Advanced Functional Materials

By decoupling biological function from cellular viability, fixed abiotic cellular materials have emerged as a promising platform for next-generation immunotherapies, preserving essential immunomodulatory activities while enabling unprecedented control over manufacturing, storage, and standardization. Nevertheless, the coupled effects of fabrication history and post-fabrication environmental cues on their biological functionality remain elusive. Here, we show that both preparation route and storage time critically affect the bioactivity of mesenchymal stromal cell (MSC)-derived microtissues. By exploring different devitalization agents, we demonstrate that an ethanol-based strategy provides a green fixation option with comparable preservation of volumetric and fixed cell architecture, as well as immunomodulatory function. Processing protocols did not merely substitute conventional fixation but tailored specific immune-related bioactivity. An unexpected processing protocol and time-dependent enhancement of immunomodulatory performance was observed, with ethanol-fixed microtissues maintaining a stable baseline bioactive profile while increasing functional potency over 8 weeks of storage. We establish a framework for the design of immunomodulatory abiotic cell-derived materials with potential for the treatment of immune-mediated diseases and regenerative therapies, and we hope that the principles uncovered here may contribute to a broader understanding of how devitalized tissues can be engineered, preserved, and functionally tuned, whether lab-made or derived from natural biological systems.

Type II photoinitiators are essential for numerous applications, including advanced 3D printing techniques such as Xolography. Despite offering tunable wavelengths and reaction mechanisms, their limited photoreactivity hinders widespread adoption. Solutions to increase reactivity, particularly in aqueous solutions and in a biocompatible manner, are urgently needed. Here, we report the surprising finding that iodixanol enhances reactivity of type II photoinitiation systems. Supplementing Xolographic print resins with iodixanol increases photoreactivity, which reduces print times and light dosage tenfold, and enables printing of previously unprintable material formulations. Surprisingly, iodixanol supplementation also improves cell viability in a dose-dependent manner, while reducing cell-mediated light scattering. Together, this enables accurate Xolographic printing of highly cell-dense bioresins, which facilitated the biofabrication of engineered living matter with up to 100 M cells mL-1 (>40% cells by volume) with a resolution of ~65 microns. These advances enabled the first demonstration of tissue function in Xolographically-printed materials. Human induced pluripotent stem cell-derived cardiomyocytes were printed into contractile cardiac-like engineered living matter, which exhibited enhanced cell-cell contact and synchronous contractions, confirming tissue level function. As a highly water soluble, cytocompatible, and clinically approved compound, iodixanol therefore represents a valuable and translatable solution to improve the reactivity of type II photoinitiation systems, which enables volumetric biofabrication of highly cell dense living matter. This unlocks a new role for iodixanol in a wide variety of fields including dentistry, chemistry, organic photovoltaics, tissue engineering, and 3D printing.

Recent efforts to reconstruct critical-sized craniomaxillofacial defects using biomaterials have increasingly sought strategies to accelerate proangiogenic processes immediately after surgical implantation to improve host-graft integration. A class of mineralized collagen scaffolds has recently been identified to promote osteogenesis of bone marrow and adipose-derived mesenchymal stem cells both in vivo and in vitro, motivating efforts to identify strategies to promote osteogenic-angiogenic coupling in order to support regenerative healing. Here, we report the first-time use of a glycoengineering approach to generate a population of engineered ASCs (eASCs) from human adipose-derived stem cells (hASCs). This effort inserts an azido sugar onto the cell membrane that can be selectively targeted using DBCO-tagged biomolecules to selectively boost eASCs activity. We report the effects of azido sugar labeling conditions (concentration and incubation time) on eASCs labeling efficiency. We show proliferation and pro-regenerative gene expression activity of eASCs in mineralized collagen scaffolds are largely similar to conventional hASCs. And we demonstrate that molecular cargo functionalized with dibenzocyclooctyne (DBCO) can be conjugated to azido groups on eASCs via click chemistry. Together, this work shows metabolically labeled eASCs have the potential to be used for selective delivery of activity-inducing bioactive cues to enhance regenerative potential.

Carbon is a versatile electrode material that is used in applications ranging from electrical energy storage and electrosynthesis to CO2 conversion, H2 production, and biosensing. The development of pyrolytic carbon electrodes derived from lithographically patterned photoresist structures has expanded the possibilities for creating diverse 2D and 3D electrode designs. In this paper, we present disc-shaped SU-8-derived pyrolytic carbon scaffold electrodes with an open hexagonal honeycomb lattice. The scaffolds were fabricated, using embedded 3D printing within a shear-thinning support bath composed of fused silica nanoparticles (7% w/v) in mineral oil. The rheological properties of the support bath were optimized to enable the printing of low-viscosity materials like SU-8, which would otherwise lack structural integrity in standard extrusion-based 3D printing. The SU-8 scaffolds were then pyrolyzed and characterized using SEM, Raman spectroscopy, Energy Dispersive X-ray, X-ray Photoelectron Spectrometry, and Transmission Electron Microscopy, which revealed graphene-like 'microflowers' on its surface. Electrochemical analysis demonstrated excellent electrochemical properties. The functionality of the scaffold electrodes was validated by differentiation of human neural stem cells into dopaminergic neurons on the scaffold surface, followed by real-time detection of dopamine exocytosis upon cell depolarization.

Developing biomaterials that faithfully recapitulate the complex architecture of native tissues is central to tissue engineering. Conventional hydrogels typically exhibit nanoscale porosity, which limits mass transport and cell migration and thereby constrains tissue development. Here, we exploit liquid-liquid phase separation (LLPS) to generate interconnected macroporous gelatin methacryloyl (GelMA) scaffolds with tunable pore sizes ranging from 2 to 50 m under physiological pH conditions. By mapping the GelMA/dextran phase diagram, we identify a composition range in which LLPS occurs through spinodal decomposition, resulting in a spontaneous bicontinuous, trabecular-like architecture. Pore size can be further tuned by varying polymer concentrations and temperature. We advantageously combined thermal gradients and photopatterning to enable spatial control over pore morphology to fabricate hierarchically structured materials. The biological relevance of these architectures is assessed using fibroblasts cultured within controlled porosity gradients. We show that pore size strongly influences cell infiltration, growth, and spatial organization, with larger pores providing sufficient space for cell migration while reducing the dependence on matrix degradation. Pore size of 7-15 m is identified for maximizing fibroblast growth. Overall, our approach provides a versatile platform for porosity screening, enabling the engineering of biomimetic hydrogels with optimized microarchitectures tailored to specific biological contexts for three-dimensional cell culture.

Therapeutic strategies based on increasing uncoupled respiration (browning) in white adipose tissue (WAT) have great potential for treating obesity-related disorders such as diabetes and steatotic liver disease, but have not had a clinical impact because safe and efficient methods for browning WAT have not been developed. Lipid nanoparticles (LNPs) offer a promising platform for adipose-directed siRNA delivery; however, conventional formulations often exhibit limited activity in adipocytes and can induce inflammatory responses that may restrict repeated administration. Here we demonstrate that LNPs that contain ionizable lipids with three lipid tails and siRNAs targeting TLE3 and ZFP423 can efficiently transfect mature adipocytes and induce browning of WAT in vitro and in vivo while providing the biocompatibility needed for repeated subcutaneous injections. Repeated local administration of BLNPs in diet-induced obese mice resulted in sustained target gene silencing, increased expression of thermogenic markers, altered energy metabolism, and decreased hepatic lipid accumulation despite minimal effects on body weight relative to scramble siRNA controls. Collectively, these findings establish BLNPs as a promising platform for adipose-directed RNA delivery and targeted modulation of thermogenic pathways, providing a strategy for investigating how localized adipose tissue remodeling influences metabolic physiology.

Bone formation and remodeling depend on dynamic biochemical and biomechanical signaling from the collagen-rich osteoid that precedes mineralization, yet the role of osteoid nonlinear mechanics in regulating osteocyte-like network formation remains poorly understood. Here, we engineered a synthetic bottlebrush polymer hydrogel (BB) that mimics key mechanical features of osteoid and compared it to collagen type-I (Col1) matrices with matched shear modulus (~70 Pa) and strain-stiffening behavior. Human bone marrow-derived mesenchymal stem/stromal cells (hMSCs) were cultured for 28 days in growth (GM) or osteogenic media (OM) to examine network formation, and functional connectivity using live cell fluorescence recovery after photobleaching. hMSCs cultured in BB networks and OM showed upregulation of early osteocyte markers compared to Col1. We find that strain-stiffening materials with minimal stress relaxation promote osteocyte-like cell differentiation with functional connectivity, establishing osteoid-mimetic BB hydrogels as a promising matrix to study human osteocytogenesis and osteocyte mechanotransduction in vitro.

Circulating microRNAs (miRNAs) have emerged as promising liquid biopsy markers; however, their clinical translation is restricted by low abundance, biological heterogeneity, and the complexity of multiplex profiling. Herein, we develop a targeted cycling-mediated duplex-specific nuclease (DSN)-nanozyme signal amplification platform (TC-DSN-Nano) that establishes a compartmentalized catalytic transduction strategy for multiplexed miRNA analysis. By encapsulating gold nanozymes within liposomal nanoreactors, this platform spatially separates molecular recognition from catalytic signal generation, preserving nanozyme activity during sensor construction. Upon target miRNA recognition, DSN-mediated recycling induces regenerative release of nanozyme-loaded liposomes from magnetic substrates, converting individual miRNA molecules into amplified catalytic outputs without conventional nucleic acid amplification. The platform enables programmable profiling of six prostate cancer (PCa) associated miRNAs in serum samples. Furthermore, machine learning-assisted integration of multiplexed miRNA signatures enables accurate discrimination among healthy donors, nonmetastatic PCa patients, and metastatic PCa patients, achieving an overall classification accuracy of 90.5%. This work establishes a general compartmentalized nanozyme transduction framework that integrates molecular recycling, catalytic amplification, and computational analysis for liquid biopsy-based cancer stratification.

Digital micromirror device (DMD)-based bioprinting enables high-resolution fabrication of hydrogel-based tissue constructs, but print fidelity and hydrogel mechanics are typically coupled through polymer concentration, light exposure, and crosslinking density. This creates a materials constraint for vascular bioprinting, where constructs must preserve microscale architecture during fabrication while supporting multicellular remodeling, lumen formation, and long-term tissue organization. To meet these requirements, we developed a 4D GelMA-Cad/gelatin hydrogel with time-dependent mechanics that maintains print fidelity while providing a soft, cell-permissive matrix. GelMA-Cad provides a covalently photocrosslinked, bioactive network containing an N-cadherin-mimetic peptide, while uncrosslinked gelatin serves as a transient matrix-modifying component that diffuses from the hydrogel after fabrication, producing further softening without bulk degradation of the GelMA-Cad network. We characterized hydrogel chemistry with NMR, quantified time-dependent changes in stiffness, visualized pore morphology with cryo-SEM, and evaluated the platform in retinal and pulmonary constructs. The 4D hydrogel supports 3D-patterned accuracy, cell viability, inner blood-retinal barrier vasculature, and vascularized lung-alveolar tissue models. Single-cell RNA-sequencing of the pulmonary vascular-alveolar model demonstrated compartment-specific transcriptional responses, including enrichment of lung capillary-associated endothelial features and AT1-like epithelial states. Overall, this platform decouples DMD print fidelity from post-print matrix mechanics for vascularized soft tissue bioprinting and tissue modeling.

Continuous biomarker monitoring with affinity biosensors remains limited by probe saturation, slow dissociation, signal carryover, and regeneration methods that require chemical washing, harsh buffers, or external reset modules. Here, we report a flow-programmed, self-regenerative electrochemical aptamer-based biosensor for continuous 17{beta}-estradiol monitoring. The platform restores the sensing interface by tuning buffer flow through the device, enabling repeated sensing-regeneration cycles without chemical stripping or active-reset hardware. The biosensor achieves a 1.46 pM limit of detection, and a log-linear dynamic range from 100 pM to 1 M in real human sweat, covering physiologically relevant estradiol concentrations. It exhibits high selectivity, with responses to potential molecularly similar interferents remaining below 10% of the 17{beta}-estradiol signal. Under dynamic flow operation, the device shows reversible signal recovery and stable electrochemical performance, with higher buffer-wash flow reducing baseline carryover between measurements. A coupled binding-transport simulation captures the flow-dependent regeneration trends and maps how wash-flow rate, wash duration, and apparent aptamer affinity affect regeneration efficiency. Ex vivo testing in real human sweat, including samples from pregnant women, supports translational relevance. This work establishes buffer-flow programming as a reagent-free route to regenerable electrochemical aptamer sensing for automated, wearable-compatible estradiol monitoring.

Granular hydrogels, made of jammed soft microparticles, are of great interest for 3D (bio)printing, as they combine ideal rheological properties and extensive modularity, yielding favorable microstructures for tissue engineering. Typically, the yield-stress properties of these materials, which facilitate printability, are defined by the preparation state and the initial particle content of the hydrogel. Here, we propose a granular hydrogel whose yield-stress and, consequently, printability and printed scaffolds shape retention can be controlled not only by the initial weight fraction of particles but also by their stimuli-responsive swelling. The responsive microgels are prepared from poly(N-isopropylacrylamide) crosslinked by dynamic covalent disulfide bonds. The particles swelling is triggered by reduction-induced cleavage of the disulfide bonds into two pendant thiol groups, enabling printing of multilayer scaffolds with high shape fidelity. Without chemically induced swelling, the same formulation requires higher particle concentrations to be printable. Importantly, the printed structures can be annealed by oxidizing the thiol units back into disulfide inter-particle bonds. The printed scaffolds are compatible with human dermal fibroblasts (HDF) and support cell-material interactions. This system offers a unique opportunity for on-demand modulation of both printability and scaffold microstructure, enabling unique control over local stiffness, packing density, and porosity in granular scaffolds.

Adoptive cellular therapies can be effective against solid tumors but rely on the identification and expansion of rare tumor-reactive T cells (TRTs). Here, we utilize antigen-presenting cell-mimetic scaffolds (APC-ms), a modular biomaterial platform that presents defined peptide-HLA and co-stimulatory ligands on a fluid lipid bilayer to selectively recover rare antigen-specific T cells from peripheral blood. Independent variation of peptide-HLA, co-stimulatory ligands, and cytokine support defined a formulation that enriched MART-1-specific T cells to above 2% of CD8+ T cells in 35 of 50 HLA-A*02:01+ healthy donors from low or undetectable baseline frequencies. Compared with mo-DCs, APC-ms achieved greater fold expansion of MART-1-specific T cells with increased functional avidity and preservation of an early differentiation phenotype, and generated a higher number of MART-1-specific clonotypes. In five of eight patients with treatment-naive melanoma, APC-ms could enrich MART-1-specific T cells to a median of 13.7% of CD8+ cells (range 0.30 - 57.2%) Moreover, APC-ms could expand T cells specific for an HLA-A*24:01-restricted personal neoantigen that were previously undetectable in peripheral blood of a patient with melanoma. These findings establish APC-ms as a tunable platform for the recovery of rare TRTs from peripheral blood, supporting its further development for therapeutic TCR discovery and personalized adoptive cell therapy.

Gas-bubble-enhanced focused ultrasound (FUSGB) is advancing clinically across a myriad of applications, including targeted drug delivery through transient blood-brain barrier opening (BBBO). Its broader translation requires a better understanding of the bioeffects that enable reproducible enhancement of barrier permeability while avoiding vascular injury, underscoring the need to clarify the relationship between acoustic exposure, bubble activity, and the biological response central to treatment optimization. These interactions are difficult to isolate in vivo, and acoustic reflections, geometry, and field distortion in conventional cultureware hinder quantitative in vitro studies. Herein, we present a theoretically and experimentally characterized ultrasound-transparent organ-on-chip device with >99.9% US transparency that enables quantitative in vitro modeling of the FUSGB procedure and study of BBBO. Furthermore, submicron bubbles (sMB, ~800nm) were fabricated and characterized. Acoustic dose-dependent subharmonic and broadband cavitation dose curves (SCD and BCD), as well as temporal responses, were studied. A 3-day accelerated Caco--2 surrogate barrier with a high TEER (~1200xcm2) was used to demonstrate US dose-dependent targeted barrier opening, visualized using an in vitro Evans Blue assay. Together, this study and its findings establish a foundation for quantitative in vitro modeling of FUS BBBO, as well as other US interactions in microphysiological systems, supporting systematic evaluation of procedural regimens, large-parameter-space optimization, acoustic safety window, and exposure conditions for brain drug delivery, and additionally enabling mechanistic insight into FUSGB BBBO.

Glial cells play essential roles in maintaining neural tissue homeostasis and limiting the spread of injury-induced neuroinflammation, yet their dysfunction can also exacerbate neurodegenerative, neuroimmune, and neurodevelopmental disorders. Therapeutic targeting of specific glial cell populations would open up new treatment possibilities, but currently available viral and non-viral delivery vehicles are limited by carrier toxicity as well as poor delivery efficiency and specificity. To work towards new glia-targeted, non-viral delivery vehicles, we performed an in silico analysis on neural cell specific RNA-Seq datasets in mice to identify surface molecules differentially enriched on neurons, astrocytes, and microglia. We identified Slc2a5 (Glut5) as a microglia-enriched transporter and validated its microglia specific expression in healthy murine neural tissue using RNA in situ hybridization. By employing a sequential thiol-ene and enzymatic catalyzed reaction scheme, we synthesized polyelectrolytic dendrimers with multivalent presentation of fructose, the natural ligand for Glut5, and formulated nano-sized polyionic complexes (PICs) loaded with protein or nucleic acid cargo by mixing oppositely charged dendrimers. Fructose functionalized PICs lacking cationic surface charge enabled fructose-dependent intracellular protein delivery to Glut5-expressing human breast cancer cells (MCF-7) and mouse fibroblasts, while restricting uptake by Glut5-negative mouse astrocytes, confirming transporter-dependent selectivity in vitro. Fructose functionalized PICs resulted in minimal neuroinflammation when injected into mouse striatum at 1 mg/ml but elicited concentration-dependent neural tissue toxicity at higher doses. Fructose-PICs failed to achieve microglia specific intracellular delivery of functional proteins when injected into healthy neural tissue but aided in directing protein delivery to microglia and astrocytes at ischemic stroke lesions. Together, our findings demonstrate proof-of-principle for using in silico RNA-seq screening workflows to identify cell specific surfaceome targets and incorporating that insight into a modular biomaterial platform for targeted drug delivery.

Engineered human neuromuscular models are limited by a trade-off between biological fidelity and architectural control: self-assembled organoids organize stochastically, while engineered 3D tissues impose anisotropy through passive tension at the edges without internal guidance. Here we encode architectural guidance into human neuromuscular tissues by coupling a three-dimensional, cell-laden biomatrix to a xolographically printed hydrogel substrate featuring sub-millimeter surface topography. We demonstrate that grooved substrates increase human primary myotube alignment and maturation in the overlying 3D tissue, while guiding directional axon extension from human iPSC-derived motor neuron spheroids. We show that combining both cell types along a shared alignment axis establishes functional neuromuscular connectivity, evidenced by acetylcholine receptor clustering, glutamate-evoked contraction and its blockade by d-tubocurarine (curare), and yields innervation coverage of centimeter scale tissues. Overall, this platform combines compliant substrates, mesoscale tissue architectural guidance, and human-relevant cell biology in a single untethered construct for studies of neuromuscular tissue development and function.

Regulatory T cells (Tregs) are key mediators of immune resolution and tissue repair following acute kidney injury (AKI), yet strategies to selectively enrich Tregs within the renal microenvironment remain limited. Interleukin-2 (IL-2) is essential for Treg survival and function, but systemic IL-2 delivery is constrained by a short half-life, narrow therapeutic window, and risk of off-target activation of cytotoxic T cells. Effective Treg-based immunomodulation may therefore require both localized cytokine signaling and targeted recruitment of precursor immune populations. Here, we present a sequential, biomaterial-based immunomodulatory strategy that integrates immune cell recruitment with sustained cytokine delivery. An injectable granular hydrogel physically encapsulating the chemokine CCL21 was used to initially recruit CD4+ T cells to the injured kidney. Subsequently, supramolecular guest-host interactions were leveraged to deliver IL-2 modified with the hydrophobic "guest" moiety adamantane, enabling prolonged local cytokine release over 28 days. In healthy mice, we observed early CD4+ T cell recruitment, followed by a pronounced increase in Treg frequency, consistent with immune reprogramming driven by our sequential delivery system. In a murine model of bilateral ischemia-reperfusion (BiAKI), this injectable biomaterial induced a local increase in the proportion of FOXP3-expressing Tregs and a concomitant decrease in the levels of AKI markers. This two-step immunomodulatory approach minimizes acute immune activation while promoting long-term enrichment of Tregs within the renal microenvironment. Together, these findings demonstrate that granular hydrogels with supramolecular host capability can orchestrate immune recruitment and differentiation in a spatiotemporally controlled manner, providing a versatile immunomodulatory platform for applicability in kidney disease.

Protein nanofibers are hold great promise as genetically programmable scaffolds for constructing functional material interfaces. AtaA, a giant trimeric autotransporter adhesin from Acinetobacter sp. Tol 5, forms an elongated architecture from the bacterial cell surface, enabling the cells to adhere directly to a wide variety of abiotic surfaces. However, the potential use of AtaA as a scaffold with additional biological functions remains largely unexplored. In this study, we investigated the use of AtaA as a self-immobilizing scaffold for constructing enzymatically active surfaces via horseradish peroxidase (HRP)-catalyzed tyrosine coupling. We prepared a recombinant AtaA nanofiber fragment (NhNs-AtaA) and its derivative containing two tyrosine-containing loop structures (YL-NhNs-AtaA). Both recombinant proteins retained their adhesive properties. Treatment with HRP and H2O2 generated high-molecular-weight products from both proteins, and dityrosine fluorescence emission indicated the formation of tyrosine-derived covalent cross-links. Y-Loop insertion further increased the consumption of monomeric AtaA and promoted the formation of high-molecular-weight products. The removal of arginine, which was included during purification, further increased the loss of monomeric AtaA in both constructs, indicating that intermolecular protein association influenced productive AtaA cross-linking. NhNs-AtaA and YL-NhNs-AtaA were combined with Y-tagged bacterial alkaline phosphatase (BAP-Y). HRP-mediated coupling generated high-molecular-weight products consistent with the cross-linked AtaA-BAP-Y conjugates and enabled the retention of BAP activity on AtaA-coated surfaces without prior chemical modification. Although Y-Loop insertion enhanced polymerization in solution, it reduced AtaA adhesion and consequently lowered surface-bound phosphatase activity, revealing a trade-off between cross-linking reactivity and native adhesive function. These findings establish AtaA as a self-immobilizing protein nanofiber scaffold for constructing enzymatically active surfaces, and suggest the potential extension of this strategy to other AtaA-based interfaces.

Microlasers based on whispering-gallery modes (WGMs) provide bright, spectrally narrow emission, making them ideal optical probes for high-resolution cellular tagging, single-cell tracking, and biosensing. To reproducibly apply WGM microlasers in biomedical or tissue-engineering contexts, control over the number of lasers in a cell population is highly desirable. Here we use a commercial instrument for flow cytometry-based cell sorting to obtain HEK293T cell populations with a controlled number of polystyrene laser particles (LPs). By modifying the particle surface with poly(ethyleneimine) (PEI) or lipofectamine, we enhance LP-association to cells. We demonstrate that our sorting procedure yields viable cells showing unchanged proliferation rates. Manufacturer-dependent differences in particle-cell interactions were observed and investigated by scanning and transmission electron microscopy (SEM/TEM) and flow cytometry. Finally, we show that the same sorting approach enables the generation of multi-cellular spheroids with a defined ratio of LP-containing and LP-free cells. This work lays the foundation for larger tissue engineering studies with defined LP populations and control over LP-placement with respect to the cell.

Microfluidics-assisted encapsulation of cells in hydrogel microbeads has found diverse applications in tissue engineering, disease modelling, and drug testing. However, upscaled production of submillimeter-sized microbeads, each encapsulating optimally tens to hundreds of living cells, remains a challenge. Excessive viscous stresses or non-homogeneous crosslinking reactions hamper droplet monodispersity, hydrogel integrity, and/or cell viability. Herein, we present a device consisting of (i) tens of parallel step-emulsifiers arranged radially around the hydrogel inlet and (ii) an in-flow UV crosslinking system capable of continuous generation and crosslinking of up to around 45000 microbeads/min, each encapsulating N~50 cells, at cell viability exceeding 80%. We use gelatin methacryloyl (GelMA) as the biomaterial of choice and establish a unique sweet spot in terms of UV wavelength, irradiance, and exposure time- the latter controlled via the net applied flow rate and the length of the UV-exposed microchannel- at which we achieve an optimal balance between long-term microbead stability and cell viability. In particular, we observe a strong correlation between reduced cell viability and poor crosslinking efficiency, the latter attributed to the presence of a spontaneous core-shell structure. We further study the impact of added methacrylated hyaluronic acid (HAMA) and extracellular matrix (ECM) on cell proliferation and microtissue formation in the case of triple-negative breast cancer (TNBC) cells for future application in drug testing. The upscaled production of the encapsulated microtissues demonstrated here provides new perspectives for both drug testing and cell therapies where the precision in microenvironment formulation as well as production throughput remain of primary importance.

A broad-spectrum antiviral is required to enable rapid intervention against current, newly emerging and mutating viruses. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus (IAV), Sindbis virus (SINV) and chikungunya virus (CHIKV) all engage negatively charged moieties on host cells, such as heparan sulfate (HS) and sialic acid, to facilitate attachment for entry and infection. We designed HS-mimetic nanoparticles in the form of polymer vesicles (polymersomes) by blending membrane-forming and sulfonated copolymers. These biocompatible polymersomes successfully inhibited host cell infection of HS-dependent SARS-CoV-2 and HS-independent IAV in vitro with sub-nanomolar potency. Multivalent interaction of several virus ligands with a single polymersome as quantified by fluorescence correlation spectroscopy likely contributes to their potency. The sulfonated polymersomes also functioned in vivo as demonstrated by a reduction in the spread of SINV, an alphavirus model for CHIKV, in zebrafish embryos, which led to a significantly increased survival. Hence, our polymersomes could form the basis for an urgently required multifunctional broad-spectrum antiviral nanomedicine.