ACS Applied Bio Materials

Pathogenic bacterial extracellular vesicles (BEVs) can disrupt the blood-brain barrier (BBB), leading to neuroinflammation. Prior in vitro studies of this process were performed in simple models that may have lacked important physiological factors. We sought to determine if treatment with Escherichia coli-derived BEVs could directly compromise the integrity of a BBB lab-on-chip model or if an immune component was required. Our device featured isogenic human induced pluripotent stem cell-derived brain microvascular endothelial-like cells (BMECs) and pericytes separated by an ultrathin, porous silicon nitride membrane. BEVs and free lipopolysaccharide (LPS) were capable of causing upregulation of intercellular adhesion molecule-1 on the BMEC surfaces, which is important for immune cell recruitment. However, neither BEVs nor LPS at physiological doses caused pronounced loss of BMEC tight junction proteins, nor did they increase barrier permeability to small dye molecules. In contrast, stimulating THP-1 macrophages with BEVs led to increased production of pro-inflammatory cytokines, and conditioned media from the stimulated macrophages disrupted BMEC tight junctions and increased barrier permeability. Our work demonstrates the importance of incorporating an immune component in studies of BEV-mediated disruption of BBB models.

The rapid response to the Coronavirus Disease (COVID-19) pandemic highlighted mRNA as an attractive modality for vaccines and therapeutics to address infectious diseases, cancer, and other diseases. The current analytical methods for identification and quantification of both the mRNA construct as well as the resulting expressed protein(s) relevant to mRNA vaccines are inherently singleplex and usually labor and time intensive, presenting a bottleneck as these vaccines become increasing multivalent. Here, we first present performance data from an approximately 2-hour DNA microarray assay developed specifically to provide identity and quantity measurements for the mRNA constructs present in an influenza virus hemagglutinin (HA)-encoding multivalent mRNA vaccine regardless of the specific strain or codon optimization strategy utilized. The assay functions on both naked and lipid nanoparticle (LNP)-encapsulated mRNAs without the requirement of an upfront mRNA extraction or amplification. Second, we show that a separate [~]2-hour multiplexed immunoassay executed on the same VaxArray Platform can be utilized to measure the expressed proteins produced from these influenza HA mRNAs post-transfection as an in vitro potency assay readout. Both assays provide the necessary specificity for each component present in a multivalent mixture and represent new tools in the analytical toolbox for multiplexed mRNA vaccine analytics.

Nanotechnology is rapidly transforming medicine by enabling versatile platforms for targeted delivery, controlled release, and intracellular transport of therapeutic payloads. Polymeric mesoscale nanoparticles (MNPs) are 300 to 500 nm in diameter with a PEGylated surface that exhibit unique renal tropism, specifically toward renal tubular epithelial cells. Despite their well-described therapeutic applications and route of localization to the tubules, we do not yet understand their physicochemical stability and cellular internalization mechanisms. In this study, we investigated the stability of MNPs under stress conditions by subjecting them to repeated freeze-thaw cycles and varying storage conditions to evaluate the effects on particle size and polydispersity index. MNPs demonstrated negligible changes in size and PDI up to 4 freeze-thaw cycles. We found that both empty and dye-loaded MNPs demonstrated negligible change in size under standard -20{degrees}C storage conditions. While empty MNPs were only stable at room temperature for one day, and not at 37{degrees}C, dye-loaded nanoparticles were stable for at least eight days under both storage conditions. We then performed in vitro studies to evaluate MNP cellular uptake mechanisms using the human renal cell carcinoma cell line 786-O treated with pharmacological inhibitors of uptake pathways. We found that MNP internalization is almost entirely prevented by dynamin inhibitors, while macropinocytosis inhibition also reduced uptake, suggesting that such standard nanoparticle uptake pathways are robust to the mesoscale size range. These findings provide key insights into the stability profile and endocytosis mechanisms of MNPs, which are critical for materials scale-up and translation of novel kidney-targeted drug and gene therapies.

Efficient, aggregation-free extracellular vesicles (EVs) labeling is essential for studying their dynamics in-vitro and in-vivo. However, traditional dyes introduce limitations including aggregation, membrane intercalation, fluorescence transfer and inconsistent performance across EV sources thus distorting quantification, altering surface properties and confounding uptake and biodistribution analyses. Here, we systematically evaluated CytoLight, a luminal dye traditionally used for live-cell imaging, as an alternative for EV quantification, characterization, uptake analysis and in-vivo tracking, benchmarking it against PKH26, CFSE and ExoBrite across multiple platforms. CytoLight generated stable, intravesicular fluorescence without aggregation or membrane alteration, eliminating artifacts characteristic of conventional dyes. Using fluorescence-NTA and single-EV flow cytometry, CytoLight showed more consistent labeling across EV types than CFSE or ExoBrite, while avoiding PKH-related micelle-driven artifacts and exhibited compatibility with CD81 dual-detection. In uptake assays, CytoLight produced EV-specific endocytosis-dependent internalization signals exceeding labeled-BPS/protein controls. In-vivo, CytoLight-labeled EVs enabled fluorescent biodistribution mapping showing conventional EV tropism patterns distinguishable from labeled-PBS controls. These findings establish CytoLight as an effective, aggregation-free EV-labeling strategy. Its stability, specificity, compatibility with single-EV platforms and reliable performance in both cellular uptake and biodistribution studies position CytoLight as a practical, scalable alternative to current dyes, providing a stronger foundation for standardized and reproducible EV research.

mRNA-lipid nanoparticles (LNP) have proven their potential as a rapidly adaptable vaccine platform and promise to revolutionize numerous therapeutic areas. A major hurdle towards the widespread adoption of mRNA-LNP vaccines and therapeutics is their limited liquid shelf-life compared to more established modalities currently necessitating an ultralow temperature cold-chain to enable their distribution and storage. While ongoing efforts aim to improve liquid stability through chemical modification of mRNA and lipid components, complementary strategies that are broadly applicable across chemistries may further accelerate translation. Here, we present an approach to improve the liquid shelf-life of mRNA-LNPs that does not rely on modifications to the mRNA or LNP chemistry. In particular, we show that bleb formation induced by high ionic strength acidic citrate buffers during LNP formation reduces mRNA degradation and retains in vitro activity during extended liquid storage. We observed an increase in the in vitro activity storage half-life from 2.8 to 18.9 days at 25{degrees}C when prepared using high ionic strength buffers translating into a [~]7-fold improvement in the liquid shelf-life of MC3-LNPs. This enhanced stability of LNPs with large amount of bleb formation was mainly attributed to reduced rates of lipid-mRNA adduct formation and mRNA fragmentation. Furthermore, the acidic buffer dependent stabilization was observed across different ionizable lipids with the extent dependent on the ionizable lipid head group. We envision that the induction of bleb formation via selection of appropriate acidic mixing buffers may represent a universal approach to enhance mRNA-LNPs stability and enable extended long-term refrigerated storage.

High-sensitivity flow cytometry (FC) allows multiparametric analysis of nanoparticles (NPs) and extracellular vesicles (EVs). With new instruments available, studies that evaluate their performance using the same materials in a controlled environment are required. Here, we performed a comparative study to investigate the capabilities of three flow cytometers, namely the NanoFCM (NF), BD Influx (IF) and CytoFLEX LX (CF). Firstly, we analyzed a mixed population of silica NPs (SiNPs, 68, 91, 114 and 155 nm) by using light-scatter based detection thresholds (SSC, FSC, VSSC) across a concentration range from 106 to 109 particles/mL. Next, we analyzed fluorescent recombinant EVs (rEVs) by comparing light-scatter based thresholding (488 nm SSC available for all platforms), the combination of SSC thresholding with a fluorescent gate, and fluorescent thresholding for their qualitative and quantitative analysis. We here provide the strengths and limitations for each platform regarding the analysis of differently sized NPs at different sample concentrations.

Developing wound dressings that support healing and allow real-time monitoring is a key priority in modern wound care. In this study, we designed a curcumin-loaded carboxymethyl cellulose (CMC)/polyvinyl alcohol (PVA) composite dressing with integrated pH-responsive colorimetric sensing. The films were made by solution blending and freeze-drying. They formed porous, absorbent structures that quickly absorbed fluid and managed wound exudates effectively. Curcumin served as both a therapeutic agent--delivering antioxidant, anti-inflammatory, and antibacterial effects--and a natural colorimetric indicator through its keto-enol tautomerism, enabling reversible pH-dependent transitions visible to the naked eye. UV-Vis spectroscopy confirmed absorbance shifts under acidic and alkaline conditions. It also showed that curcumin remained [~]80% stable after 14 days in the polymer matrix FTIR and SEM confirmed successful incorporation and uniform distribution of curcumin within the polymer network. Cytotoxicity assays demonstrated excellent biocompatibility, while disc diffusion and MIC assays revealed significant antibacterial activity of the curcumin-loaded films against Pseudomonas aeruginosa, confirming their potential to reduce bacterial growth. Smartphone-based RGB analysis showed a strong correlation with pH (R2 {approx} 0.99), highlighting the feasibility of low-cost digital wound monitoring. Mechanical testing indicated sufficient tensile strength and flexibility for practical wound application. Quantitative antibacterial data (inhibition zone diameter and MIC) supported strong antimicrobial performance. The primary objective of this study was to develop a multifunctional wound dressing capable of both protecting and monitoring wounds in real-time. The proposed system is specifically designed for chronic and infected wounds where pH imbalance delays healing. In addition to antimicrobial activity, the fabricated films demonstrated desirable swelling capacity and sustained curcumin release, further highlighting the practical applicability of the dressing in wound care. Cost- benefit analysis demonstrated clear economic advantages over commercial gauze-based and hydrocolloid dressings. The fabrication method is compatible with industrial scale-up, although process optimization is required. Overall, the curcumin-loaded CMC/PVA dressing provides a multifunctional platform that combines biocompatibility, antibacterial activity, pH-responsive biosensing, and cost-effectiveness for next-generation wound care. Future studies will investigate in vivo performance, long-term stability, and clinical translation potential to validate its effectiveness in real-world conditions. Overall, the curcumin-loaded CMC/PVA dressing provides a multifunctional platform that combines biocompatibility, antibacterial activity, pH-responsive biosensing, mechanical stability, and cost-effectiveness for next-generation wound care. Future studies will investigate in vivo performance, long-term stability, and clinical translation potential.

Polymeric 3D printing of microfluidic devices for biosensing is an appealing fabrication alternative for rapid manufacturing of biosensing devices with complex geometry in a streamlined, repeatable and cost-effective manner without the need for expensive instrumentation such as those employed in photochemical etching and soft lithography. Hybrid 3D printed paper-based microfluidics is an emerging area which harnesses the unique properties of both, merging the construction of microfluidic structures and the inherent capillary-driven flow within paper substrates. In this work, we have fabricated hydrophobic barriers by 3D printing a single layer of machinable wax, thermoplastic polyurethane, polylactic acid and polypropylene directly on chromatography paper to create open microchannels and determine the most suitable material. Characterization of each open microchannel using the four materials revealed polypropylene as the most reliable material with high hydrophobic barrier integrity and resolution. Polypropylene achieved functional microchannels with a resolution of 621 {+/-} 33{micro}m, hydrophobic barrier integrity of (93.75 {+/-} 9.16%), wicking speed of 0.38mm/s and optimal hydrophilicity of channels (51.4 {+/-} 8.36 {degrees}) with minimal embedding during thermal curing. To demonstrate proof of principle, a fluorescence assay demonstrating the formation of a dimeric g-quadruplex structure from a g-rich sequence which significantly enhances fluorescence of thioflavin T was implemented.

Thrombogenicity causes significant complications in the application of blood-contacting implants, requiring strategies to prevent adverse coagulation reactions. The thrombotic responses to the foreign surfaces are mainly driven by surficial factors such as surface energy, topography, and electrochemical interactions. Although anticoagulation therapies reduce the risks of clotting, patients might still encounter bleeding complications. Therefore, rather than high-risk anticoagulation therapies to counteract coagulation, it is essential to ensure hemocompatibility through the materials intrinsic properties. Endothelialization is crucial in preventing thrombotic complications, with various strategies explored for facilitating endothelial cell adhesion and proliferation. We investigated the impact of crystallographic anisotropy on endothelial and blood cell interactions on four main planes (A-, C-, M-, and R-planes) of single crystalline alumina (-Al2O3, sapphire). Employing advanced surface characterization techniques, including SIMS, KPFM and Zeta potential measurements, our study sheds light on the hemocompatibility of biomaterials considering anisotropic effects. We elucidated that the A-plane of alumina promotes endothelialization and suppresses platelet activation in contrast to other crystallographic planes. Our investigation into cell-surface interactions provides valuable insights and contributes to the advanced biomaterial design, ultimately leading to enhanced clinical outcomes.

Silica-encapsulated gold nanostars (AuNStar-SiO2) are a widely used plasmonic nanoparticle platform for surface-enhanced resonance Raman scattering (SERRS) bio-applications. In this paper, we demonstrate that coupled nanostar subpopulations can dominate the ensemble-average SERRS response of the suspension and that near-neutral standard cell culture conditions are sufficient to hydrolyze the silica nanoshell and introduce variability in signal intensity following in vitro endocytosis. Monomeric and oligomeric AuNStar-SiO2 fractions were isolated using continuous density-gradient centrifugation and monomeric populations were found to exhibit significantly weaker SERRS compared to their oligomeric counterparts. Using monomer-enriched AuNStar-SiO2, we investigated the stability of the silica nanoshell under conditions representative of sequential acidification during endocytosis and characterized the subsequent changes to nanoparticle optical properties. In acidic environments, reflecting lysosomal pH, the silica shell was stable, whereas near-neutral and alkaline conditions in cell culture medium induced silica-shell hydrolysis, nanostar release, and interparticle aggregation, leading to transient SERS amplification. When cells were treated with AuNStar-SiO2 under near-neutral and acidic conditions, we observed the opposite trend in SERS signal strength. At pH 7.4, the SERRS signal was suppressed even though transmission electron microscopy (TEM) images of intracellular nanoparticles showed progressive extents of silica hydrolysis, while at pH 6.4 SERS signal was strong and the silica shell of intracellular nanoparticles remained intact. Together, these findings show how SERRS output can differ between control conditions and biological applications, highlighting the role that local environmental factors play in nanoparticle stability and performance. Our results highlight the previously overlooked role of silica nanoshell instability on SERRS signal output in physiological environments and describe opportunities to harness silica nanoshell hydrolysis to improve the biomedical application of silica-coated plasmonic probes.

In vitro models are increasingly critical for interrogating cancer biology and therapeutic response, however, accurately recapitulating the tumor microenvironment (TME) remains a persistent challenge, particularly in head and neck cancers (HNC) characterized by complex cell-matrix interactions and heterogeneity. Current models often lack independent tunability of biochemical and biophysical cues, limiting systematic investigation of microenvironmental cues in a high-throughput format. Here, we establish a 3D droplet-based bioprinting platform for the fabrication of customizable in vitro TME models using poly(ethylene glycol) (PEG) hydrogels. Human HNC cell lines (FaDu and 2A3) with differing HPV statuses were bioprinted into PEG matrices spanning physiologically relevant stiffnesses (0.7-4.8 kPa) and compositions, including non-functionalized PEG and peptide-functionalized PEG (PEGfnc: RGD, YIGSR, CNYYSNS) and cultured for 7 days. Cluster growth, cell viability, and cluster morphology were assessed across multiple time points, matrix compositions, and matrix stiffnesses. Proliferation and endpoint phenotype expression were visualized using confocal microscopy through immunofluorescence. Results indicated enhanced cell viability in PEGfnc matrices, compared to non-functionalized matrices, while effect of matrix stiffness was less prominent. Median cluster size reached 40-50 m by day 7, and linear mixed-effects modeling identified how changes in cluster surface area, volume, and tumoroid complexity varied with cell type, matrix, and stiffness. By decoupling and systematically varying key TME parameters, this approach provides a robust and scalable framework for dissecting tumor-matrix interactions and advancing physiologically relevant in vitro models for cancer research and therapeutic screening.

Nanoplastics generated from plastic waste in our ecosystems are becoming increasingly prevalent as bulk plastics exposed to natural factors like water and sunlight fragment to the nanoscale over time. These incidental nanoplastics span a wide range of physicochemical properties, which makes studying nanoplastic interactions in biological systems difficult. Here, we characterized the behavior of incidental nanoplastics generated through mechanical abrasion within coacervate droplets to probe the surface properties of the nanoplastics. We used elastin-like polypeptides (ELPs) to create hydrophobic or charged coacervate microenvironments. Using optical microscopy and fluorescence quantification, we observed that nanoplastics made from polyethylene terephthalate (nPET), nylon 6 (nPA), and polystyrene (nPS) exhibited distinct partitioning behavior with more favorable interactions with hydrophobic droplets. This indicated that the hydrophobic polymer backbone was the predominate surface feature despite exposed functional groups of the incidental nanoplastics, in contrast to findings with model carboxylated latex nanospheres (nPS-COOH). Furthermore, the selective partitioning of incidental nanoplastics into the hydrophobic droplets was able to capture over 80% of nPET in solution, and after recovery of the protein droplet, was able to cumulatively capture over 75% of the nPET feedstock across multiple cycles. This work explores the nuanced surface characteristics of incidental nanoplastics, expands the application of coacervates as chemical probes, and demonstrates a biopolymer approach for effective nanoplastic removal.

Detection of micro- and nanoplastics (MNPs) in human tissues has raised growing concern about their biological effects on tissue and cell function. While previous studies have examined MNP-cell interaction, most focused on limited cell and plastic types. Here, we present a comprehensive, quantitative investigation into how different types of nanoplastics (NPs) associate with and affect diverse cell types under physiologically relevant conditions. Using microfluidic-calibrated fluorescence microscopy, we quantify NP accumulation in cells in vitro and match cellular NP concentrations to levels reported in human tissues. While cell-associated NPs could be gradually released in vitro, they persist in vivo for over one month without detectable reduction in a mouse model. We discover that NP exposure at these levels broadly impairs cell proliferation across epithelial, endothelial, fibroblast, and immune cells, with cell type-dependent sensitivity. NP exposure also reduces motility in T cells and fibroblasts, with more complex effects observed in macrophages. Mechanistically, NP-cell association and trans-epithelial transport involved not only classical endocytic regulators but also pathways related to ion and water transport. Notably, NP association and release were highly sensitive to the extracellular fluid environment within the physiological range. By testing inhibitors of these pathways, we identified molecules that reduce NP-cell association and promote release. We further compared common NPs found in human samples and widely used in research: polystyrene (PS), polyethylene (PE), and polypropylene (PP). Although these NPs similarly impaired proliferation and motility, they showed markedly different cellular association and release dynamics. These findings reveal the impact of NPs on tissue cell functions and uncover novel regulatory pathways, establishing a quantitative framework for studying NP-cell interactions in biologically relevant conditions.

To achieve a therapeutic effect, nanoparticles delivering nucleic acids must facilitate endosomal escape (EE) of their cargo. Despite extensive research, the mechanisms that lead to an effective EE are not sufficiently understood. Herein, we utilized Molecular Dynamics (MD) simulations in All Atom (AA) and Coarse Grained (CG) resolutions to differentiate the interaction of four polymeric formulations (polyplexes) and one lipid nanoparticle (LNP) with endosomal membranes. On the one hand, the results emphasize the benefit of hydrophobic residues in the nanoparticles. On the other hand, the role of anionic lipids in the biological membranes is demonstrated. Furthermore, the identified interaction patterns were successfully correlated to the in vitro performance of the formulations. For the first time, different EE mechanisms of polyplex formulations are visualized in simulation and therefore distinguishable from one another. Hence, this work highlights the power of MD simulations for taking a big step towards better understanding EE efficiency. TOC O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=107 SRC="FIGDIR/small/711661v1_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@abba74org.highwire.dtl.DTLVardef@5e2b8eorg.highwire.dtl.DTLVardef@7db144org.highwire.dtl.DTLVardef@1034e_HPS_FORMAT_FIGEXP M_FIG C_FIG

Cell-penetrating peptides (CPPs) can deliver biomacromolecular cargos into cells, potentially enabling a new mode of intracellular drug delivery. However, a major problem with CPP-mediated delivery is entrapment of CPPs within endosomes and covalent linkages ensure CPPs and cargos share a common fate. We previously developed a CPP-adaptor system based on reversible, calcium-dependent cargo binding that produces cargo release from adaptors as complexes dissociate following internalization and Ca2+ efflux from early endosomes. Having employed CPP-adaptors with an array of protein cargos of differing charges, it became apparent that positively charged cargos often appeared to dominate internalization and that association with the adaptor had little effect. To systematically address the effects of cargo charge and CPP function, we tested the ability of several adaptors to increase internalization of a set of adaptor binding GFP cargos having net charges of +9, +15, +20, +25 and +36. Intrinsic internalization of these cargos reproduced reported patterns showing that positive charge increases internalization. However, labeling these cargos with a chemical fluorophore revealed that GFP fluorescence grossly underestimated total internalization. Internalization was charge and concentration dependent with more positive cargos showing apparent saturation of internalization at 100-400 nM, well below the concentrations at which covalently linked CPP-cargos are dosed. We tested the ability of 5 adaptors to internalize these cargos. Our prototype adaptor, TAT-CaM, was completely ineffective with the +9 cargo, but internalized moderately charged cargos extremely efficiently at concentrations far below the {micro}M range. A derivative adaptor, TAT-LAH4-CaM, was highly effective with all cargos and produced similar maximal internalization at 100-400 nM. However, two adaptors specifically designed with increased positive charge inhibited internalization of the most positive cargos. One of these, GFP-CaM, based on the supercharged GFP with net charge of +36, did increase internalization of the least positive cargos, demonstrating an adaptor with high affinity for the cell surface can increase internalization of a neutral cargo at very low concentration. The common maximal level of intrinsic GFP cargo internalization correlated with surface loading of these cargos, suggesting a limit to the beneficial effects of increased plasma membrane association. However, TAT-CaM further increased internalization via an apparently distinct mechanism. In this limited study of the interaction of cargo charge and adaptor efficacy, we found diverse behaviors that hint at the power and flexibility possible with adaptor/cargo internalization.

Flexible and textile-integrated electrochemical systems offer a convenient, user-friendly and non-invasive platform for continuous biochemical monitoring. In this study, a fully flexible and low-profile electrochemical system was developed by fabricating both the glucose biosensor and a compact potentiostat implemented on a polyimide (PI) filament circuit. The glucose biosensor was realized via direct laser writing (DLW), enabling precise electrode patterning and seamless integration with the potentiostat filament circuit. The integrated system exhibited a linear chronoamperometric response to glucose concentrations ranging from 0 to 0.25 mM in artificial sweat (AS). Further evaluation on cotton textiles soaked in AS and under mechanical bending confirmed stable performance, flexibility, and robustness. These findings highlight the potential of the PI-based potentiostat-sensor system for wearable, textile-integrated glucose monitoring and broader healthcare applications.

Biocompatible fluorosurfactants are essential for many droplet microfluidic workflows but are often obtained from commercial sources because published syntheses of perfluoropolyether (PFPE)-based surfactants typically require acid chloride intermediates and chemistry-oriented purification methods. These requirements can limit access for biology and clinical laboratories seeking low-cost or customizable surfactant systems. Here we describe a practical method for preparing functional PFPE-based fluorosurfactant materials by direct carbodiimide coupling of functionalized PFPE carboxylic acids(Krytox 157 FSH) to amine-containing head groups under laboratory-accessible conditions. Using this approach, we prepared a PFPE-polyethylene-glycol (PFPE-PEG) material from Jeffamine ED900 and a PFPE-Tris material from Tris base. Because these products were not fully structurally characterized, we present them as functional reaction products and evaluate them by use in biomicrofluidic workflows rather than by definitive compositional assignment. PFPE-Tris was useful for generating relatively uniform small droplets, whereas the PFPE-PEG preparation supported a broader range of biological applications. These materials were used in genomic library screening for {beta}-glucosidase activity, thermocycling-associated droplet workflows, and protein crystallization experiments. In addition, the PFPE-PEG preparation improved emulsion behavior in many protein crystallization screens that were unstable with a commercial droplet oil used in our laboratory. This method reduces the practical barrier to in-house fluorosurfactant preparation and allows biology-focused laboratories to explore head-group chemistry, oil composition, and operating conditions without complete reliance on commercial reagents. The results support this workflow as a useful entry point for biomicrofluidics laboratories, while also highlighting the need for careful interpretation of thermocycled droplet assays and for future analytical characterization of the resulting materials. Significance statementDroplet microfluidics relies on fluorosurfactants that are often costly and difficult to synthesize outside of chemistry-focused settings. We describe a simple, biology-laboratory-compatible approach for generating functional perfluoropolyether-based fluorosurfactant materials using direct carbodiimide coupling and straightforward cleanup. The resulting materials supported multiple biomicrofluidic workflows in our laboratory, including enzymatic screening and protein crystallization, and provide a practical route for groups seeking lower-cost and more customizable surfactant systems.

A programmable 4-input cascade DNA logic gate utilizing toehold mediated strand displacement (TMSD) was implemented on a 3D printed hybrid paper-polymer vertical flow device (3D HPVF) for on/off sensitive and specific fluorescence detection of platelet derived growth factor BB (PDGF BB). Polypropylene was 3D printed directly on paper and thermally cured to create micro paper analytical devices ({micro}PADs). The 3D HPVF comprised of three layers of {micro}PADs enclosed in a casing that clamped each {micro}PAD securely to ensure seamless and efficient wicking between layers. In the presence of PDGF BB, a partially complementary strand to a PDGF B aptamer (PDGF B Apt), cApt, was liberated from a PDGF B Apt/cApt duplex in solution. The solution was then deposited on the 3D HPVF with a dimeric g-quadruplex hairpin. The 4-nucleotide toehold region on the cApt started the hybridization reaction with the dimeric g-quadruplex hairpin (dGH) opening it up allowing formation of a dimeric g-quadruplex structure that binds with thioflavin T (ThT) with enhanced fluorescence intensity at room temperature. The 3D HPVF exhibits a pico molar range of detection from 10pM to 100pM with a 10pM limit of detection (LOD) for PDGF BB concentrations relevant for pregnant women predisposed to early-onset preeclampsia with clear differentiation when compared to similarly competing analytes PDGF AA and AB.

Protein cages are versatile platforms capable of encapsulating a wide range of nanoparticle cargo within biocompatible protein shells while providing tunable functionalities. Here, we investigated a self-assembly system that forms vesicle-like protein cages while simultaneously encapsulating nanoparticles at high density, yielding pomegranate-like protein- nanoparticle hybrid materials. Amphiphilic recombinant fusion protein building blocks based on elastin-like polypeptides, leucin zippers, and fluorescent proteins were employed to assemble vesicle-like protein cages via temperature-triggered liquid-liquid phase separation in the presence of fluorescent polystyrene nanoparticles. Analysis of nanoparticle encapsulation density and protein cage size indicates cooperative interactions between protein building blocks and nanoparticles that mediate the formation of protein-nanoparticle coacervate intermediates, which subsequently convert into core-shell hybrid protein cages, as further supported by kinetics studies. We demonstrate the self-assembly hybrid protein cages incorporating a fluorescent calcium sensor protein and titanium oxide nanoparticles, which exhibit a drastic enhancement in their calcium-sensing capability as a result of nanoparticle encapsulation. This platform offers a broadly applicable strategy that integrates protein biofunctionality with diverse nanoparticle properties for development of advanced hybrid materials.

Alginate hydrogels are widely used for biocompatible encapsulation due to their low cost, mild gelation conditions, and scalability; however, their limited mechanical strength and poor chemical stability under physiological conditions restrict their utility for oral delivery applications. In particular, the development of robust alginate formulations capable of surviving gastrointestinal salt and pH exposures is critical for advancing encapsulated microbial therapeutics for chronic kidney disease (CKD). In this study, we investigated the incorporation of ferric iron into calcium alginate networks as a strategy to enhance gel stability while maintaining biocompatibility. Using a three-ion competition approach, we achieved controlled introduction of ferric ions into calcium alginate gels without significantly altering bulk mechanical properties relative to standard calcium alginate. Although the initial ferric-containing gels displayed comparable modulus and structure, post-treatment with chitosan under mildly acidic conditions produced a dramatic increase in gel stability in physiological salt concentrations across both acidic and neutral pH environments. Ferric-containing gels formed at pH 4.6 absorbed negligible chitosan, in contrast to iron-free alginate gels, which incorporated substantial chitosan under identical conditions. These results support the formation of a thin, dense interfacial complex between chitosan, ferric ions, and alginate at the gel surface, which reinforces the matrix and inhibits dissolution. The resulting hybrid ferric-calcium alginate formulation enabled the production of sub-millimeter beads capable of encapsulating live Thauera aminoaromatica while preserving anaerobic p-cresol degradation activity at 37 {degrees}C using nitrate as an electron acceptor. Collectively, these findings establish ferric-modified alginate hydrogels as a promising, scalable platform for stable oral delivery of encapsulated microbial therapeutics.