitro liquid cancer studies and drug screening on patient-derived hematological cancer cells. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=67 SRC="FIGDIR/small/722037v1_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@9b71d4org.highwire.dtl.DTLVardef@14e1dd0org.highwire.dtl.DTLVardef@1876a56org.highwire.dtl.DTLVardef@15656bc_HPS_FORMAT_FIGEXP M_FIG C_FIG

Critical-sized bone defects represent a challenge in bone tissue engineering, due to insufficient vascularization that results in implant failure. Scaffold pre-vascularization is a promising strategy to create a functional microvascular network that integrates with host vasculature. In this study, we present a hybrid 3D construct comprising a hyaluronic acid-based hydrogel and a 3D printed polycaprolactone/{beta}-tricalcium phosphate scaffold, to support vascular network formation and osteogenic differentiation. Peptide-functionalized (i.e. RGD, YIGSR, IKVAV, QK) hydrogels were obtained via thiol-ene chemistry, using two crosslinkers (PEG-diSH or MMP-diSH). Preliminary biological experiments assessed human mesenchymal stromal cells (hMSCs), endothelial cells (hUVECs), and their co-culture, on different gel formulations. All cell conditions displayed enhanced spreading and metabolic activity on gel formulations comprising RGD; thus these (i.e. RGD only and a combination of RGD/YIGSR) were selected for further studies. Cells were then mixed with the hydrogel precursor solutions, which were injected to embed the scaffolds and crosslinked using a UV lamp. After 7 days, tubule formation was observed only in co-culture conditions, highlighting the importance of cellular crosstalk for the formation of a vascular network. Significant differences were found across the tested formulations. In the RGD-PEG constructs, hUVECs formed tubule-like structures, surrounded by hMSCs, exhibiting pericyte-like behavior, supported by the upregulation of SMA gene. Conversely, in the RGD/YIGSR-MMP conditions, hMSCs were mostly located on the scaffold fibers, and showed the highest expression of early osteogenic markers (RUNX2 and ALP). Overall, we demonstrated that the hybrid system with tailored hydrogel chemistry can support simultaneous microvascular organization and osteogenic commitment, offering a promising platform for bone tissue engineering applications. However, further studies involving longer culture periods will aim at clarifying the complex interplay between material composition, cell crosstalk and spatial organization and their influence on the maturation and stability of the vascular network.

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.

Interleukin-4 (IL-4) is a key immunoregulatory cytokine that promotes type 2 inflammation, drives macrophage polarization toward an anti-inflammatory M2 phenotype, and supports tissue repair. However, clinical translation of IL-4 therapies to modulate the immune response is limited by the need for precise control over its delivery to avoid immune dysregulation. Here, we report an affinity-based strategy to modulate IL-4 delivery and bioactivity using engineered affibody proteins. A yeast surface display library was screened via magnetic- and fluorescence-activated cell sorting to identify two IL-4-specific affibodies with moderate binding affinities (dissociation constants, KD = 459 and 141 nM). Circular dichroism confirmed expected alpha-helical folding, and biolayer interferometry characterized the kinetics of IL-4 binding. Structural modeling using AlphaFold3 and RosettaDock and molecular dynamics simulations using GROMACS predicted distinct binding sites for each IL-4-specific affibody on the IL-4 protein and suggested potential interference with receptor complex formation. Bioactivity studies using murine bone marrow-derived macrophages demonstrated that IL-4 complexed with affibodies maintained Ym1 gene expression but significantly reduced Ym1 protein levels, indicating partial inhibition of IL-4 signaling. To enable controlled cytokine delivery via affinity interactions, affibodies were conjugated to polyethylene glycol maleimide (PEG-mal) hydrogels, which were loaded with IL-4. Affibody-conjugated hydrogels achieved high IL-4 loading efficiency (>90%) and exhibited sustained release over 7 days. Increasing affibody-to-IL-4 ratios significantly reduced both the rate and total amount of cytokine release. Overall, this work establishes IL-4-specific affibodies as versatile tools for tuning cytokine presentation and modulating bioactivity and provides a promising approach for regulating inflammatory responses and advancing cytokine-based therapies with improved temporal control. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=163 SRC="FIGDIR/small/723637v1_ufig1.gif" ALT="Figure 1"> View larger version (46K): org.highwire.dtl.DTLVardef@12bdb14org.highwire.dtl.DTLVardef@3c09eeorg.highwire.dtl.DTLVardef@1b00934org.highwire.dtl.DTLVardef@2c4840_HPS_FORMAT_FIGEXP M_FIG C_FIG

Ancestry-associated immune differences influence fibrosis risk, however, how fibrosis-associated pathways vary across individuals remains poorly understood. Fibroblasts are a main cell type involved in fibrosis. The fibroblast response is shaped by cytokine signaling and macrophage activation. The extent to which these pathways vary across individuals, and how ancestry-associated immune differences influence fibrosis risk, remains poorly understood. Here, a poly(ethylene glycol) (PEG)-based hydrogel microphysiological system was leveraged to model fibroblast-macrophage interactions following oxidative stress and to integrate donor-specific immune signals using matched macrophages and serum. Individuals of self-reported African ancestry exhibited higher monocyte expression of CCL4, lower monocyte expression of OXER1, and increased serum IL-10, compared to individuals of European ancestry. Within the hydrogel, oxidative stress reduced fibroblast prevalence while inducing Ki67 and p16. Exogenous TGF-{beta}1 increased fibroblast prevalence and collagen 3 production but did not independently increase -SMA. Incorporating donor-specific macrophages and serum revealed that cultures from individuals of European ancestry demonstrated higher fibroblast -SMA and p16 expression. Pharmacologic inhibition of IL-10 further increased -SMA, particularly in African ancestry-derived cultures, identifying IL-10 as a key protective signal limiting fibroblast activation. This hydrogel system provides a platform for dissecting inter-individual immune variation and identifying mechanisms underlying ancestry-associated fibrosis risk.

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.

Cancer is a significant contributor to global mortality and places a substantial burden on healthcare systems, underscoring the need for improved strategies for developing and evaluating new therapies. Electrochemical impedance monitoring of in vitro cancer models is a promising technique for evaluating treatment effectiveness, particularly for evaluating how well a drug may kill cancer cells. This approach is advantageous over conventional end-point assays because it is non-destructive, label-free, and can provide temporal information on cell behavior and drug kinetics. However, traditional impedance devices are limited in that they do not support three-dimensional cell culture that has become standard in cancer studies. Typical devices are planar substrates that support monolayer culture, which has been shown to overestimate drug effectiveness. In this work, we propose 3D printed bioelectronic scaffold devices that provide 3D cancer cell culture while functioning as an on-chip readout for monitoring changes in cell characteristics via impedance. We describe device development and demonstrate reproducible fabrication, stable electrochemical properties, cell detection by impedance, and proof-of-concept monitoring of cytotoxicity in response to a chemotherapeutic drug. Overall, this technology offers a promising platform that could be further developed for compound screening as part of drug development or precision medicine.

The combination of synthetic biology and additive manufacturing has driven major changes in production of biomaterials, especially through the use of three-dimensional (3D) bioprinting to create engineered living materials. However, current fabrication methods can be limited by prohibitive hardware costs and the inability to maintain structural fidelity in complex, free-form living architectures. This work demonstrates how to build a low-cost, open-source 3D bioprinting platform that can make complicated bacterial structures with complex geometry and high dimensional accuracy. A commercially available, conventional fused deposition modeling 3D printer was modified to create a bioprinting system that is simple to build. The modified bioprinter, which costs around $450, is less expensive than many commercial bioprinters. This 3D-printing technology uses slurry-based support bath methods featuring low-cost gelatin and agarose microparticles, resulting in structures with a high aspect ratio (>8:1) and feature sizes as small as 260 m. The optimization of critical printing settings, including the ability of the bioink to retract during non-print movements, resulted in a reduction of unwanted bacterial deposition by nearly two orders of magnitude. Long-term viability experiments showed that bacteria in the bioprints could survive for at least 28 days with nutrient supplementation. Additionally, 3D-printed engineered biofilms revealed that incubation conditions and extracellular matrix composition significantly impacted the mechanical properties of printed constructs, with tradeoffs between matrix production and mechanical integrity. This study showcases an accessible 3D bioprinting platform for advanced bioprinting technologies, enabling development of engineered living materials with potential applications in synthetic biology, biotechnology, and tissue engineering.

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.

Therapeutic cancer vaccines represent a promising approach to boost patients own immune system to fight cancer. However, many vaccine candidates have shown limited success in clinical trials in large part due to the insufficient antigen delivery to overcome tolerance and hypoxia mediated immunosuppressive mechanisms. Cryogel-based delivery scaffolds have emerged as a promising platform for cancer vaccines due to their biocompatibility and macroporous structure that allows for effective delivery to infiltrating antigen-presenting cells. However, these systems are limited by rapid, diffusion-mediated burst release of encapsulated recombinant proteins and local hypoxia-driven immunosuppression within the scaffold. Herein, we demonstrate that click conjugation of a tumor-associated protein within cryogel-based vaccines, combined with our new O2-generating platform (Click O2-CryogelVAX), helps overcome immune suppression and weak antigenicity and primes effective anti-cancer immune responses. Sustained antigen delivery promotes cellular memory and Th1-mediated anti-cancer responses. By reversing hypoxia-driven immunosuppression, O2 acts as a powerful co-adjuvant to enhance humoral immunity. Together, Click O2-CryogelVAX supports a robust antitumor response that inhibits tumor growth and prolongs survival in a therapeutic prostate cancer model. These findings support the further research and development of Click O2-CryogelVAX as an effective delivery platform for therapeutic cancer vaccines.

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.

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.

The transplantation of stem cell-derived extracellular vesicles (EVs) holds promise for tissue repair and regeneration, but scalable production and effective delivery to target tissue remain major challenges. Here, we present a biomaterial platform that combines high-yield, scalable nanovesicles (NVs) - EV mimetics derived from human induced pluripotent stem cells - with an adhesive silk hydrogel patch for localized and sustained delivery. We show that this platform enables efficient NV encapsulation via visible light crosslinking and supports controlled release over short (2 days), intermediate (7 days), and extended (up to 28 days) periods, while maintaining adhesion to heart tissue. Importantly, the sustained delivery of NVs for 3 days in vitro results in promoting anti-fibrotic cell remodeling and significant functional recovery of primary myofibroblast activation, modulating integrin signaling, actomyosin organization, and cell-matrix adhesion networks. Finally, we demonstrate biocompatibility, retention, and anti-fibrotic function of the patch in a murine ischemia-reperfusion injury model. Thus, we establish the proof-of-principle that di-tyrosine silk hydrogels can be used as a strategy to encapsulate and deliver NVs to the heart, thus offering an innovative delivery platform for NVs. Statement of significanceExtracellular vesicles (EVs) represent an emerging frontier in tissue engineering. Their cell-specific cargo contains biological information capable of repairing and regenerating injured tissues. However, their clinical translation is hindered by limited manufacturing scalability, undefined dosing and modes of administration, and low organ retention, particularly in the heart. This study addresses these challenges by combining stem cell-derived nanovesicles (NVs), which mimic biological EVs, with an adhesive hydrogel patch for localized and sustained delivery to the heart. We provide proof-of-principle that di-tyrosine photo-crosslinked silk hydrogels are a suitable delivery platform for cell-derived NVs, preserving NV bioactivity and their ability to remodel recipient cells following delivery both in vitro and in vivo. This study integrates three key advantages: (i) the use of scalable iPSC-derived nanovesicles as an EV-mimetic platform, addressing limitations in EV manufacturing; (ii) a mechanically robust and tunable silk fibroin hydrogel formed via visible light-induced di-tyrosine crosslinking without chemical modification; and (iii) an injection-free, adhesive patch-based delivery strategy enabling localized and sustained therapeutic administration to the heart. This innovative platform represents a significant advancement in the fields of nanomedicine and biomedical engineering. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=108 SRC="FIGDIR/small/722555v1_ufig1.gif" ALT="Figure 1"> View larger version (26K): org.highwire.dtl.DTLVardef@fed253org.highwire.dtl.DTLVardef@1a270b0org.highwire.dtl.DTLVardef@19437c1org.highwire.dtl.DTLVardef@1d863ca_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical abstractC_FLOATNO C_FIG

Pathologic arterial stiffening is a hallmark of vascular disease that contributes to maladaptive vascular remodeling and neointimal hyperplasia through vascular smooth muscle cell (VSMC) phenotypic switching. Yet, because vascular disease progression is governed by both biomechanical and extracellular matrix (ECM) alterations, existing in vitro models often fail to recapitulate the full complexity of the diseased vascular microenvironment. Here, we developed a bioactive decellularized extracellular matrix (dECM) and methacrylated hyaluronic acid (MeHA) composite scaffold platform with tunable stiffness that preserves native vascular ECM components while enabling controlled investigation of stiffness-dependent cell behavior. Proteomic analyses confirmed retention of key vascular matrisome components, including collagens and glycoproteins, following decellularization. Electrospun vascular dECM scaffolds maintained an aligned fibrous architecture and spanned stiffness ranges representative of healthy and pathologically stiffened arterial microenvironments. Within this matrix-preserving platform, human VSMCs cultured on stiff dECM scaffolds exhibited increased spreading, altered morphology, enhanced nuclear localization of YAP and survivin, and broad transcriptional changes consistent with a shift toward a proliferative, matrix-remodeling VSMC phenotype. Together, this bioactive, matrix-preserving platform enables mechanobiologically relevant modeling of stiffness-driven vascular remodeling and indicates YAP and survivin as candidate regulators of maladaptive VSMC mechanotransduction.

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.