ACS Applied Materials & Interfaces

Red-emitting carbon quantum dots (HP-CQDs) were synthesised for the first time from aqueous leaf extracts of Hamelia patens through single-step, reagent-free microwave-assisted carbonisation (750 W). The resulting nanoparticles displayed a narrow hydrodynamic size distribution centred at 3.9 nm, consistent with atomic force microscopy measurements showing a maximum height of 2.81 nm. Under 400 nm excitation, the CQDs exhibited a characteristic red emission maximum at 675 nm, representing a rare example of long-wavelength-emitting green CQDs derived from plant biomass. UV-Vis absorption bands at 224 and 256 nm were assigned to {pi}-{pi}* transitions of aromatic carbon domains and n-{pi}* transitions associated with carbonyl-containing surface groups, respectively. X-ray photoelectron spectroscopy (XPS) indicated a carbon-rich composition (C: 67.24%, O: 31.25%, N: 1.52%) with prominent C-O (42.67%) and C-C/C=C (42.64%) contributions. ATR-FTIR further confirmed the retention of hydroxyl, ether, and aliphatic functionalities following carbonisation. The excitation-wavelength-independent emission peak position implicates discrete surface molecular states rather than a heterogeneous distribution of emitters. HP-CQDs exhibit potent DPPH radical scavenging activity (IC50 = 141.8 {micro}g mL-1), comparable to ascorbic acid (IC50 = 114.8 {micro}g mL-1), and maintain >95% cell viability in both HeLa and RPE-1 cells up to 250 {micro}g mL-1. Confocal microscopy demonstrates concentration-dependent cytoplasmic accumulation and selective perinuclear localization at 300 {micro}g mL-1. In vivo biodistribution in zebrafish larvae confirms systemic uptake with statistically significant fluorescence enhancement at 500 {micro}g mL-1 (p < 0.01), establishing HP-CQDs as biocompatible red-fluorescent probes with dual imaging-antioxidant functionality. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=148 SRC="FIGDIR/small/724069v1_ufig1.gif" ALT="Figure 1"> View larger version (61K): org.highwire.dtl.DTLVardef@1dbe864org.highwire.dtl.DTLVardef@763ed0org.highwire.dtl.DTLVardef@115e9b9org.highwire.dtl.DTLVardef@1a3941e_HPS_FORMAT_FIGEXP M_FIG C_FIG

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

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

Cancer cell membrane coated biomimetic nanoparticles have been shown to be highly efficient in cellular uptake, homotypic tumour targeting, and the ability to suppress tumour growth compared to uncoated nanoparticles. Long duration anti-cancer treatment regimens require highly stable cancer cell membrane coated biomimetic nanoparticle. To manufacture such highly stable cancer cell membrane coated biomimetic nanoparticle, we used "Click-chemistry" to encapsulate cancer cell membrane on nanoparticles. In situ characterization was done to confirm the functionality of the novel Click-chemistry based formulation to encapsulate cancer cell membrane on nanoparticles. Gold nanoparticles were encapsulated with the cell membranes of cell lines of lung adenocarcinoma, malignant melanoma, high-grade serous epithelial ovarian cancer, colorectal cancer, oral cancer, esophageal adenocarcinoma, adenoid cystic carcinoma of salivary gland, and breast cancer. Functional group analysis, size, morphology, and surface charge confirmed long-stability of the biomimetic nanoparticles after incubating in complete growth medium for 12-months.

Cotton-based antimicrobial textiles are attractive for applications requiring improved microbiological control, but their performance depends on effective surface functionalization and retention of the active materials after use and washing. In this work, cotton fabrics were functionalized with hydroxyl-rich graphene oxide (HGO), hydroxyl-rich reduced graphene oxide (H-rGO), and silver nanowires (AgNWs), either individually or in combined treatments, to investigate their deposition onto the textile surface, washing resistance, and preliminary antibacterial activity. The treated fabrics were prepared by immersion-based coating procedures, and the persistence of the deposited materials after repeated washing was evaluated by UV-Vis analysis of the residual wash solutions. Surface morphology before and after washing was examined by scanning electron microscopy. The results showed that graphene-based coatings, particularly HGO, exhibited stronger retention on cotton fibers, while AgNWs were partially retained after repeated washing cycles. SEM images confirmed the deposition of AgNWs on the cotton surface and showed that part of the coating remained associated with the fibers after washing. A preliminary antibacterial assay against Escherichia coli indicated that nanomaterial-treated fabrics inhibited bacterial growth relative to untreated controls, with the combined HGO/AgNWs treatment showing the most promising inhibitory trend under the tested conditions. These findings demonstrate the feasibility of producing cotton fabrics functionalized with hydroxyl-rich graphene derivatives and silver nanowires, supporting their potential as proof-of-concept antibacterial textiles with partial washing resistance.

Manufacturing and storage processes can expose microbes to oxidative stress, reducing viability and limiting their use in biotechnological applications. Here, we evaluate graphene quantum dots (GQDs) containing hydroxyl and carboxyl groups as protective additives that mitigate peroxide-induced oxidative stress in Escherichia coli. GQDs did not adversely affect bacterial growth under basal conditions and restored growth in the presence of hydrogen peroxide. Using the membrane-partitioning fluorescent probe C11-BODIPY, we found that GQDs reduced peroxide-induced oxidation in bacterial membranes. We further used redox-sensitive roGFP2 probes to monitor intracellular oxidative stress and found that GQDs suppressed intracellular hydrogen peroxide accumulation and attenuated disruption of glutathione redox homeostasis. Together, these results show that GQDs protect bacteria by limiting peroxide-driven oxidative damage at both membrane and intracellular levels. This work supports the potential use of GQDs as protective additives for microbial formulations that are susceptible to oxidative stress.

Nowadays N95 facial mask has gain huge attention due to COVID19 pandemic situation and it serves as the prime PPE. Though the microbes can be restricted to get inside the human body due to the presence of mask temporarily, but over the time, bacteria and other microbes may get entrapped into the threads of the mask itself and thus acting as a storage chamber of microbes. It is necessary to eliminate them from the mask surface. To do so different floral structured Nano-ZnO with variable oriented arrangement of petals were fabricated on the surface of the N95 mask and further characterized through instrumentations including XRD, FTIR,UV-Vis, Fluorescence-Spectroscopy, SEM, DLS. The average crystallite size calculated for synthesized four different ZnO nanoflower were 25.19 nm, 23.46 nm, 27.27 nm and 31.78 nm (for glycerol, PEG, EDTA, Chitosan assisted) respectively. The antimicrobial activity was investigated by standard microbial broth dilution assay and Kirby-Bauer test which assured the inhibition of the bacterial growth. The MIC-MBC value of ZnO nanoflowers for E.coli and B. subtilis were found to be effective at dilution of 250 {micro}g/ml and 100 {micro}g/ml. Additionally a modified Kirby-Bauer assay has been designed to investigate the killing efficiency of the bacteria (E.coli). O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=145 SRC="FIGDIR/small/719592v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@a76030org.highwire.dtl.DTLVardef@9bf1b3org.highwire.dtl.DTLVardef@19232forg.highwire.dtl.DTLVardef@54fe68_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFig. - Graphical AbstractC_FLOATNO C_FIG

Conventional fluorescent imaging probes, including organic dyes and semiconductor quantum dots, suffer from inherent limitations such as photobleaching, cytotoxicity, poor aqueous dispersibility, and complex synthetic routes, necessitating the development of next-generation nanoscale fluorophores suitable for biological imaging. Carbon dots (CDs) have emerged as a compelling alternative owing to their nanoscale dimensions, tunable photoluminescence, excellent biocompatibility, and amenability to green synthesis from biomass-derived precursors. Herein, we report a comparative synthesis and systematic physicochemical evaluation of nitrogen-doped and undoped carbon dots derived from chamomile (Matricaria chamomilla L.) extract, prepared via solvothermal and microwave-assisted routes. Among the four synthesized variants--CM ST-U, CM ST-N, CM MW-U, and CM MW-N--the solvothermally synthesized nitrogen-doped carbon dots (CM ST-N) exhibited markedly superior optical performance, characterized by a high fluorescence quantum yield of 57.2%, which is among the highest reported for biomass-derived nitrogen-doped carbon dots. Comprehensive characterization using UV-visible spectroscopy, photoluminescence (PL) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), dynamic light scattering (DLS), zeta potential analysis, and atomic force microscopy (AFM) confirmed the nanoscale dimensions (~8.3 nm), surface-rich functional groups, successful nitrogen incorporation (10.86 %), and moderate colloidal stability (zeta potential: -17.3 mV). Photoluminescence stability studies across seven solvent systems including biologically relevant media--phosphate-buffered saline (PBS), Dulbeccos modified Eagles medium (DMEM), and serum-free medium (SFM) demonstrated sustained fluorescence emission over 72 hours. In vitro cytotoxicity assessment using the MTT assay on RPE-1 retinal pigment epithelial cells confirmed high cell viability (>70%) across a broad concentration range (10-500 {micro}g mL-1) over multiple exposure durations. Collectively, these results establish CM ST-N as a highly fluorescent, biocompatible, and colloidally stable nanoprobe with strong potential for fluorescence-based bioimaging applications.

Curcumin is a naturally occurring polyphenol that demonstrates considerable anti-cancer activity, however the aqueous insolubility, rapid metabolism and relatively low bioavailability are limiting to its clinical application. As such, a curcumin-magnesium (Cur-Mg) coordination complex was synthesized and subsequently encapsulated within DNA hydrogels (Cur-Mg-Hgel). The Cur-Mg complex was fully characterized using UV-Vis spectroscopy, FTIR and X-ray diffraction (XRD). UV-Vis, FTIR and XRD all support the formation of a coordination complex and suggest a decreased level of crystallinity compared to free curcumin. DNA hydrogels were formed and characterized using atomic force microscopy, rheology and swelling kinetic studies. In vitro cytotoxicity studies utilizing an MTT assay demonstrate dose dependent inhibition of HeLa cell proliferation and a slightly better retention of RPE-1 viability at low concentrations (suggesting some difference in sensitivity) though significant cell death is seen at higher concentrations and both cells. Intracellular production of ROS was measured using the DCFH-DA assay and is seen to increase when HeLa cells are treated with Cur-Mg-Hgel in comparison to un-treated controls. Annexin V/PI staining demonstrates primarily late or early apoptotic activity with minimal necrosis following treatment with Cur-Mg-Hgel. The evidence presented strongly supports the notion that Cur-Mg-Hgel is a ROS-modulating, pro-apoptotic Hydrogel suitable for cancer treatment. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=102 SRC="FIGDIR/small/724072v1_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@18727aeorg.highwire.dtl.DTLVardef@3e20adorg.highwire.dtl.DTLVardef@d3703eorg.highwire.dtl.DTLVardef@16e260e_HPS_FORMAT_FIGEXP M_FIG C_FIG

Ternary composite systems formed by lactoferrin (LF), sodium alginate (Alg), and Fe(II) were designed to investigate their potential as an iron delivery platform with enhanced protein stability. The ternary LF-Alg-Fe (LAF) composites demonstrated distinct structures depending on the LF to Alg ratio and the Fe(II) concentrations. At an LF to Alg ratio of 8:2 and final Fe concentrations between 20-30 mM, the system formed complexes stabilized by electrostatic interactions. Whereas Alg-rich formulations formed hydrogels stabilized by Alg-Fe(II) egg-box cross-linking. Rheological analysis and swelling behavior indicated a higher mechanical strength in LF-rich complexes and stronger network integrity in Alg-rich hydrogels, while intermediate LF/Alg ratios showed weaker structures overall. Fourier-transform infrared spectroscopy (FTIR) spectra showed no changes in functional groups or polymer structures after composite formation, confirming composite formation via non-covalent interactions. Thermal studies indicated that these ternary systems improved LF stability, evidenced by preserved secondary structure after heating using circular dichroism (CD), and an increased denaturation temperature compared with free LF in differential scanning calorimetry (DSC). In addition, in LF-rich formulations the Fe(II) release in aqueous solution was [~]50% while in Alg-rich formulations it was much lower (< 10%). LF-Alg-Fe composites exhibit distinct structures governed by protein-polysaccharide interactions and iron-mediated cross-linking, providing a potential strategy for protein stabilization and iron fortification in food systems.

The optimization of mRNA-lipid nanoparticles (mRNA-LNPs) for therapeutic applications is limited in part by the inadequate characterization of mRNA payload heterogeneity. One current challenge is accurately measuring the number of mRNA copies within individual LNPs, where the standard method of intensity-based mRNA number determination is sensitive to fluorescent dye-dye interactions and heterogeneity of mRNA labeling. Here we present a single-particle microscopy method that combines direct counting of the mRNA copies per LNP with LNP size measurements. While confined in microwells, individual mRNA-LNPs are lysed to release their cargo and stained with a dye such that the number of mRNA molecules in each well can be directly counted using fluorescence microscopy. Since the method stains the mRNA cargo in situ, it enables characterization of LNPs formulated with therapeutic grade (e.g., unlabeled) mRNA. We applied this approach to two Onpattro(R)-based LNP formulations prepared using different formulation buffers, where the two formulations had different average mRNA copy number, particle size, and fraction of LNPs lacking mRNA. The ability to directly count the number of mRNA molecules in LNPs establishes a complimentary method to intensity-based mRNA number determination and supports the characterization and screening of clinically relevant LNP formulations.

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.

Tomographic volumetric printing (TVP) enables rapid fabrication of complex, centimeter-scale 3D architectures. TVP of pristine proteins like collagen is attractive because it better preserves native bioactive motifs that regulate cell-matrix signaling. However, direct TVP of collagen remains challenging because dityrosine crosslinking, driven by visible-light-activated Ru(II)bpy32+/sodium persulfate (SPS), lacks an effective inhibitory mechanism. This results in near-immediate crosslinking upon exposure to light, which leads to an insufficient nonlinear threshold response that fails to suppress background curing. Here, we introduce vitamin C (L-ascorbic acid) as a biocompatible redox regulator to overcome this limitation. UV-Vis kinetics demonstrate that vitamin C suppresses Ru(III) accumulation and scavenges persulfate radicals within Ru/SPS system. This dual action generates a critical photo-redox and crosslinking threshold that inhibits dityrosine formation until vitamin C is depleted. Thereby the threshold response needed for TVP is successfully established, which enables high-fidelity volumetric printing of native collagen. Post-printing construct densification ([~]53% shrinkage) further improves feature resolution (80 {micro}m positive; 120 {micro}m negative) and yields mechanically stable and highly stretchable hydrogels (up to 180% strain). Collagen resin with vitamin C supports both cell seeding post-printing and cell-laden printing with high cell density and viability, enabling the rapid biofabrication of cell-instructive 3D microenvironments. Table of Contents (ToC) O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=37 SRC="FIGDIR/small/717972v1_ufig1.gif" ALT="Figure 1"> View larger version (15K): org.highwire.dtl.DTLVardef@742a83org.highwire.dtl.DTLVardef@930c06org.highwire.dtl.DTLVardef@1fa7f08org.highwire.dtl.DTLVardef@aa22bb_HPS_FORMAT_FIGEXP M_FIG C_FIG Tomographic volumetric printing (TVP) of native proteins is limited by uncontrolled background crosslinking. Here, vitamin C is introduced as a biocompatible redox-regulator to establish a tunable nonlinear polymerization threshold response for TVP. This strategy effectively suppresses background crosslinking and enables high-fidelity printing of pristine collagen. Subsequent post-print densification yields robust, elastic, and cell-compatible constructs with enhanced resolution for tissue engineering applications.

The emergence of antimicrobial resistance has been rapid, necessitating the development of alternative therapeutic approaches beyond traditional antibiotics. In this proof-of-concept study, we examined the antibacterial activity of citrate-stabilized, colloidally aggregated silver nanoparticles (AgNPs) against Escherichia coli by combining physicochemical characterization with experimental antibacterial testing The synthesis of silver nanoparticles was done through a modified thermal citrate reduction protocol, and UV-visible spectroscopy, dynamic light scattering (DLS), and zeta potential were used to characterize the nanoparticles. Spectroscopy analysis showed a clear surface plasmon resonance peak at 310-320 nm, indicating the formation of nanoparticles. DLS measurements showed that the dominant hydrodynamic diameter was around 250-270 nm, which is indicative of controlled colloidal aggregation, and near-neutral values of zeta potential indicated steric stabilization of the nanoparticle clusters. Agar tests demonstrated a clear zone of inhibition, and broth cultures showed a lower turbidity and slower bacterial growth with AgNPs. The above findings suggest that nanoparticles that are colloidally aggregated maintain a significant antimicrobial activity even though the surface area is lower than that of monodispersed systems. Mechanistically, the observed antibacterial effect can be explained by a multi-modal effect through direct membrane disruption, localized release of silver ions, and the induction of oxidative stress pathways in bacterial cells. The aggregated form could also help to increase the nanoparticle cell interactions through the provision of multivalent contact points of nanoparticles, and thus the antibacterial efficacy. Controlled colloidal aggregation of AgNPs is a promising approach to the development of effective and possibly more stable antimicrobial agents. These results indicate the possibilities of aggregated nanoparticle systems in fighting drug-resistant pathogens and a basis on future studies of its clinical use.

Detergent-free extraction of membrane proteins using polymers directly into nanodiscs from the cell membrane has been used widely in recent years. Since the first use of poly(styrene-co-maleic acid) (SMA), numerous related polymers have been developed that differ in chemical architecture and nanodisc characteristics, each capable of influencing the structural and functional properties of the encapsulated membrane protein and its surrounding lipids. Identifying an optimal solubilising polymer, therefore, requires consideration not only of extraction efficiency but also compatibility with downstream applications and analyses. Polymer series in which a single parameter is systematically varied provide a valuable, nuanced tool for optimising nanodisc utility in downstream applications. This study utilises a chemically defined series of poly(styrene-co-maleic acid-co-(N-benzyl)maleimide) (BzAM) terpolymers that exhibit a stepwise, systematic increase in hydrophobicity. Using the human calcitonin gene-related peptide (CGRP) receptor as an exemplar class B1 G-protein-coupled receptor (GPCR), the ability of each BzAM terpolymer to solubilise the receptor from mammalian cell membranes was assessed. All members of the series successfully solubilised CGRP receptor, with solubilisation efficiency correlating positively with increasing hydrophobicity. Importantly, the receptor retained its characteristic high-affinity ligand-binding capability when encapsulated within the BzAM nanodisc, demonstrating that functional integrity is preserved following BzAM-mediated extraction and purification. These findings establish the BzAM terpolymer series as a systematic, tuneable, well-defined tool for the detergent-free solubilisation and functional investigation of GPCRs, and other membrane proteins, in near-native lipid environments. HIGHLIGHTSO_LIStepwise-tuned poly(styrene-co-maleic acid-co-(N-benzyl)maleimide) (BzAM) terpolymers provide a chemically defined, hydrophobicity-controlled platform for detergent-free membrane protein extraction. C_LIO_LIAll BzAM variants effectively solubilise the human calcitonin gene-related peptide (CGRP) receptor, with extraction efficiency increasing in line with terpolymer hydrophobicity. C_LIO_LICGRP receptor maintains high-affinity ligand binding in BzAM nanodiscs, demonstrating preservation of ligand-binding function after solubilisation. C_LIO_LIThe BzAM series provides a novel platform for studying G-protein-coupled receptors and other membrane proteins in near-native lipid environments, with the potential to deliver mechanistic insights and support future drug-discovery efforts. C_LI GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=110 SRC="FIGDIR/small/726474v1_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@1cb167corg.highwire.dtl.DTLVardef@313e60org.highwire.dtl.DTLVardef@f64a2borg.highwire.dtl.DTLVardef@17f6629_HPS_FORMAT_FIGEXP M_FIG C_FIG

Multidrug resistant (MDR) bacterial wound infections are an increasing clinical challenge and require alternatives to conventional antibiotics. Although antimicrobial proteins offer promise, their therapeutic use is limited by poor stability, proteolytic degradation, reduced activity under physiological conditions, and potential toxicity. This work reports pH-sensitive lipid nanocarriers composed of granulysin (GNLY) and oleic acid (OA) for antimicrobial delivery to infected tissues. At neutral pH, GNLY is retained within OA-based nanocarriers and protected from proteolytic degradation. At pH 5.0, such as in infected wounds, the carriers undergo structural reorganization and release GNLY, restoring antimicrobial activity. OAGNLY (32 {micro}g/mL) achieved >3-log reductions in Staphylococcus aureus and Escherichia coli within 1 hour, and up to 4-log reductions in Pseudomonas aeruginosa and Acinetobacter baumannii, at physiological salt concentrations where free GNLY was largely inactive. Minimum inhibitory concentrations were 16 {micro}g/mL for MRSA and 32 {micro}g/mL for colistin-resistant E. coli. Ultrastructural analysis using transmission electron microscopy revealed disruptions of bacterial membranes and intracellular structures following OAGNLY treatment. In a murine surgical wound infection model, topical application of OAGNLY for 4 hours reduced bacterial burden by >5 logs and significantly decreased inflammation, as confirmed by histological analysis. In parallel, OAGNLY demonstrated minimal cytotoxicity to mammalian cells at active concentrations. These findings identify OAGNLY nanocarriers as a promising platform for pH-responsive delivery of GNLY and highlight their potential application for treating MDR skin and soft tissue infections..

Ion channels are pore-forming transmembrane proteins that allow ions to move down an electrochemical gradient and across the channel pore and regulate many cell functions. Among them, are the G-protein-gated inwardly-rectifying K+ channels 1 (GIRK1) that are ubiquitously expressed with major functions in the brain and heart. Interestingly, significantly higher GIRK1 expression has been found in estrogen receptor positive (ER+) breast cancer patients compared to patients with HER2+ tumors or normal patients, and that was statistically correlated with shorter survival times and metastatic potential. Herein, we report the preparation of [~]4 nm GAT1508-coated poly(ethylene glycol) gold nanoparticle (PEGylated AuNP) biomarker for ER+ breast cancer cell screening through an optical microscope. A urea-based small molecule, GAT1508, with an N-methylpyrazole benzyl group on one side and a bromo-thiophene tail on the other side, has been shown to predominantly bind GIRK1 subunits and specifically activate GIRK1/2 channels. Two derivatives of GAT1508were synthesized and characterized: an ethylamine derivative (GAT1508-EA) with a chain extension from the benzyl ring, and a propylamine derivative (GAT1508-PA) with a chain extension from the pyrazole ring. Electrophysiology (TEVC and whole-cell patch-clump) experiments as well as fluorescence studies (Thallium assay) showed that only GAT1508-PA inhibited GIRK1/2-mediated K+ currents in transfected HEK293GIRK1 cells. Docking studies showed strong binding for the propylamine GAT1508 derivative, both in the amine form (GAT1508-PA) as well as in the amide form (GAT1508-PA-EG2; coupled with PEG as in the AuNPs). GAT1508-PEG-AuNPs (GAT1508-NPs) were synthesized subsequently with [~]65 wt% metal loading. UV-Vis studies revealed the presence of the conjugated ligand at 260 nm. Flow cytometry studies showed binding of Alexa 594-labeled GAT1508-NPs in ER+ MCF-7 breast cancer cells with a strong interaction, while incubation of fixed MCF-7 cells with a GAT1508-NP solution led to optical detection of ER+ breast cancer cells, without the need of fluorescent dyes and additional amplification steps. Detection was not feasible in MDA-MB-231 cells, a triple (-) breast cell line that does not express GIRK1. This is the first study, to our knowledge, that couples nanotechnology with small molecule drug design and electrophysiology to develop ion channel-tracing molecular probes for the detection/screening of ER+ breast cancer.

Lipid nanoparticles (LNPs) have demonstrated strong potential in COVID-19 mRNA vaccines nevertheless they still face the challenges in low mRNA delivery efficacy. Virus-like porous silica (VLPSi) nanoparticles (NPs) represent a promising biomimetic delivery platform because their spiked morphology may enhance cellular internalization and promote endosomal membrane disruption. However, the application of VLPSi for mRNA has been rarely explored. In this study, hybrid lipid-VLPSi NPs were developed by combining VLPSi with either lipoplexes (LPs) or LNPs. The effects of lipid types, mass ratio of different compositions, and amine modifications of VLPSi on mRNA delivery were studied. The results demonstrated that both LP and LNP could be successfully integrated with VLPSi to form hybrid delivery systems for mRNA transfection. VLPSi could significantly enhance mRNA delivery of both LPs and LNPs due to improved cellular uptake, structural stabilization of the mRNA complex, and enhanced endosomal escape mediated by the rigid virus-like surface architecture. Among the tested lipid formulations, the ionizable lipid ALC-0315 and helper lipid DOPE with mass ratio of 5:3 was the most effective lipid composition to be integrated with VLPSi, showing the highest mRNA delivery performance. In addition, amino modification of VLPSi was found to be a critical factor for efficient mRNA delivery. Hybrid LNPs containing amino-modified VLPSi showed significantly higher transfection efficiency than those containing unmodified VLPSi. Notably, amino-modified LNP-VLPSi achieved up to fivefold higher gene expression than conventional LNPs. Overall, this study establishes VLPSi as an efficient platform for amplifying lipid-mediated mRNA delivery. Owing to its straightforward integration into widely used LNP systems, VLPSi offers an adaptable and effective strategy for advancing next-generation mRNA therapeutics.

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

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.