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Bioengineering & Translational Medicine

Wiley

Preprints posted in the last 7 days, ranked by how well they match Bioengineering & Translational Medicine's content profile, based on 21 papers previously published here. The average preprint has a 0.02% match score for this journal, so anything above that is already an above-average fit.

1
Vascularizing neurospheroids to probe vascular contributions to α-synuclein pathology in Parkinson's disease

Alim, A.; Lwin, S.; Saha, P.; Baek, Y.; Lee, M.; Paek, J.

2026-08-31 bioengineering 10.64898/2026.08.28.747883 medRxiv
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Neurodegenerative diseases are increasingly associated with vascular dysfunction beyond progressive neuronal degeneration, yet how vascular pathology contributes to disease progression remains poorly understood, largely due to the lack of a neurodegenerative disease model capable of capturing neuronal pathology alongside associated vascular dysfunction. Here, we developed a microengineered 3D vascularized brain tissue model that integrates neurospheroids with a self-assembled, perfusable vascular network to recapitulate key features of the neurovascular interface. Using this model, we investigated the vascular contribution to Parkinson's disease pathology by introducing -synuclein preformed fibrils into the engineered vasculature. Intravascular -syn fibril exposure induced endothelial barrier disruption, vascular leakage, inflammation, and vascular regression. Notably, this vascular insult was accompanied by intraneuronal -synuclein aggregation within neurospheroids, suggesting that vascular dysfunction may facilitate the exposure of neural tissue to pathogenic -synuclein. Our neurodegenerative disease modeling approach establishes a versatile and tractable platform for investigating vascular contributions to neurodegenerative disease progression.

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A fibril-inducing support-bath enables embedded 3D printing of aligned collagen-rich constructs

Gonnella, G.; Milazzo, R.; Gibney, R.; Kelly, D.

2026-08-31 bioengineering 10.64898/2026.08.30.748057 medRxiv
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Embedded extrusion printing can process collagen-rich bioinks, but their low viscosity and slow fibrillogenesis compromise print fidelity and post-deposition stability. Here, we developed a collagen fibril-inducing support bath (FIB) that combines mechanical support for embedded printing with biochemical induction of collagen assembly. Microfibrillated or nanofibrillated cellulose was incorporated into a fibril-inducing buffer, and formulations were screened at 37 degrees Celsius for rheological behaviour and optical transparency. The selected FIB was evaluated by printing 1% and 5% (w/v) articular cartilage-derived extracellular matrix (ECM) inks at 10-20 mm/s and compared with a cellulose-only control bath. FIB exhibited yield-stress, shear-thinning and rapid recovery behaviour that supported reproducible filament deposition. Unlike the control bath, FIB enabled intact construct retrieval following stabilisation and promoted the formation of fibrillar collagen within the printed strands. Scanning electron microscopy revealed D-banded collagen fibrils preferentially oriented along the deposition direction, with dominant orientation peaks within +/- 10-15 degrees. The platform supported the fabrication of 15 x 15 x 1.5 mm sheets and 6 x 6 x 6 mm scaffolds whose macroscopic dimensions were retained after processing. Constructs produced from 5% ECM inks exhibited approximately fourfold higher ramp and relaxation moduli than those produced from 1% ECM inks. Extracts from both formulations caused no detectable reduction in cell metabolic activity after 24 h or 72 h. Mesenchymal stem/stromal cells (MSCs) seeded onto printed sheets became markedly elongated and aligned by day 3, with approximately 80% of cells having an aspect ratio exceeding 1.5, significantly greater than cells seeded onto casted ECM controls, with a mean deviation of ~9 degrees from the filament print direction. These findings establish FIB as a bioactive support bath that couples embedded printability with collagen fibrillogenesis, enabling recoverable collagen-rich constructs with aligned fibrillar architecture that directs early cellular organisation.

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Extracellular matrix composition is associated with tissue-specific decellularization susceptibility and mechanical remodeling across human urogenital tissues

Bolduc, S.; Chabaud, S.; Droit, A.; Fourcassie, V.; Roux-Dalvai, F.; Sahuc, Y.; Sueters, J. J.

2026-08-31 bioengineering 10.64898/2026.08.28.747607 medRxiv
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Decellularized extracellular matrices (ECMs) are widely used in regenerative medicine, yet current evaluation criteria prioritize cellular removal rather than preservation of the ECM characteristics that govern tissue behavior. Here, we demonstrate that efficient decellularization is achieved across a broad range of chemical conditions, whereas preservation of structurally and biologically relevant ECM components is confined to narrow, tissue-specific windows defined by coupled detergent interactions. Quantitative proteomics revealed that intrinsic ECM composition is strongly associated with tissue-specific susceptibility to decellularization-induced damage and provided molecular context for the distinct preservation responses between tissues. Optimized matrices retained major structural ECM components and supported tissue-specific cellular organization and cell-mediated mechanical reinforcement following cellular repopulation despite uniformly low residual DNA across protocols. Together, these findings support a shift in decellularization quality assessment from DNA-based evaluation toward preservation of biologically relevant ECM and establish a composition-driven strategy for the rational design of regenerative biomaterials with tissue-relevant biological and mechanical properties.

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Elevated hydrostatic pressure modulates endothelial junctional mechanotransduction through VE-cadherin remodelling and altered association with YAP1, EPS8: an endothelium-on-chip study

Vasanthi Bathrinarayanan, P.; Abadie, T.; Vigolo, D.; Simmons, M. J. H.; Grover, L. M.

2026-09-01 bioengineering 10.64898/2026.08.31.748221 medRxiv
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Endothelial dysfunction is a hallmark of numerous vascular pathologies and is strongly influenced by mechanobiological forces within the vascular microenvironment. While the effects of shear stress have been extensively investigated, the mechanisms by which elevated hydrostatic pressure regulates endothelial junctional organisation remain sparsely investigated. Here, we employed a microfluidic platform to investigate the combined effects of low shear stress (1.4 dyne/cm2) and elevated hydrostatic pressure (~3972 Pa) on endothelial junctional dynamics. Elevated hydrostatic pressure induced marked remodelling of VE-cadherin junctions, characterised by formation of serrated, finger-like structures accompanied by increased YAP1 nuclear localisation and reduced YAP1-VE-cadherin cytoplasmic colocalisation compared to shear stress alone conditions. Further, elevated hydrostatic pressure also demonstrated an increase in cytoplasmic accumulation of EPS8, an actin adaptor protein, and increased cytoplasmic EPS8-VE-cadherin colocalisation. These observations were accompanied by functional changes marked by increased endothelial permeability, and enhanced THP-1 monocyte adhesion, thus suggesting activation of mechanosensitive pathways linked to dynamic junctional reorganisation. Inhibition of PI3K at elevated hydrostatic pressure exhibited a thin VE-cadherin patterning and increased cytoplasmic EPS8-VE-cadherin colocalisation, thus demonstrating a prominent role for PI3K signalling in regulating the junction organisation. Interestingly, Piezo-1 activation using Yoda1 produced context-dependent effects. Under shear stress alone, Yoda1 promoted YAP1 nuclear translocation, reduced YAP1-VE-cadherin colocalisation, increased endothelial permeability but strikingly did not impact THP-1 adhesion compared to shear stress alone conditions. In contrast, under elevated hydrostatic pressure conditions, Yoda1 significantly reduced both endothelial permeability and THP-1 adhesion while increasing YAP1-VE-cadherin colocalisation and decreasing YAP1 nuclear accumulation. Collectively, these findings identify a previously underappreciated elevated hydrostatic pressure-Piezo-1-PI3K signalling axis that regulates endothelial barrier integrity and pro-adhesive endothelial activation through coordinated regulation of VE-cadherin, YAP1, and EPS8. These results highlight elevated hydrostatic pressure as a unique mechanobiological stimulus, distinct from that of shear stress alone and provide novel insights into mechanisms underlying microvascular dysfunction.

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A Tunable Flat-Jet Hydro-Debridement Device: Clinical Feasibility for Soft Tissue Wound Management

DATTA, A.; Majumder, R.; Biswas, I.; Ganguly, R.; Santra, A. K.; Sarkar, S.; Gumta, M. K.; Sarkar, S.

2026-09-04 surgery 10.64898/2026.09.01.26361120 medRxiv
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Background: Chronic wounds, ulcers, and lacerations require staged debridement and irrigation to promote healing. However, conventional techniques of debridement, such as surgical, chemical, or autolytic, struggle to fully remove residual necrotic tissue, slough, and unhealthy granulation from wound sites, especially when lodged within wound clefts and cavities, and in wounds with exposed structures. This promotes polymicrobial biofilms, delays wound closure, and causes significant discomfort with increased morbidity. Objective: To demonstrate the feasibility of using an indigenously developed tunable flat-jet hydro-debridement device (presently termed as CleanseJet), a frugal wound debridement system designed for deployment in resource-constrained clinical settings. Methods: An open-label, interventional, single-centre, parallel-group pilot randomized controlled trial was conducted to clinically evaluate an indigenously developed tunable flat-jet hydro-debridement device in patients with wounds of varied aetiology. The device provided adjustable spray impact force and coverage area tailored to wound characteristics. Outcomes were compared with a control group receiving standard wound care alone, with time to complete granulation serving as the primary healing endpoint. Outcomes were compared with a control cohort receiving standard of care alone. Results: The removal of loose devitalized tissue, slough, and biofilms from the wound bed improved the healing, which were monitored using the SINBAD scoring system. No adverse events were reported, supporting the feasibility and safety of CleanseJet. Conclusion: While commercial hydro-debridement systems are effective, they are often costly, rely on disposable components, and require specialized training. In contrast, CleanseJet provides a low-cost, easy-to-use alternative that can be operated with minimal training, making it suitable for broader clinical use without observed adverse effects.

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Development and Optimization of 111In-Dinutuximab-IRDye800, a Dual-Modality Intraoperative Molecular Imaging Agent for Pediatric Neuroblastoma Resection

Yip, C. Y.; Rosenblum, L. T.; Pant, A.; Kahler-Quesada, A.; Chagantipati, B.; Sever, R.; Grano-Mickelsen, B.; Li, B.; Cortez, A. G.; Latoche, J. D.; Day, K. E.; Rigatti, L.; Nedrow, J. R.; Edwards, B. W.; Kohanbash, G.; Malek, M. M.

2026-08-31 cancer biology 10.64898/2026.08.28.747876 medRxiv
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Rationale: Neuroblastoma is a devastating pediatric malignancy, for which surgical resection is a key factor in long-term survival. However, there are significant challenges in its resection, particularly in high-risk disease, as neuroblastoma encases surrounding critical structures, is often difficult to distinguish from desmoplastic or scar tissue, and can carry occult deposits of disease not readily identified on preoperative imaging or intraoperative visualization. Building on the principles of fluorescent and radio-guided surgery, in combination with the known overexpression of GD2 in neuroblastoma, we sought to develop and optimize 111In-Dinutuximab-IRDye800, a dual-modality GD2-targeted intraoperative molecular imaging agent, for use in pediatric neuroblastoma to help enhance patient safety while facilitating a more complete resection. Methods: Dinutuximab was conjugated to IRDye800 and DTPA, then radiolabeled with Indium-111 to yield 111In-Dinutuximab-IRDye800. Optimization occurred through ELISA assay to assess binding affinity, fluorescence intensity analysis to determine the optimal fluorescent degree of labeling, and phototoxicity testing through flow cytometry. Rodent models of neuroblastoma were then generated through injection of SK-N-BE(2) human neuroblastoma cells into the left adrenal glands of nude mice or RNU rats. A series of fluorescent and gamma biodistributions was performed, varying the dose, timing, and specific activity of the tracer. Tumor and organ uptake of the tracer was compared with one- or two-way ANOVA as appropriate, with Sidaks multiple comparison test to compare tumor uptake to individual organs. Once optimization was complete, a clinically significant events study modeled after human clinical trials was performed to evaluate the in vivo capabilities of 111In-Dinutuximab-IRDye800. Results: Increased ratios of IRDye800 per antibody led to decreased binding affinity for GD2 and was associated with formulation instability without significant return on fluorescence intensity. Specific activity of the tracer was not found to impact overall biodistribution of the tracer. A 45-50 microgram dose of 111In-Dinutuximab-IRDye800 with ratios around 1 DTPA and 1-1.5 IRDye800 per antibody imaged 4 days after tracer administration was found to be the optimal combination that maximized detectable tumor-specific signal. In the clinically significant events study mirroring human IMI clinical trials, fluorescent guidance identified additional malignant lesions not originally detected under white light in 64% of rodents. Conclusions: 111In-Dinutuximab-IRDye800 is a dual-modality GD2-targeted intraoperative imaging agent that is well-poised for clinical translation. As it preserves tumor specificity, yields clinically meaningful radiofluorescent signal, and is well-tolerated without adverse events after optimization was completed, it carries the potential to positively impact the safety and completeness of neuroblastoma resection.

7
Multilayered extracellular matrix derived scaffolds direct progenitor cell differentiation in vitro and osteochondral-tissue formation in vivo.

Gonnella, G.; Strong, O.; Sularea, V. M.; Soares Kronemberger, G.; Karam, A. S.; Kelly, D.

2026-08-31 bioengineering 10.64898/2026.08.28.747815 medRxiv
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Osteochondral repair requires restoration of zonally organised articular cartilage and subchondral bone, yet translatable implants rarely reproduce this spatial complexity. Here, we developed an off-the-shelf, cell-free multilayer scaffold comprising a superficial 2% (w/v) articular cartilage extracellular matrix (AC-ECM) phase, an intermediate 5% AC-ECM phase and a basal 6% bone ECM (BN-ECM) phase. The scaffold formed continuous interfaces, displayed regionally distinct pore sizes and resisted permanent deformation during cyclic compression. In vitro, constructs seeded with caprine mesenchymal stromal and articular cartilage progenitor cells supported cell expansion and the accumulation of sulfated glycosaminoglycan- and collagen-rich matrix, with regional differences in collagen I, II and X deposition. Following eight weeks of subcutaneous implantation, cell-seeded scaffolds contained more collagenous matrix than unseeded controls, while vascularisation preferentially localised to the BN-ECM phase. The scaffold was then evaluated against empty defects in a caprine osteochondral model for six months. Scaffold treatment significantly improved macroscopic and histological repair, increased chondral tissue fill (~60% versus ~40%), limited cartilage-like tissue extension into the subchondral region and generated a more native-like superficial collagen organisation. Repair tissue further exhibited greater collagen II immunoreactivity, increased ACAN and COL2A1 expression and reduced COL1A2 expression relative to empty defects, although deeper bone repair was not significantly improved. These findings demonstrate that tissue-specific ECM layering can spatially guide endogenous repair and substantially improve cartilage restoration without exogenous cells or growth factors in a clinically relevant large-animal model, while identifying subchondral bone regeneration as the remaining design challenge for complete osteochondral repair.

8
Antibody co-administration robustly improves proton therapy with radiosensitizing nanoparticles: a mathematical modeling study

Kuznetsov, M.; Kolobov, A.

2026-09-01 cancer biology 10.64898/2026.08.30.748121 medRxiv
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Radiosensitizing nanoparticles represent a promising approach for enhancing the efficacy of proton radiotherapy; however, their performance is constrained by restricted penetration into tumor tissue, resulting in preferential perivascular accumulation. Here, we develop a spatially distributed mathematical model of a growing tumor undergoing proton therapy with intravenously administered radiosensitizing nanoparticles to investigate treatment optimization strategies. Using physiologically plausible parameter ranges informed by our own experimental measurements and published data, we demonstrate that co-administration of targeted nanoparticles with antibodies binding to the same tumor receptors can overcome transport-induced localization and promote a more uniform intratumoral redistribution of nanoparticles before irradiation. Population-level simulations across heterogeneous parameter sets suggest that moderate antibody doses consistently prolong tumor regrowth time, whereas higher antibody doses produce a pronounced and robust increase in tumor cure probability under a single high-dose irradiation regimen representative of preclinical settings. A key conceptual result of our analysis is the asymmetric risk associated with antibody co-administration. In contrast to antibody--drug conjugates, for which excessive dosing of unconjugated antibodies may severely compromise therapeutic efficacy, co-administration of antibodies with nanoparticle-based radiosensitizers constitutes a "safe-by-design" strategy with respect to tumor cell kill in the modeled single high-dose irradiation setting: although excessive antibody doses may yield suboptimal outcomes, they cannot reduce tumor cell kill below that achieved with targeted nanoparticles administered without antibodies. These findings identify antibody-mediated spatial redistribution of radiosensitizing nanoparticles as a favorable strategy that is expected to provide robust therapeutic benefit despite substantial variability in tumor characteristics.

9
Burden of fatigue in compensated chronic liver disease: findings from the multinational a:GAP Study

Choudhuri, G.; Akhundova-Unadkat, G.; Naidoo, N.; Morales-Castillo, M.; Guillaume, X.; Duijnhoven, R. G.; Safaei, A.; Swain, M. G.

2026-09-02 gastroenterology 10.64898/2026.08.28.26361618 medRxiv
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Background & Aims: Fatigue is a central symptom of chronic liver disease (CLD), substantially impacting health-related quality of life (HRQoL). This study aimed to further understand CLD symptomatology, including fatigue, and its impact on HRQoL from a patient perspective. Methods: Abbott Global Assessment of Patients unmet needs (aGAP) was a multinational, cross-sectional survey in adults with compensated CLD in China, India and Mexico, conducted between July and November 2024. Adult participants who self-reported that they had physician-diagnosed CLD and were experiencing fatigue completed a quantitative survey to assess symptom burden and included three HRQoL patient-reported outcome (PRO) questionnaires (Patient-Reported Outcomes Measurement Information System [PROMIS]-29+2, Work Productivity and Activity Impairment - Specific Health Problem version 2.0 [WPAI: SHP], Multidimensional Fatigue Inventory [MFI]). Results: Overall, 505 participants (China: 200; Mexico: 105; India: 200) completed the study. Participants reported that their CLD-related fatigue sometimes, often or always affected their self-esteem/confidence (45.1%) and ability to maintain or acquire new employment (38.6%). Most participants reported moderate (51.3%) or serious (26.9%) fatigue, with 33.5% experiencing fatigue every day or almost every day. Many participants felt their social life was negatively impacted by their fatigue (47.3%) and that there were related financial difficulties (53.9%). Use of validated PRO tools demonstrated severe fatigue (MFI: overall mean [SD] 13.9 [3.4] general fatigue and 13.4 [3.6] physical fatigue) as well as substantial levels of work and activity impairment (WPAI: SHP overall mean [SD] 53.0 [26.4]) and high levels of anxiety, pain interference, depression and sleep interference (PROMIS T-scores [≥]54). Conclusions: Fatigue has a substantial impact on HRQoL among adults with CLD across several countries, highlighting a global unmet need for targeted interventions to effectively identify and manage the condition.

10
3D ultrasound fascicle tractography for objective muscle architecture analysis.

Tecchio, P.; Schlaffke, L.; Bolsterlee, B.; Hahn, D.; Raiteri, B. J.

2026-09-01 bioengineering 10.64898/2026.08.31.746736 medRxiv
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Muscle architecture shapes muscle function and changes with age, growth, training and disease, yet quantifying three-dimensional (3D) muscle architecture in vivo remains challenging. We introduce a hybrid fascicle tractography approach for freehand 3D ultrasound data that accurately reconstructs 3D muscle fascicles with respect to an objective, anatomically relevant coordinate system defined by the muscle's central aponeurosis. The hybrid approach combines Hessian-based fascicle detection with wavelet-based refinement to generate volumetric fascicle orientations. In a synthetic dataset with known ground truth, fascicle orientations and lengths were estimated with errors of [≤]2{degrees} and ~1.5%, respectively. In vivo, the approach detected physiologically plausible fascicle lengthening in the human tibialis anterior following a passive plantar flexion rotation, whereas diffusion tensor imaging of the same muscle did not. The proposed method enables anatomically relevant, objective and non-invasive quantification of 3D muscle architecture in vivo, providing a practical framework for applications in clinical and applied muscle physiology.

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Influence of trunk posture on spinal loading and paraspinal muscle forces in adolescent idiopathic scoliosis: a subject-specific musculoskeletal modelling study

Bhattacharya, R.; Garg, B.; Malhotra, R.; Ghosh, R.; Chawla, A.; Mukherjee, K.

2026-09-01 bioengineering 10.64898/2026.08.28.747718 medRxiv
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Adolescent idiopathic scoliosis (AIS) alters spinal geometry and may influence the biomechanical response of the spine during functional postures. However, posture-dependent changes in spinal loading and paraspinal muscle forces in AIS remain poorly understood. This study investigated the effects of trunk posture on intervertebral loading and paraspinal muscle forces using a subject-specific musculoskeletal model of an adolescent with AIS. The spinal deformity was reconstructed from biplanar radiographs and incorporated into a full-body musculoskeletal model. Flexion, extension, lateral bending, and axial rotation were simulated at three incremental magnitudes, with motion distributed across the thoracolumbar spine. Intervertebral compressive and lateral forces around the curve apex and forces in the erector spinae (ES) and multifidus (MF) muscles were evaluated. Trunk flexion produced the greatest compressive loading, reaching 337 N at the curve apex and 372 N two levels below the apex at 30{degrees} flexion. Lateral bending produced pronounced direction-dependent loading: concave-side bending increased lateral forces, whereas convex-side bending increased compressive forces. Axial rotation produced similar but smaller direction-dependent changes. Paraspinal muscle forces were consistently asymmetric, with concave-side dominance of the ES and convex-side dominance of the MF. Flexion and convex-sided movements generally produced greater muscle imbalance, while increasing posture magnitude amplified spinal loading and muscle forces. These findings demonstrate that trunk posture, movement direction, and magnitude substantially influence the biomechanical environment of the scoliotic spine and should be considered when evaluating spinal mechanics in AIS.

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Near-infrared optoacoustic modulation of the blood-brain barrier permeability using size-tuned hyperbranched gold nanoconstructs

Wu, Y.; Ge, Y.; Li, X.; Sun, H.; Zhang, Y.; Li, C.; Chen, G.; Jiang, J.

2026-09-01 bioengineering 10.64898/2026.08.30.748173 medRxiv
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The blood-brain barrier (BBB) constitutes a major bottleneck for the systemic delivery of most therapeutic agents to the central nervous system. Here, we report near-infrared reversible optoacoustic modulation of the BBB permeability (NIR-ROAMBBB), leveraging endothelial tight junction targeting hyperbranched gold nanoconstructs (HBGNCs) to amplify localized optoacoustic transduction under femtosecond laser excitation. We first synthesized HBGNCs with tunable particle sizes (62-150 nm) and consistent branch morphologies via a seed-mediated growth approach, and uncovered a non-monotonic relationship between particle dimension and optoacoustic output, where the 62 nm HBGNCs generated nearly twofold stronger optoacoustic signal than gold nanorods and gold nanostars under matched excitations. Conjugation with BV11 antibodies against junctional adhesion molecule A increased HBGNC endothelial association and cerebral accumulation, enabling focal and fluence-dependent transient BBB opening (3-6 h) under 800 nm femtosecond pulsed laser excitation, as validated by in vitro trans-endothelial electrical resistance measurements, ex vivo Evans blue extravasation staining, and in vivo NIR imaging. Featuring deep tissue penetration of NIR light, robust optoacoustic conversion of HBGNCs, and negligible femtosecond laser-induced photothermal damage, this non-invasive strategy enables precise focal modulation of BBB permeability and potential drug delivery.

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Development and pharmacological evaluation of an intranasal liposomal norbinaltorphimine formulation for the prevention of pain-induced negative affect

Lorente, J. D.; Campos-Jurado, Y.; Martinez-Navarrete, M.; Cuitavi, J.; Cervera-Sospedra, M.; Higginbotham, J. A.; Melero, A.; Polache, A.; Guillot, A. J.; Moron, J.; Hipolito, L.

2026-09-01 neuroscience 10.64898/2026.08.26.747378 medRxiv
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Chronic pain is frequently accompanied by negative affect and motivational deficits due to dysregulated mesocorticolimbic dopamine and kappa opioid receptor (KOR) signalling. Although intracranial KOR antagonism prevents pain-induced negative affect in preclinical models, systemic KOR antagonists can produce adverse off-target effects in the periphery, thereby limiting its clinical utility. Consistent with this, we found that systemic administration of KOR antagonist norbinaltorphimine (NorBNI), exacerbated motivational deficits in rats with persistent inflammatory pain. We hypothesized that maximizing central and minimizing peripheral KOR antagonism could overcome these limitations. To test this, we engineered an intranasal liposomal NorBNI formulation incorporated into an in-situ forming mucoadhesive hydrogel to enable selective nose-to-brain delivery (Nor-BNILV-HG). We characterized its physicochemical properties and functional efficacy in rats with inflammatory pain produced by Complete Freund's Adjuvant (CFA). NorBNI-loaded liposomes exhibited high drug entrapment efficiency, nanometric size, and suitable surface charge for intranasal administration. The selected thermosensitive hydrogel demonstrated appropriate gelation properties and sustained drug release. Intranasal administration of NorBNI-LV-HG produced negligible systemic NorBNI levels compared with intraperitoneal delivery. In vivo microdialysis showed that NorBNI-LV-HG prevented KOR agonist-induced reductions in nucleus accumbens (NAc) dopamine release, confirming functional central KOR blockade. Behaviourally, intranasal NorBNI-LV-HG attenuated pain-induced impairments in sucrose motivation. Importantly, unlike systemic NorBNI, repeated intranasal NorBNI-LV-HG did not alter mechanical nociceptive thresholds in pain-naive animals, suggesting this strategy mitigates unwanted peripheral nociceptive effects. Together, these findings demonstrate that intranasal NorBNI-LV-HG achieves functional brain KOR antagonism while minimizing systemic exposure and off-target effects. Selective nose-to-brain delivery of KOR antagonists therefore represents a promising therapeutic strategy to prevent and potentially reverse the affective and motivational consequences of pain and may overcome key translational barriers associated with systemic KOR treatments.

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Immortal time bias reproduces the reported survival benefit of conversion surgery in stage IV gastric cancer: a simulation study

Sah, B. K.; Li, C.; Li, J.; Zhu, Z.

2026-09-03 gastroenterology 10.64898/2026.09.01.26361986 medRxiv
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Background Conversion surgery for stage IV gastric cancer is supported by a pooled overall survival hazard ratio of 0.36 (95% confidence interval 0.32-0.40) and, in the largest international cohort, median survival of 36.7 versus 12.5-13.8 months on chemotherapy. Survival is measured from diagnosis; the median diagnosis-to-gastrectomy interval is 124 days, which patients must survive to be counted surgical. Methods We simulated cohorts of 3,177 stage IV gastric cancer patients from published parameters: background median survival 14.5 months; median diagnosis-to-surgery interval 124 days (category-specific 92-174 days). Surgery had no effect (true hazard ratio 1.00 by construction). Data were analysed as the literature analyses them (exposure fixed at baseline, follow-up from diagnosis), and by time-varying Cox and landmark analysis. Confounding by indication was added in a second scenario. Results Under immortal time bias alone the naive analysis returned a hazard ratio of 0.794 (95% simulation interval 0.743-0.851), median survival 16.8 versus 12.8 months. Time-varying Cox recovered 1.000 and landmark analysis 1.000-1.004. Bias scaled with the interval: 0.849 at 92 days, 0.715 at 174 days. Adding confounding, the naive estimate fell to 0.601 (0.560-0.644) at strength 0.5 and 0.356 (0.323-0.385) at strength 1.5, overlapping the published estimate; median survival 21.9 versus 8.7 months. Correcting immortal time alone left residual bias (hazard ratio 0.439). Conclusions The reported survival advantage of conversion surgery is reproducible where the operation does nothing; published estimates cannot distinguish benefit from bias. Resolving this requires individual patient data analysed with methods that assign person-time correctly, or completion of JCOG2301.

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Paired-surface spatial mechanomics links tissue stiffness maps to spatial transcriptomics

Ong, H. T.; Lou, Y.; Turley, J.; Hengst, R. M.; Ramli, M. F. H.; Shen, X.; Marlena, J.; Zhu, J.; Li, R.; Chan, C. J.; Young, J. L.

2026-08-31 bioengineering 10.64898/2026.08.29.748050 medRxiv
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Tissue mechanics influence diverse biological processes, yet directly linking stiffness measurements to spatially resolved molecular states in intact tissues remains challenging. Here we developed a paired-surface spatial mechanomics approach to map Young's modulus by nanoindentation on a fresh tissue surface and co-register the stiffness grid with 10x Genomics Visium HD spatial transcriptome bins from the immediately adjacent, parallel surface. Applied to the mouse ovary, which has spatially distinct compartments and undergoes extracellular matrix remodeling with cycle and age, the workflow generated >2,900 matched measurements across 21 regions of interest. Nanoindentation at 50-m grid spacing enabled millimeter-scale stiffness maps while balancing acquisition time in fresh tissues, with ~92 4-m transcriptome bins assigned to each stiffness value. Global and compartment-specific analyses associated stiffer regions with lower elastic fiber programs and higher inflammatory signaling, with age-dependent differences. This correlative strategy integrates experimentally measured mechanics with spatial omics in fresh tissues.

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Whole-body Super-resolution Functional and Molecular Imaging with Panoramic Photoacoustic-Ultrasound Tomography

Yao, R.; Husain, I.; Luo, J.; Huo, H.; Cai, X.; Wang, N.; Vu, T.; Li, J.; Xu, Y.; Menozzi, L.; Yang, J. J.; Lowerison, M.; Luo, X.; Song, P.; Yao, J.

2026-09-01 bioengineering 10.64898/2026.08.28.747673 medRxiv
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Photoacoustic (PA) and ultrasound (US) imaging provide complementary molecular, functional, and anatomical contrasts. Here, we present a panoramic PA-US imaging platform that integrates multispectral PA computed tomography (PACT) along with reflection-mode and transmission-mode US imaging through a single shared full-ring ultrasound array. We employ an ultrafast planewave transmission scheme in reflection-mode US for power Doppler (PWD) imaging and ultrasound localization microscopy (ULM). Additionally, we use the transmission-mode US to reconstruct a spatially resolved speed of sound (SoS) map that corrects both PA and US reconstruction. Such correction sharpens the resolution of PACT, suppresses the artifacts of PWD, and improves microbubble localization of ULM. Elevational scanning further enables whole-body volumetric imaging with co-registered PA and US contrasts. The integrated system maps photoswitchable DrBphP1-expressing tumors alongside their blood perfusion and oxygenation environment. Applying the platform to monitor unilateral renal ischemia-reperfusion injury, we report that microvascular perfusion and renal oxygenation recover at different rates. Collectively, we demonstrate that the integrated PA-US imaging platform provides a unified framework for multiparametric study of anatomy, perfusion, microvascular flow, oxygenation, and molecular activities.

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GLP-1/GIP Uptake, Indication, and Access Pathways Among US Adults in the Understanding America Study

Chaturvedi, R. R.; Gracner, T.; Perez-Arce, F.; Suen, S.-c.; Jin, J.; Orriens, B.; Pacula, R. L.; Sexton Ward, A.; Haile, R.; Kapteyn, A.

2026-09-02 endocrinology 10.64898/2026.08.28.26361368 medRxiv
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Importance: Evidence on GLP-1/GIP therapies is largely derived from trials enrolling selected populations or medical records that miss utilization outside healthcare channels. No nationally representative cohort has characterized real-world uptake, indications, and access. Objective: To characterize GLP-1/GIP prevalence, indication, clinical profile, and access. Design: Prospective cohort study with three GLP-1/GIP surveillance waves (March 2024, December 2024, October 2025). Setting: The Understanding America Study, an address-based, nationally representative panel of approximately 15,000 US adults aged 18+ years initiated in 2014. Participants: UAS participants responding to at least one surveillance wave (n=9150). Exposures: GLP-1/GIP use status (never vs any use, comprising current and former use), self-reported primary indication (diabetes, weight loss, or other), and access pathway (traditional vs non-traditional). Main Outcomes and Measures: Survey-weighted prevalence of GLP-1/GIP use, overall and by indication and access pathway; sociodemographic, cardiometabolic, treatment, and access characteristics; and smartwatch-derived resting heart rate, heart rate variability, maximum activity heart rate, step count, and sleep duration and variability. Results: Among n=9150 adults (1274 with any use; 60.9% female; median age 53 years), weighted prevalence increased 46%, from 8.2% (March 2024) to 12.0% (October 2025) representing 32 million. Weight-loss indications grew, reaching nearly half of use (4.1% to 5.6%); diabetes-indicated use was stable (5.3% to 5.4%). Users carried high cardiometabolic burden (obesity, 68.2%; diabetes, 53.6%) but diverged by indication: diabetes-indicated users were older (median, 59 vs 49 years), whereas weight-loss-indicated users were more often female (69.9% vs 51.3%) and healthier. One in three users (~9 million) had non-traditional access, especially in weight-loss-indicated users, of whom 33% had no conventional prescription; 41% used compounding, online, or foreign pharmacies; and, 43% lacked coverage. Non-traditional users were five times as likely to report an unlisted, likely compounded formulation (19.8% vs 4.1%). All p<0.05. Conclusions and Relevance: Real-world GLP-1/GIP use has grown rapidly and diversified substantially in indication, access, and population profile. One in 3 users obtained treatment through nontraditional channels largely invisible to claims data, raising long-term safety, efficacy, and coverage questions. GLIMMER provides a public, nationally representative longitudinal evidence base for future payer and provider decisions.

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Left ventricular hypertrophy, brain atrophy and cognitive decline in type 2 diabetes mellitus: Diabetes & Dementia (D2) cohort study

Brodtmann, A.; Patel, S.; Restrepo, C.; Khlif, M. S.; Werden, E.; Ellis, R.; Alsawaf, S.; Ekinci, E. I.; Srivastava, P. M.; Ramchand, J.; MacIsaac, R. J.; Churilov, L.; Burrell, L. M.

2026-09-02 cardiovascular medicine 10.64898/2026.08.31.26361868 medRxiv
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BACKGROUND People with type 2 diabetes mellitus (T2DM) are at higher risk of cerebral small vessel disease and left ventricular hypertrophy (LVH), potentially contributing to cognitive decline and dementia. We aimed to describe brain volume and cognitive trajectories over 2 years in a cohort of people with T2DM and to determine whether LVH causes increased brain atrophy and cognitive decline. METHODS Diabetes and Dementia (D2) study is a multicentre observational cohort study in Melbourne, Australia. Participants aged >50 years were recruited via 2 hospital outpatient clinics, 3 private clinics, and study advertisements. Participants with pre-existing cognitive impairment, life-limiting medical illness, and severe chronic renal impairment were excluded. Participants attended study visits for brain MRI, transthoracic echocardiography (TTE), and cognitive testing at baseline and 2 years. The exposure was LVH determined on baseline TTE. Pre-specified outcomes were total brain volume (TBV) change and cognitive decline (z-score change?-1 in any cognitive domain) over 2 years. Regression analyses examined associations between baseline variables and outcomes. A causal inference approach was utilized using inverse probability of treatment weighting to standardize for confounding covariates, excluding participants for non-positivity on age and baseline TBV. RESULTS Participants were recruited 20May2016 to 20March2020: 2378 screened, 702 eligible, 196 consented, 150 baseline and 123 2-year assessments with complete MRI, TTE, and cognitive data (17.4% attrition). At baseline, LVH was associated with female sex, older age, lower educational attainment, lower mood, hypertension, obesity, beta-blocker use, and smaller TBV. Participants with baseline cognitive impairment exhibited greater brain atrophy. Lower educational attainment, hypertension, and lower baseline cognitive scores were associated with cognitive decline. Causal inference analysis included 62 participants with no LVH (20(32%) women; mean [SD]=66.9[5.9] years), and 31 with LVH (17(55%) women, 67.4[5.4] years). LVH caused lower TBV change: standardized mean difference (95% CI) 6.3 (0.1, 12.5) cm3, P=.048. LVH had no effect on cognitive decline. CONCLUSIONS Brain atrophy and cognitive decline were associated with baseline cognitive impairment. LVH caused less brain atrophy and cognitive decline in people with T2DM. We conclude that guideline-directed LVH therapies such as beta-blockers have both cardioprotective (remodelling) and neuroprotective effects. TRIAL REGISTRATION ACTRN12616000546459 UTN: U1111-1181-6659

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An interpretable, formally verified point-of-care ultrasound risk equation for difficult videolaryngoscopy: development and internal validation

Oyarzun-Silva, R. A.; Hernandez-Hernandez, P.; Fernandez-Vaquero, M. A.; De Luis-Cabezon, N.

2026-09-02 anesthesia 10.64898/2026.08.28.26361621 medRxiv
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Background. Videolaryngoscopy still requires adjuncts or hyperangulated rescue in a clinically important minority, and bedside screening discriminates modestly. Point-of-care ultrasound (POCUS) of the anterior airway is a promising alternative, but existing prediction models are opaque or assume a pre-specified functional form. We developed and internally validated a parsimonious, fully disclosed POCUS risk equation whose form is recovered from data and whose structural properties are machine-checked by formal proof - to our knowledge the first formally verified clinical risk predictor - following TRIPOD+AI 2024. Methods. In a prospective single-centre, single-operator cohort of 259 adults undergoing elective videolaryngoscopy (no-Easy airway 68/259, 26.3%), Sequentially Thresholded Least Squares with bootstrap stability selection (B=300) screened a 71-term library of nine POCUS features and retained a seven-term logistic equation; a two-term bootstrap-stable model was pre-specified as robustness analysis. Internal validation used 5x10 repeated cross-validation plus temporal and device hold-outs, with pre-specified overfitting and optimism assessments. Five behavioural properties of the deployed equation were machine-checked in Lean 4. Results. Two interactions met the |c|/sigma_c>2 stability criterion: skin-to-epiglottis x skin-to-hyoid-bone distance and tongue volume x sagittal tongue area. The seven-term equation reached a 5x10 cross-validated C-statistic of 0.966 (optimism-corrected 0.968) and held across temporal and device hold-outs (0.94-0.97). Calibration-in-the-large matched prevalence, with cross-validated slope 0.90 attenuating to 0.625 out-of-time; standard recalibration restored 0.92 without loss of discrimination. The pre-specified two-term robustness model reproduced this performance (C-statistic 0.964-0.968; events-per-parameter 34; shrinkage 0.99), confirming the result is not an artefact of the screening stage. Net benefit over a clinical baseline was positive across 10-50% thresholds. All five Lean 4 theorems compiled without sorry. Conclusions. A sparse, formally verified POCUS equation predicts difficult videolaryngoscopy with high internally validated discrimination and quantified, modest overfitting. Because the equation was developed in a single-operator cohort and its inputs are operator-dependent, external validation requires prior harmonisation of the measurement protocol and operator credentialing.

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Glaucoma and Diabetes Mellitus: A Comparative Evaluation of Comorbid Effect on Tear Quantity among Patients in Owerri, Imo State, Nigeria.

Chukwuoha, C. M.; Ovenseri-Ogbomo, G.; Azuamah, Y. C.; Odimegwu, N. E.; Obioma-Elemba, J. E.; Ugwoke, G.; Nkeremuzor, E. C.; Eronini, Y.; Ikoro, N. C.; Esenwah, E. C.

2026-09-02 ophthalmology 10.64898/2026.08.30.26361782 medRxiv
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Abstract Objective: Glaucoma is a chronic disorder that impairs ocular health and may exacerbate ocular surface disease leading to tear film instability, dry eye symptoms and decreased quality of life. This study compared changes in tear quantity among glaucoma subjects living with and without diabetes mellitus, attending an eye clinic in Nigeria. Methods: A comparative cross sectional research design was used. 157 subjects which comprised 74 glaucoma subjects living with diabetes mellitus and 83 glaucoma subjects living without diabetes mellitus participated in the study. Tear quantity assessment included the Schirmer I test and tear meniscus height (TMH) measurement. Descriptive statistics, independent samples t-test and Chi-square test were used to examine the data at 0.05 level of significance. Results: Glaucoma subjects living with diabetes mellitus showed substantially decreased tear production (11.4 +/- 6.8 mm) compared with glaucoma subjects living without diabetes mellitus (19.6 +/- 9.6 mm; p < 0.001). Tear meniscus height in glaucoma subjects living with diabetes mellitus (0.8 +/- 0.3 mm) was significantly greater than in subjects living without diabetes mellitus (0.7 +/- 0.3 mm; p = 0.034). Conclusion: Diabetes mellitus dramatically deteriorates the ocular surface function in glaucoma subjects by decreasing tear production, altering the tear meniscus height and increasing the severity of ocular surface symptoms. Routine glaucoma care, especially in patients with diabetes mellitus, should include a full ocular surface evaluation including Schirmer I test, TBUT, TMH, and OSDI assessment to allow early detection and management of ocular surface disease, better treatment adherence, and improved visual outcomes. Keywords: Glaucoma, Diabetes Mellitus, Tear production, Tear Meniscus Height, Ocular Surface Disease.