Back

Journal of Nanobiotechnology

Springer Science and Business Media LLC

Preprints posted in the last 30 days, ranked by how well they match Journal of Nanobiotechnology's content profile, based on 14 papers previously published here. The average preprint has a 0.01% match score for this journal, so anything above that is already an above-average fit.

1
Plasma membrane-associated graphene oxide as aplatform for modulating signalling through cell-surfacereceptors: an integrin-focused proof-of-concept study

Karakasidi, A.; Lozano, N.; Kostarelos, K.; Vranic, S.

2026-08-26 cell biology 10.64898/2026.08.25.747094 medRxiv
Top 0.1%
14.9%
Show abstract

Graphene oxide (GO) has primarily been investigated as a carrier for intracellular delivery of therapeutic molecules. In previous work, we identified a cell type-dependent interaction pattern in which GO remained predominantly associated with the plasma membrane of cancer cells but was internalised by non-cancerous epithelial cells. Here, we explored whether plasma membrane-associated GO can be used as a platform to present bioactive ligands and influence cell-surface receptor signalling in cancer cells. To test this hypothesis, we targeted integrin receptors at the plasma membrane in glioblastoma cell models using an RGD-containing peptide non-covalently complexed with GO. We assessed GO-peptide interactions, cellular interactions/uptake, motility, and focal adhesion signalling readouts. Peptide association was quantified using a 2,4,6-trinitrobenzene sulfonic acid (TNBSA) assay, and GO was characterised by atomic force microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and colloidal measurements. Immediately after complexation, ~70% of RGD was associated with GO. Peptide association increased the nitrogen signal and shifted the principal GO XRD peak while retaining nanosheet morphology. Biological responses were examined in U87 and U251 glioblastoma cells with different integrin-positive fractions, and in non-cancerous BEAS-2B bronchial epithelial cells. Confocal microscopy showed that GO and GO:RGD remained predominantly localised on the plasma membrane in U87 and U251 cells, whereas greater intracellular localisation was observed in BEAS-2B cells. Importantly, GO:RGD significantly reduced key indicators of cell motility: cell velocity in U87 and U251 cells, with trajectory and mean-square-displacement analyses supporting restricted cellular movement. Free RGD had no significant effect, while GO alone produced a smaller reduction in motility only in U251 cells. No treatment significantly altered BEAS-2B motility. Flow cytometry also showed a reduced pFAK-associated signal in GO:RGD-treated U87 cells. These findings establish a proof of concept that the cell-line-dependent plasma membrane localisation of GO can be exploited as a membrane-associated nano-bio interface for cell-surface-active ligands, opening the way for the development of GO-based platforms that modulate receptor-mediated signalling and cell behaviour.

2
Phytometabolite-Enriched Edible Plant-Derived Extracellular Vesicles Exhibit Source-Specific Bioactives with Distinct Pharmacological Potential

Subudhi, P. D.; Jakhmola, V. R.; Sureshan, S. C.; Yenuganti, V. R.; Saroj, N.; Gautam, S.; Sinha, P.; Bihari, C.; Sarin, S. K.; Baweja, S.

2026-08-20 pharmacology and toxicology 10.64898/2026.08.17.742983 medRxiv
Top 0.1%
10.1%
Show abstract

Edible plant derived extracellular vesicles (PDEVs) are emerging as biocompatible, orally deliverable nanocarriers with therapeutic potential; however, their phytometabolite cargo, gastrointestinal stability, and source specific biological functions remain poorly characterized. Here, PDEVs were isolated from four phytochemically distinct plant based foods (black carrot, ginger, garlic, and turmeric), selected for their diverse bioactivity, and characterized by transmission electron microscopy, nanoparticle tracking analysis, and zeta potential. Gastrointestinal stability was evaluated in simulated digestion model. Source specific phytometabolites were profiled by untargeted LC MS MS metabolomics. Functionally validated in ammonia stressed epithelial cells and steatotic hepatocytes. PDEVs exhibited characteristic cup shaped morphology with particle sizes ranging from 60 to 214 nm and zeta potentials of -6.0 to -49.0 mV. PDEVs retained colloidal stability, supporting their suitability for oral delivery. We identified 572 phytometabolites with distinct source specific signatures, including lignin and quercetin in carrot EVs, [6] gingerol and silymarin in ginger EVs, diosgenin in garlic EVs, and curcumin in turmeric EVs. These metabolites found associated to antioxidant, anti inflammatory, epithelial barrier, lipid metabolic, and apoptotic pathways. Functional validation demonstrated carrot EVs significantly enhanced epithelial barrier integrity by increasing claudin (>8-fold, p<0.05), occludin (>2-fold, p<0.05). Ginger EVs restored ZO 1 while suppressing cyclin D1 and MMP9(p<0.05). Garlic and turmeric EVs attenuated inflammatory signaling by reducing STAT3, AKT1, and TNF , whereas turmeric EVs additionally decreased caspase 3 and PTGS2(p<0.01). In steatotic hepatocytes, garlic EVs significantly reduced PNPLA3 (p<0.001) and SREBP 1c while increasing PPAR- (p=0.002). Hence, our results indicate that edible PDEVs are gastrointestinally stable, phytometabolite enriched nanocarriers with distinct source specific functional properties, supporting their potential as orally deliverable nutraceuticals for improving gut liver functions.

3
Mechanistic Insights into Magnesium Pyrophosphate Formation in the Presence of Gold Nanoclusters Enable Genetic Analysis via Co-Aggregation-Induced Fluorescence Enhancement

Grammatikos, S.; Alexaki, K.; Gizeli, E.

2026-08-13 molecular biology 10.64898/2026.08.12.744482 medRxiv
Top 0.1%
5.2%
Show abstract

The formation of magnesium pyrophosphate (Mg2P2O7) in nucleic acid amplification and cell-free transcription systems has attracted considerable attention, since Mg2P2O7 serves as a reliable indicator of reaction efficiency. However, real-time monitoring of Mg2P2O7 remains challenging, relying largely on time-consuming analytical techniques or end-point detection methods. Here, we report a Mg2P2O7-driven co-aggregation mechanism involving glutathione-capped gold nanoclusters (GSH-AuNCs) that induces fluorescence enhancement, enabling real-time crystal formation monitoring. The mechanism was first investigated in simplified mixtures containing pyrophosphate (P2O74-) and magnesium (Mg2+) ions. Real-time fluorescence profiles revealed that the GSH-AuNCs/Mg2P2O7 co-aggregation can be correlated with crystal formation/growth/solubilization and solution turbidity, while distinct kinetic patterns can be indicative of the crystal size at the end of the reaction. As a next level of complexity, we examined the effects of common components in an enzymatic amplification reaction, i.e., dithiothreitol (DTT), ammonium sulfate ((NH4)2SO4), deoxynucleotides (dNTPs) and Bst polymerase, on Mg2P2O7 formation through real-time GSH-AuNCs fluorescence variations. Guided by the above results, we studied and selected the experimental parameters for the design of an optimized qualitative (end-point) or quantitative (real-time) genetic test. Finally, the loop-mediated isothermal amplification (LAMP) was used as a platform to demonstrate the quantification of Influenza A RNA within the range of 102-108 copies/reaction. The resulting one-tube, contamination-free assay was shown to have a response time of <25 min even in a crude saliva sample. Beyond diagnostics, this crystallization-activated fluorescence strategy may also support real-time investigation of Mg2P2O7 formation in other biotechnological processes, including in vitro transcription and Mg2P2O7-bioorganic composites synthesis. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=80 SRC="FIGDIR/small/744482v1_ufig1.gif" ALT="Figure 1"> View larger version (37K): org.highwire.dtl.DTLVardef@96dd88org.highwire.dtl.DTLVardef@aa122dorg.highwire.dtl.DTLVardef@18f4abforg.highwire.dtl.DTLVardef@745f1e_HPS_FORMAT_FIGEXP M_FIG C_FIG

4
EV-Tracer enables lineage-resolved detection and molecular profiling of extracellular vesicle-associated signals in cancer-fibroblast co-culture

Naito, Y.; Hori, C.; Yoshida, K.; Amano, T.; Yashiro, M.; Yanagihara, K.; Honda, K.

2026-08-26 cell biology 10.64898/2026.08.25.746941 medRxiv
Top 0.1%
3.3%
Show abstract

Extracellular vesicles (EVs) facilitate intercellular communication by transferring diverse bioactive molecules from donor to recipient cells. However, EVs released by distinct cellular lineages become difficult to distinguish when mixed in multicellular experimental models, limiting the analysis of how cell-cell interactions affect EV-associated molecular profiles. To address this, EV-Tracer, a CD63-based dual-fluorescence tracing and capture system for detecting, isolating, and profiling lineage-associated EV fractions, was developed. Achilles or mScarlet was inserted into the small extracellular loop of CD63, enabling tracer-specific EV detection by digital counting, antibody-based isolation, and live-cell visualisation. Exploratory EV RNA sequencing suggested that physical cell-cell contact was associated with distinct EV RNA profiles, including interferon-related signals, which were supported by targeted cellular and EV-associated RNA analyses. EV-Tracer provides a practical framework for investigating lineage-associated EV dynamics and molecular signals in mixed-cell systems.

5
Lipid anchor engineering controls cell-penetrating arginine-rich peptide presentation for efficient siEGFR liposomal delivery to triple-negative breast cancer cells

Bialecki, P.; Braccia, S.; Makowski, T.; Piorecka, K.; Falcigno, L.; Bellavita, R.; Falanga, A.; Bryszewska, M.; Robaszkiewicz, A.; Galdiero, S.; Pedziwiatr-Werbicka, E.

2026-08-25 biophysics 10.64898/2026.08.20.745705 medRxiv
Top 0.1%
3.2%
Show abstract

Understanding the physicochemical factors that govern siRNA nanocarrier assembly is essential for the rational design of effective delivery systems. By optimizing various lipid compositions, cholesterol content and PEG length we created a peptide-functionalized cationic liposomal platform made of DOPE/TAP lipids with cholesterol-anchored nona-arginine (R9-Chol) for siRNA complexation, intracellular transport and effective silencing of the target EGFR gene. Analysis of {zeta}-potential and dynamic light scattering allowed to rationally design formulation of stable, monodisperse nanoscale lipoplexes with a positive surface charge. With fluorescence polarization, circular dichroism and agarose gel electrophoresis we found an optimal siRNA:liposome complexation ratio of 1:77, which protected siRNA from ribonuclease-mediated degradation. Morphological imaging confirmed a shift from discrete vesicular structures to organized multilamellar lipoplexes, consistent with electrostatically driven self-assembly. In cellular studies, the optimized nanocarrier promoted efficient uptake of fluorescent siRNA in MDA-MB-231 cells and achieved functional delivery of anti-EGFR, leading to substantially reduced expression of the target gene at both transcript and protein levels. This work offers mechanistic understanding of peptide-assisted lipid:siRNA assembly and positions R9-functionalized DOPE/TAP liposomes as a promising platform for siRNA delivery.

6
3D Printed X-ray Compatible Microfluidics for Online Characterization of Hexosomes: A Synchrotron SAXS-on-Chip Study with Molecular Dynamics Insights

Babaie, Z.; Valerio, M.; Schuhmann, F.; Dimaki, M.; Rezaei, B.; Pezeshkian, W.; Keller, S. S.; Svendsen, W. E.; Souza, P. C. T. d.; Yaghmur, A.

2026-09-01 biophysics 10.64898/2026.08.31.748233 medRxiv
Top 0.1%
2.7%
Show abstract

Online structural characterization during microfluidic lipid self-assembly is important for understanding and controlling the formation of nonlamellar liquid crystalline nanodispersions. Here, we report a 3D-printed, X-ray-compatible hydrodynamic flow-focusing microfluidic chip with variable channel dimensions, integrated with synchrotron small-angle X-ray scattering (SAXS), for position-resolved SAXS-on-chip monitoring of Ca2+-triggered hexosome formation. Hexosomes were produced under continuous flow by mixing ethanolic solutions of docosahexaenoic acid monoglyceride (MAG-DHA), the negatively charged phosphatidylglycerol DOPG, and -tocopherol with Ca2+-containing PIPES buffer. Online SAXS-on-chip measurements detected three Bragg reflections characteristic of the internal inverse hexagonal (H2) phase on a tens-of-milliseconds residence-time scale, revealing rapid structural evolution during microfluidic mixing. Complementary ex situ SAXS identified the DOPG/Ca2+ molar ratio as a key parameter modulating the direct vesicle-to-hexosome transformation and the compactness of the internal H2 nanostructures. Dynamic light scattering showed that the flow-rate ratio modulated nanoparticle size, yielding hexosomes with mean hydrodynamic diameters in the range of approximately 120-175 nm and polydispersity index values down to 0.14 at a total flow rate of 200 {micro}L min-1. Cryo-TEM revealed coexistence of hexosomes and vesicular nanostructures, highlighting morphological heterogeneity, while Coarse-Grained Molecular Dynamics simulations supported a central role of Ca2+-DOPG association in promoting a direct lamellar-H2 phase transition. Overall, this work shows that 3D-printed SAXS-compatible microfluidics can integrate continuous production with online structural characterization, providing a basis for future formulation and process optimization of drug-loaded cubosomes, hexosomes, and related nonlamellar liquid crystalline nanodispersions.

7
TROP2-targeting chimeras (TRTACs) for tumor-selective membrane protein degradation and enhanced drug delivery

Chen, L.; Fu, X.; Dong, W.; Deng, X.; Chen, S.; Wang, F.; Zhao, J.; Shao, S.; Fan, L.; Zhang, J.; Zhang, L.

2026-08-20 cell biology 10.64898/2026.08.19.745708 medRxiv
Top 0.1%
2.4%
Show abstract

Extracellular targeted protein degradation (eTPD) systems typically utilize lysosome-targeting receptors (LTRs) to mediate internalization and lysosomal degradation of extracellular and membrane proteins. While multiple LTRs have been discovered, there remains a compelling need to seek for new LTRs, particularly those with clear clinical relevance, to expand the therapeutic potential of eTPD. Here we report trophoblast cell surface antigen-2 (TROP2), a clinically validated tumor-associated antigen, as a promising tumor-selective LTR. We engineer TROP2-targeting chimeras (TRTACs) by genetically fusing a TROP2-binding nanobody to nanobodies against specific target proteins. We show that TRTACs can induce tumor cell-selective degradation of diverse membrane proteins, including epithelial growth factor receptor (EGFR), human epithelial growth factor receptor 2 (HER2), and programmed death-ligand 1 (PD-L1). The EGFR-targeted TRTAC significantly inhibits tumor cell proliferation and shows potent antitumor activity in vivo. We further design TRTAC-drug conjugates (TRTAC-DCs) by attaching cytotoxic payloads to TRTACs, enabling targeted protein degradation together with enhanced drug delivery. TRTAC-DCs show significantly enhanced activity against HER2- and EGFR-positive tumors both in vitro and in vivo, with minimal toxicity observed in normal tissues. These findings establish TROP2 as a robust LTR and provide a versatile eTPD platform with profound translational potential for tumor treatment.

8
Improved diagnostic identification of urothelial carcinoma through solid-state nanopore determination of urinary hyaluronan size distribution

Erxleben, D. A.; Poddar, S.; Rodriguez, C. M.; Williams, P. H.; Davis, M. A.; Davis, R. L.; Green, D. E.; DeAngelis, P. L.; Rahbar, E.; Khvatkova, E. S.; Langefeld, C. D.; Hall, A. R.

2026-08-13 urology 10.64898/2026.08.12.26360208 medRxiv
Top 0.1%
2.2%
Show abstract

Urothelial carcinoma (UC) is among the most common malignancies worldwide and is known to exhibit a high recurrence rate. The relative lack of validated, non-invasive biomarkers for the disease challenges early detection and negatively impacts patient outcomes. The linear polysaccharide hyaluronan (HA) has been recognized as a potential source of diagnostic information for UC, with its urinary concentration shown to be predictive of disease severity. Here, we use solid-state nanopore (SSNP) sensing to investigate the value of urinary HA size distribution as an independent and complementary predictor of UC. We show that, when combined with urinary concentration, HA size distribution provides a significant improvement to the differentiation of healthy individuals from those with urinary tract diseases in general (AUC = 0.91, p < 0.05), as well as differentiation of individuals with UC from those without (AUC = 0.87, p < 0.05). These results establish the potential of SSNP-based HA profiling for non-invasive diagnostics of UC.

9
Novel Dissymmetric Ionizable Lipid-Assembled Lipid Nanoparticles for Delivery of Ferroptosis-Related siRNA in Diabetic Treatment

Zhang, H.; Liu, Y.; He, F.; Xue, G.; Kang, Y.; Zhang, Z.; Ma, J.; Xiao, J.; Meng, Q.

2026-09-01 pharmacology and toxicology 10.64898/2026.08.26.747432 medRxiv
Top 0.1%
1.8%
Show abstract

Small interfering RNA (siRNA) enables precise post-transcriptional gene silencing for refractory diseases, yet its clinical translation remains limited by the lack of safe and efficient delivery vectors. Inspired by the dissymmetric alkyl chain architecture of natural membrane phospholipids, we designed and synthesized 34 novel ionizable lipids with dissymmetric hydrophobic tails and formulated them into lipid nanoparticles (LNPs). Through systematic physicochemical and biological assessments, we established clear structure-activity relationships and identified two lead LNPs (O14-LNP, H18a-LNP) with superior endosomal escape capacity, enhanced in vivo gene silencing potency, and favorable biosafety relative to the clinical benchmark MC3-LNP. In both streptozotocin-induced and spontaneous db/db type 2 diabetes (T2D) mouse models, lead LNPs delivering ferroptosis-related siRNAs effectively ameliorated glucose and lipid metabolic disorders, restored islet function, and alleviated hepatic steatosis. This study not only lays a theoretical foundation for the rational design of novel ionizable lipids, but also validates the therapeutic potential of siRNA therapy targeting ferroptosis, providing a versatile delivery platform and targeted therapeutic strategy for the treatment of T2D.

10
Label-free Isolation of Heterogeneous Breast Cancer Cell Populations via Insulator-Based Dielectrophoresis

Ozkayar, G.; Usman, I. N.; Yakin, E.; Kraan, J.; David, K.; Bosma, D.; Martens, J. W.; ten Dijke, P.; Pesch, G. R.; Boukany, P. E.

2026-08-10 cancer biology 10.64898/2026.08.04.742571 medRxiv
Top 0.2%
1.4%
Show abstract

Circulating tumor cells (CTCs) are valuable biomarkers for cancer diagnosis and monitoring, yet their isolation from blood remains challenging due to their phenotypic heterogeneity and rarity. Label-free microfluidic technologies offer a promising alternative to affinity-based approaches by exploiting intrinsic biophysical differences between cell types. Here, we developed a microfluidic platform for label-free cell separation based on insulator-based dielectrophoresis (iDEP). The microfluidic device employs an array of triangular insulating structures that generate strong electric field gradients in response to an externally applied alternating current (AC) electric field, enabling selective isolation of breast cancer cells from blood cells based on their dielectric properties. Hydrodynamic focusing is used to confine the sample stream and precisely control cell trajectories within the separation region. Numerical simulations were performed to optimize the electric field distribution and fluid flow characteristics within the device. Experimental validation using breast cancer cell lines (mesenchymal-like MDA-MB-231 cells and epithelial-like MCF-7 cells) spiked into peripheral blood mononuclear cells (PBMCs) demonstrates selective dielectrophoretic deflection of cancer cells while PBMCs largely follow the central streamline. The platform achieves recovery rates exceeding 98% and a separation purity above 65% within the optimized operating conditions. The proposed system provides a simple label-free approach to separate heterogeneous cell populations and represents a promising tool for microfluidic liquid biopsy enrichment applications.

11
Engineered extracellular vesicles targeting BACE1 reduces amyloid beta plaque formation in a genetic mouse model of Alzheimer Disease

Kalluri, V. S.; Che, S.; Conner, M.; Moreno Diaz, B.; Yarlagadda, A.; Church, K. A.; Chronopoulos, A.; Vazquez-Arreguin, K.; Sugimoto, H.; Kalluri, R.

2026-08-11 cell biology 10.64898/2026.08.10.744066 medRxiv
Top 0.2%
1.2%
Show abstract

Alzheimers disease (AD) is a progressive neurodegenerative disorder characterized by the accumulation of amyloid-{beta} (A{beta}) plaques, neurodegeneration, and cognitive decline. {beta}-Site amyloid precursor protein cleaving enzyme 1 (BACE1) catalyzes the rate-limiting step in A{beta} production and remains a therapeutic target for AD. However, effective delivery of RNA therapeutics to the brain remains challenging due to the blood-brain barrier (BBB). Here, we evaluated the feasibility of using clinical-grade mesenchymal stem cell-derived extracellular vesicles (EVs) as systemic carriers for Bace1-targeting small interfering RNA (siRNA) in the 5xFAD mouse model of AD. Engineered EVs crossed the BBB and delivered siRNA cargo to the brain, with uptake observed in both neurons and astrocytes. Systemic therapy with EVs engineered to encapsulate Bace1 siRNA resulted in reduced brain Bace1 protein levels and a decrease in amyloid plaque burden compared with control EVs carrying scrambled siRNA. The reduction was most pronounced in larger, high-intensity plaques, suggesting that Bace1 suppression may preferentially limit plaque growth and maturation. Repeated systemic administration was well tolerated, with no evidence of treatment-associated toxicity. These findings establish a proof-of-concept feasibility for EV-mediated delivery of Bace1-targeting siRNA to the brain and support further development of engineered EVs as a therapeutic platform for neurodegenerative diseases. Future studies incorporating behavioral, molecular, and mechanistic analyses will be required to determine the extent to which Bace1 suppression delivered through EVs can modify disease progression and improve functional outcomes in AD.

12
Surface Functionality and pH Govern Structural Dynamics and Drug Binding in PETIM and PAMAM Dendrimers

Garg, A.; Mogurampelly, S.; Kanchi, S.

2026-08-07 biophysics 10.64898/2026.08.04.742721 medRxiv
Top 0.2%
1.1%
Show abstract

1.Surface functionality and pH play a decisive role in governing the structural dynamics, hydration, and drug-binding behaviour of dendrimers. Here, all-atom molecular dynamics (MD) simulations were performed on five generations of PAMAM (G1-G5) and PETIM (G2-G6) dendrimers with O-core and N-core architectures, functionalized with amine, carboxylic acid, or sugar terminal groups under different protonation states. Protonation of the tertiary branch-point amines expands the dendrimer structure, increases internal porosity and hydration, and enhances structural fluctuations across both families. In contrast, non-protonated amine -NH2 (NP) and carboxylic acid -COOH (NP) terminated dendrimers, together with deprotonated carboxylate-COO- (DeP) systems, retain comparatively compact conformations. Sugar-functionalized dendrimers ({beta}-galactose-terminated PETIM and D-glucose-terminated PAMAM) are most hydrated and structurally rigid, whereas amine-terminated dendrimers exhibit the greatest conformational dynamics. PAMAM dendrimers with -NH2, -NH3+, and -COO- terminal groups are generally more hydrated than their PETIM counterparts. However, {beta}-galactose-terminated PETIM dendrimers are more hydrophilic than D-glucose-terminated PAMAM dendrimers. N-core PETIM dendrimers also adopt more compact and spherical conformations than equivalent O-core PETIM dendrimers. Drug-binding MD simulations show that curcumin binding is dominated by van der Waals (vdW) interactions, whereas doxorubicin complexation is primarily driven by electrostatic interactions. Among the investigated surface functionalities, -NH2 (NP), -NH3+ (P), -COOH (NP), and -COO- (DeP) terminations exhibit the most favourable drug-binding characteristics. Except for deprotonated carboxylate systems, curcumin binds more strongly than doxorubicin. Overall, these findings establish molecular-level relationships between surface functionality, protonation state, dendrimer architecture, and drug-binding behaviour, providing design principles for pH-responsive dendrimer nanocarriers with enhanced drug-loading and controlled-release performance. TOC O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=75 SRC="FIGDIR/small/742721v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@119bf29org.highwire.dtl.DTLVardef@1554d86org.highwire.dtl.DTLVardef@154a254org.highwire.dtl.DTLVardef@16d5c5b_HPS_FORMAT_FIGEXP M_FIG C_FIG

13
Regucalcin-containing extracellular vesicles suppress M2 macrophage polarization and attenuate tumor progression in vivo

Okada, R.; Tominaga, K.; Yamamoto, T.; Yamaguchi, M.; Tominaga, N.

2026-08-11 cancer biology 10.64898/2026.08.09.743746 medRxiv
Top 0.2%
1.0%
Show abstract

Regucalcin (RGN) plays diverse roles in cell biology, highlighting its importance in both physiological and pathological conditions. Prostate cancer patients with higher RGN expression exhibited significantly longer disease-free survival. Although RGN is a cell signaling suppressor, the molecular mechanisms underlying tumor suppression by RGN in the tumor microenvironment through cell-cell communication remain unclear. PC3 prostate cancer cell lines stably expressing RGN or a control vector were generated for this study. Extracellular vesicles (EVs) were isolated from these cell lines using differential ultracentrifugation. The murine macrophage cell line J7441 was treated with isolated EVs, and effects on M2 polarization were evaluated using qRT-PCR and western blot analysis. To assess the potential anti-tumor effects of EVs, PC3 parental cells were subcutaneously implanted at two sites per mouse, followed by intratumoral injection of the respective EVs. Tumor volume was monitored. Harvested fresh frozen tumor tissues underwent immunofluorescence staining for CD206, an M2 macrophage marker. RGN was detected in EVs from RGN-expressing cells, and treatment with these RGN-containing EVs was associated with reduced tumor growth and reduced M2 macrophage polarization in vitro and in vivo. Furthermore, recombinant RGN protein reduced the levels of p-AKT1 and p-ERK1/2. Moreover, the suppression of M2 macrophage polarization by RGN-containing EVs was accompanied by decreased p-AKT1 and p-ERK1/2 in vitro. This study describes an EV-associated mechanism that may contribute to the regulation of macrophage polarization and indicates that RGN-containing EVs merit further evaluation as a candidate approach for cancer treatment. Causal validation, such as macrophage depletion or CD206 knockdown, and evaluation in additional models remain to be addressed in future studies.

14
Optimizing 3D Spheroid Formation in Microwells via a Simple Pluronic F127 Coating

Ho, N.; Kato, H.; Komatsu, H.

2026-08-19 bioengineering 10.64898/2026.08.18.744263 medRxiv
Top 0.3%
1.0%
Show abstract

Three-dimensional (3D) spheroid culture provides a physiologically relevant alternative to conventional two-dimensional culture, but reliable spheroid formation in microwells depends on limiting cell-substrate adhesion. Pluronic F127 is an amphiphilic triblock copolymer that forms a hydrated surface layer, reducing protein adsorption. Here, we evaluated whether this intrinsic anti-fouling property could restore an anti-adhesive surface in used microwell plates to promote spheroid formation. Using chondrogenic ATDC5 and pancreatic {beta}-cell INS-1 cells, we characterized spheroid assembly kinetics, F127 cytotoxicity, surface hydrophilicity, protein adsorption, and spheroid morphology including size and shape factor. Both cell types formed compact spheroids within 24 hours on commercial anti-adhesive microwells. F127 coating markedly reduced water contact angle and protein adsorption, confirming increased surface hydrophilicity and reduced protein fouling. In microwells stripped of their original surface coating, F127 coating amounts of approximately 0.011-0.045 mg/cm2 consistently promoted spheroid formation across both cell types. Soluble F127 concentrations were confirmed to be non-cytotoxic up to 0.625% (w/v), while even complete dissolution of the highest tested coating amount would correspond to only 0.025% (w/v) F127. This simple, reproducible, and low-cost surface-modification strategy may provide an accessible approach for re-functionalizing microwell platforms for 3D cell culture.

15
Multi-omics characterization of extracellular vesicles derived from virus-positive Merkel cell carcinoma cells

Westerkamp, U. A.; Blümke, P.; Salviano-Silva, A.; Schmidt, C.; Mair, T.; Siebels, B.; Huang, J.; Fischer, N.

2026-08-19 molecular biology 10.64898/2026.08.15.745013 medRxiv
Top 0.3%
0.9%
Show abstract

Merkel cell carcinoma (MCC) is a highly aggressive skin cancer, with approximately 80% of cases driven by Merkel cell polyomavirus (MCPyV). Although extracellular vesicles (EVs) are increasingly recognized as mediators of intercellular communication within the tumor microenvironment, their molecular cargo in MCPyV-positive MCC has not been comprehensively characterized. Here, we performed a multi-omics characterization of EVs released by two MCPyV-positive MCC cell lines. EVs were isolated by differential ultracentrifugation and characterized by nanoparticle tracking analysis, imaging flow cytometry, cryo-electron microscopy, and immunoblotting, demonstrating a heterogeneous population of small and large EVs. Proteomic and transcriptomic analyses revealed that MCC-derived EVs possess distinct protein, mRNA, and miRNA cargo compared with their parental cells, with enrichment of molecules associated with gene expression, RNA processing, intracellular signaling, and vesicle-mediated transport. Despite differences in the molecular composition of EVs derived from WaGa and MKL-1 cells, functional enrichment analyses revealed highly similar biological pathways. To investigate whether the viral oncoprotein small T antigen (sT) contributes to EV cargo composition, EVs from inducible sT knockdown cells were analyzed. Loss of sT was associated with modest changes in the EV proteome and mRNA cargo, whereas the overall EV-associated miRNA profile remained largely unchanged. Collectively, these findings provide the first comprehensive molecular characterization of EVs released by MCPyV-positive MCC cells and establish a foundation for investigating the contribution of EV-mediated communication to MCC biology and tumor-microenvironment interactions.

16
Immunomodulatory mechanisms of submicron phosphatidylserine-exposing polymeric particles (PSPs)

Clarin, M. T. R. D. C.; Kimura, K.; Nabil, A.; Uto, K.; Motoyama, E.; Aung, H. H. H.; Ebara, M.; Yanagisawa, H.

2026-08-10 bioengineering 10.64898/2026.08.07.743390 medRxiv
Top 0.3%
0.8%
Show abstract

Macrophages are highly dynamic cells that maintain tissue homeostasis by regulating both initiation and resolution of inflammation. During efferocytosis, macrophages recognize the eat me signal, phosphatidylserine (PS), exposed at the surface of apoptotic cells, leading to the resolution of inflammation and acquisition of a pro-resolving phenotype. Inspired by this endogenous mechanism, PS-based biomaterials have demonstrated immunomodulatory potential. However, the molecular mechanisms underlying PS-mediated macrophage reprogramming remain poorly understood. Here, submicron PS-exposing polymeric particles (PSPs; [~]300 nm) were developed to improve the suitability of PSP formulations for future systemic administration while preserving their immunomodulatory activity. PSPs were efficiently internalized by macrophages through both actin- and dynamin-dependent pathways. PSP treatment significantly reduced IL-6 and IL-12p70 production in LPS-stimulated macrophages, whereas induction of the classical anti-inflammatory M2 marker CD206 was limited. Transcriptomic analysis revealed coordinated attenuation of inflammatory signaling pathways, including downregulation of Myd88, Nfkb1, Rel, and Irf8, together with activation of NRF2-associated antioxidant pathways characterized by increased expression of Nfe2l2, Hmox1, Prdx1, Gclm, and Gclc. Activation of antioxidant-associated genes together with reduced Irf8 expression suggests that PSP promotes inflammatory resolution through coordinated redox adaptation and selective attenuation of inflammatory signaling. Collectively, these findings provide mechanistic insight into PS-mediated macrophage reprogramming and support the future development of systemically administered therapies for chronic inflammatory diseases, including vascular inflammatory disorders. HighlightsO_LISubmicron PSPs retain immunomodulatory activity of apoptotic cell-mimicking biomaterials. C_LIO_LIPSPs are rapidly internalized through actin- and dynamin-dependent pathways. C_LIO_LIPSPs attenuate inflammatory signaling and selectively suppress IL-6 and IL-12p70 production. C_LIO_LIPSPs induce NRF2-associated antioxidant and glutathione responses. C_LIO_LITranscriptomics reveals an early redox-adaptive macrophage program. C_LI

17
Systemic Nanobubbles Enable Ultrasound-Guided STING Immunotherapy in Breast Cancer

Hafeez, N.; Khorsandi, S.; Gao, R.; Khalid, A.; Ali, S.; Movaghar, T.; Garland, S.; de Gracia Lux, C.; Lux, J.

2026-08-19 bioengineering 10.64898/2026.08.13.744654 medRxiv
Top 0.3%
0.8%
Show abstract

Activation of the STING pathway can induce potent antitumor immunity, but effective delivery of STING agonists to the tumor while limiting systemic exposure remains challenging. We previously developed MUSIC, an ultrasound-guided platform that uses microbubbles (MBs) to deliver the STING agonist 2'3'-cGAMP and locally activate antitumor immunity. However, the vascular confinement of MBs and the need for intratumoral administration limit the potential for systemic tumor targeting. To overcome these limitations, we developed SONATA (Systemic Oncotherapy using Nanobubbles for Acoustically-guided Tumor Activation), which employs nanobubbles (NBs) that are approximately 10-fold smaller than conventional MBs, enabling systemic administration and tumor extravasation. Following NB accumulation within tumors, ultrasound exposure triggers localized cGAMP release, facilitating delivery to targeted CD11b+ antigen-presenting cells (APCs) and STING activation with spatial and temporal control. NBs are composed of the same components as MBs, including phospholipid shells and a perfluorobutane core and are functionalized with anti-CD11b antibodies to target CD11b+ APCs and spermine-modified dextran to stably load cGAMP through nanocomplex formation. Upon ultrasound activation, SONATA induced phosphorylation of STING, TBK1, and IRF3 and increased IFN-{beta} production in bone marrow-derived macrophages. In an orthotopic breast cancer model, intravenously administered SONATA combined with tumor-localized ultrasound significantly inhibited tumor growth compared with controls. Furthermore, SONATA synergized with immune checkpoint blockade prolonged the median survival of tumor-bearing mice. Collectively, these findings establish SONATA as a systemically administered immunotherapy platform that enables ultrasound-guided, spatially controlled STING activation.

18
Tail length of triazine-based lipids influences blood clotting risk in vitro and in vivo

Ibnat, N.; Masud, A. A.; Mory, J.; Funk, T.; Mahmood, D. F.; Wood, J.; Venditto, V. J.

2026-08-26 bioengineering 10.64898/2026.08.25.747137 medRxiv
Top 0.3%
0.6%
Show abstract

Lung-targeted delivery of mRNA with lipid nanoparticles (LNPs) demonstrates high potential for therapeutic applications in pulmonary disorders. However, progress in pulmonary mRNA therapeutics is constrained by the challenges of engineering lipids that are both safe and highly effective at targeting the lungs. To meet these critical needs, we designed triazine-based (TZ) ionizable lipids with cyanuric chloride as the linker between the cationic head and the lipophilic tail, which allows for easy derivatization capable of systemic mRNA delivery. Three TZ-based lipids were synthesized using the same ionizable headgroups while differing in the carbon tail length and evaluated for their in vitro and in vivo protein expression. Notably, all three lipids result in pulmonary expression after intravenous administration, but the TZ lipid containing a C14 tail does so without any indication of thrombosis, both in vitro and in vivo as compared to other formulations. Our findings highlight the effect of minor chemical modifications driving altered in vivo activity, thus enabling new opportunities for safe pulmonary delivery of mRNA for lung-related diseases.

19
Cell-Based Sensor for Extracellular DNA

Xia, B.; Kalogriopoulos, N. A.; Wen, R.; Lane, Z. M.; Li, H.; Buitrago, N.; Lee, S.; Gao, R. D.; Ive, I.; Kim, Y.; Ting, A. Y.; Szablowski, J. O.

2026-08-20 synthetic biology 10.64898/2026.08.19.745795 medRxiv
Top 0.4%
0.6%
Show abstract

Detection of molecules with cell-based sensors allows for conversion of binding events into gene expression outputs. Here, we present a cell-based sensor that can detect extracellular double-stranded DNA. This sensor is based on an engineered receptor which we call Luminescent Ultrasensitive Nucleic Acid Reporter, or LUNAR. LUNAR is based on a recently developed Programmable Antigen-gated G-protein-coupled Engineered Receptor (PAGER). PAGERs are a genetic fusion of an auto-inhibitory peptide, a protein-binding domain, and a modified kappa opioid receptor. PAGERs are gated by two binding events. First, a protein ligand displaces an intramolecular inhibitor, Arodyn, then a second ligand activates the receptor. By replacing the protein-binding domain with a DNA binding zinc finger protein (ZFP) we could detect extracellular DNA in a dose-dependent fashion. Here, we show that first-generation LUNAR constructs can detect both oligonucleotides and plasmid double-stranded DNA with nanomolar sensitivity in mammalian cells. Future work will focus on improving sensitivity, fold-change, and multiplexing capabilities for sequence-specific DNA detection.

20
Modelling mechanisms and treatment of cholangiopathies with a bile duct on a chip

Hoyle, H. W.; Frank, A. K.; Amundsen-Isaksen, E.; Peisl, S.; Hovland, O. O.; Yeoh, J.; Selvarajah, M.; Aizenshtadt, A.; Hirayama-Shoji, K.; Sampaziotis, F.; Karlsen, T. H.; Busek, M.; Krauss, S.; Melum, E.

2026-08-20 cell biology 10.64898/2026.08.19.745387 medRxiv
Top 0.4%
0.5%
Show abstract

Background and aims Model systems for bile duct disorders are needed for testing therapeutic interventions. Current models have poor human relevance or limited potential for recreating the complex bile duct microenvironment at scale. We aimed to generate a humanized microphysiological system to model and treat cholangiopathies. Methods An in vitro bile duct was created using 3D printed microfluidic chips containing a collagen-embedded canal seeded with patient-derived primary human cholangiocytes. Barrier permeability and compound transport across the epithelium was measured, and disruption of the barrier was performed with lipopolysaccharide treatment. The duct was challenged with the known hepatotoxicant Chlorpromazine. Biliatresone was used to model biliary-atresia and treated using N-acetyl-L-cysteine. Results Cholangiocytes in the bile duct chip established a tight, polarized epithelial barrier. Verapamil and Linerixibat inhibited transport of rhodamine 123 and cholyl-lys-fluorescein respectively with 66 % (p = 0.0004) and 57 % (p = 0.03) reduction. 10 g/mL lipopolysaccharide led to a loss of epithelial barrier integrity, measured by an increase of over 1000 % in leakage of both 3 kDa (p = 0.0002) and 10 kDa dextran (p = 0.0001) along with upregulation of cytokines. Chlorpromazine displayed dose-dependent toxicity with EC50 values of 84, 140 and 96 M for three patient lines. Biliatresone induced a dose-dependent abnormal phenotype with loss of viability. The induced phenotype could be treated with N-acetyl-L-cysteine, improving viability from 23 % to 59 % (p < 0.0001) with treatment of 2 g/mL Biliatresone. Conclusions Our novel platform allows complex studies of bile duct biology, testing of off-target effects from drugs and treatment of a disease phenotype.