Lab Animal

Cooperation in social species is shaped by ongoing social relationships, partner choice, and group interactions, demanding experimental systems that preserve the social context in which these behaviors unfold. Here we introduce the e-Seesaw, a wireless system for automated liquid reward delivery designed to support home-enclosure experiments on reward access distribution in common marmosets (Callithrix jacchus) with minimal human intervention. The apparatus combines a modular peristaltic pump with a Bluetooth-controlled trigger, allowing spatial separation between the site of action and the site of reward delivery while preserving group housing. We provide detailed design files, software, and assembly instructions to support reproduction and adaptation. In a proof-of-concept deployment across seven families, animals readily engaged with the device, producing a median of ~87 trigger activations per session. Engagement was concentrated early within sessions and remained largely stable across repeated deployments, including under increased action-reward separation. These results established the e-Seesaw as a flexible and reproducible platform for automated reward-delivery experiments in animals tested within their social groups, while reducing human involvement and avoiding fixed dyadic testing.

Background/ObjectivesThe integration of large language model (LLM)-based AI tools into veterinary clinical practice is rapidly increasing; however, no systematically derived taxonomy of veterinary AI query patterns has been established. This study aimed to develop and refine an exploratory taxonomy of veterinary AI query patterns across clinical stages through a structured expert-panel review process. MethodsAn exploratory cross-sectional expert panel study was conducted. 5,372 real-world query logs from a veterinary clinical AI chatbot deployed over eight months were analyzed using AI-assisted inductive coding to derive an initial taxonomy. The taxonomy was refined through literature review and subsequently reviewed by an expert panel of 38 veterinary professionals via structured online survey across five clinical stages. ResultsA taxonomy of 3 categories and 21 subtypes was established: Clinical Support Queries (Types A-H), Evidence-Based Research Queries (Types I-L), and Terminology and Drug Reference Queries (Types M-U). Type B (Differential Reasoning) had the highest overall frequency (57/188 first-choice responses), while Type D (Clinical Decision Support) was dominant immediately post-consultation (55.3%). Veterinary professionals with [&ge;]10 years of experience showed a higher frequency of Type G (Evidence Search) preference than those with <10 years of experience (18 vs. 4), while university-affiliated professionals demonstrated a distinct pattern dominated by Type G. ConclusionsTo our knowledge, no published study has previously established a veterinary-specific, clinical-stage-sensitive exploratory taxonomy of AI query patterns; this study addresses that gap. The findings provide a foundational framework for designing context-aware, stage-adaptive veterinary AI systems and benchmark evaluation tools.

Long-term, automated tracking of group-housed social animals using RFID (radio frequency identification) is a promising approach in ethological neuroscience. However, low-frequency (LF) RFID, while long-established in the field, is constrained by its inherent low data rates, which lead to two critical limitations: (1) compromised spatiotemporal resolution, and (2) the inability to identify multiple tags (animals) simultaneously. To address these limitations, we developed eeeHive, a high-frequency (HF) RFID-based animal tracking system with a fully custom hardware architecture that enables high-speed, multiplexed antenna polling and concurrent multi-tag reading. The polling time per antenna in eeeHive was 5.9 ms, with an additional 8.2 ms read time per tag. We applied the system to track 24 mice for one week, and six common marmosets for seven weeks. The system successfully tracked individuals even within dense clusters, revealing complex behavioral traits characterized by spatial utilization, temporal dynamics, behavioral regularity, and inter-individual relationships. Additional tests with Japanese fire-bellied newts and Nile tilapia juveniles demonstrated comparable tracking performance in aquatic environments. Taken together, eeeHive overcomes the inherent limitations of conventional LF RFID, establishing a powerful HF RFID-based platform for fine-scale behavioral tracking of group-housed animals across terrestrial and aquatic species.

Mass spectrometry is used to identify chemicals to which humans are exposed, but it cannot directly determine molecular structures. Instead, structures are inferred by matching experimental spectra to libraries of spectra constructed from analyses of pure reference compounds. However, the chemical space of human exposures far exceeds the amount of experimental library spectra. Here, we evaluate a reference-free strategy for confident identification of unknown molecules. Using fentanyl as a case study, we created a suspect library of over 1 billion computationally predicted fentanyl analogs and predicted molecular properties through machine learning, molecular dynamics, and density functional theory. Multi-dimensional spectra from a blinded analysis of a mock fentanyl tablet were matched with the predicted library, yielding an average of three candidate structures per measured analog, with six exact identifications. This work emphasizes the promise of reference-free molecular measurements for assessing human exposure by merging computational predictions with high-dimensional measurements.

ObjectiveChoosing between TNBS/ethanol enema and DSS free-drinking water protocols for establishing rat ulcerative colitis(UC) models remains a practical challenge in preclinical research. Beyond confirming that both methods induce colitis, no prior study has quantified the independent contribution of enema procedural trauma to inflammatory readouts, reported sex-stratified cytokine responses, or formally linked model-specific immune profiles to human UC endotypes. MethodsTen SPF-grade SD rats(half male and half female) were allocated to a normal control, a procedure-matched saline enema control(anesthesia and enema without chemical agent), a TNBS group(100 mg/kg TNBS + 50% ethanol enema), and a DSS group(3% DSS free-drinking, 7 days). Endpoint assessments included body weight, colon length, macroscopic and histological scoring(modified Macpherson criteria, 0-10), and serum TNF- and IL-6 by ELISA. Post-hoc exploratory analyses included sex-stratified cytokine sub-analysis and coefficient of variation(CV%) for each readout. ResultsBoth model groups successfully induced UC(P<0.05 vs. controls for all endpoints). Critically, the procedure-matched saline enema control confirmed that colonic inflammation in the TNBS group was attributable to the chemical agent rather than mechanical trauma. TNBS induced significantly higher TNF-(90.2{+/-}10.5 vs. 73.5{+/-}9.8 pg/mL, P<0.05) and IL-6(66.5{+/-}8.3 vs. 53.2{+/-}7.6 pg/mL, P<0.05) than DSS,consistent with Th1-polarized vs. innate barrier-disruption immune endotypes, respectively. Coefficient of variation analysis indicated greater intra-group variability in TNBS versus DSS, reflecting the procedural dependency of enema-based models. ConclusionA procedure-matched control design is essential for valid TNBS-vs.-DSS comparisons and has been systematically underutilized in prior studies. Based on immune endotype alignment, TNBS is recommended for screening T-cell-targeted therapies and acute anti-inflammatory agents, while DSS is recommended for epithelial barrier repair and microbiome-modulating interventions. A model-selection decision framework derived from these data is provided to guide preclinical study design.

BackgroundBispecific T-cell Engagers (TCEs) targeting B7H3 (CD276) show promise for solid tumors but are limited by systemic toxicities and poor tumor penetration. Intratumoral (IT) delivery is proposed as a solution, but the safety and spatial pharmacodynamics (PD) remain poorly defined in these malignancies. Spontaneous canine tumors serve as a highly translatable model for human therapeutic development due to its clinical, genetic, and immunological similarities to human patients. This study evaluates the feasibility of an IT-delivered B7H3:CD3 TCE in a trial that enrolls companion dogs with solid tumors. MethodsWe engineered a canine B7H3:CD3 TCE and validated its ability to induce T-cell activation and T-cell mediated cytotoxicity in vitro on several B7H3-expressing canine tumor cell lines. Two STS canine patients received intratumoral columnar injections of the TCE and saline (internal control) at fixed distance of 1.5cm using a custom-engineered multi-needle assembly. Safety was evaluated by physical examinations and hematological and biochemical changes in peripheral blood. PD response was analyzed by H&E and immunohistochemistry. ResultsIn vitro assays validated the cytotoxicity of the B7H3:CD3 TCE on B7H3+ canine tumor cell lines. TCE IT administration (7.83 g / 148.2 pmol) was well tolerated with no adverse events greater than Grade 1 and no evidence of systemic cytokine release or organ toxicity. Immunohistochemistry of tumors collected 7 days after TCE administration revealed a significant five-fold increase in CD3+ T-cell density at the TCE injection site (within 0.5 cm radius) compared to internal saline controls. ConclusionsThis study demonstrated the feasibility of evaluating pharmacodynamic response to IT delivery of B7H3:CD3 TCE, namely local T-cell accumulation. T-cell localization around the TCE injection site supports our hypothesis that effective IT immunotherapy might require enhanced volumetric coverage using multi-needle injections and/or co-stimulatory strategies to convert T-cell localization into a robust, sustained anti-tumor response.

Gene therapy has been the subject of extensive research following the advent of gene-editing technologies. Genetic disorders with difficult-to-target tissues, such as cystic fibrosis (CF), still face many challenges in developing efficacious gene therapy. The potential universal approach of gene replacement involves inserting a functional CFTR gene after generating DNA double strand breaks using gene editors such as CRISPR/Cas9. However, this strategy has not achieved clinical significance, as CRISPR/Cas9-mediated integration of CFTR is limited primarily by the infrequent activity of the homology-directed repair (HDR) pathway. To circumvent this limitation and improve CFTR transgene integration and expression, we explored a method of adding a second integration site, which we termed the dual-locus-targeting method. Using a helper-dependent adenoviral vector (HDAd)-delivered CRISPR/Cas9 system in porcine epithelial cells, we found that sequential delivery of two vectors, one targeting the CFTR locus and the other the genomic safe harbour site GGTA1, enhanced the integration efficiency of lacZ and CFTR donor genes to 16.5% and 3.4%, respectively. These results demonstrated a potential strategy to improve the efficacy of CFTR replacement for the development of a universal and permanent gene therapy treatment for CF lung disease. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=76 SRC="FIGDIR/small/731381v1_ufig1.gif" ALT="Figure 1"> View larger version (17K): org.highwire.dtl.DTLVardef@1774590org.highwire.dtl.DTLVardef@1782915org.highwire.dtl.DTLVardef@1d13b12org.highwire.dtl.DTLVardef@17d3f93_HPS_FORMAT_FIGEXP M_FIG C_FIG

Messenger RNA (mRNA) therapeutics have rapidly emerged as a transformative approach for treating a range of health challenges. Accelerated by the success of mRNA-lipid nanoparticle (LNP) vaccines during the COVID-19 pandemic, this platform holds promise beyond immunisation for the transient expression of therapeutic proteins in targeted tissues. Despite this promise, non-invasive delivery of mRNA to the brain, as with most therapeutics, remains a challenge due to the impermeability of the blood brain barrier. Here, we present a novel strategy to deliver neurotrophic factors to the brain via intranasal delivery of mRNA-LNP. As a proof of concept, we demonstrate that intranasal delivery of mRNA encoding the neurogenic factor BDNF (Brain Derived Neurotrophic Factor) enhances memory performance in both aged mice and a transgenic mouse model of Alzheimers disease. This approach offers a promising platform for delivering therapeutic proteins to the brain and opens new avenues for treating age-related and neurodegenerative disorders.

Intrathecal (IT) drug delivery is a critical technique for bypassing the blood-brain and blood-spinal cord barriers in preclinical CNS research. However, conventional rat catheterization methods suffer from high rates of neurologic complications, poor reliability, and unverified dosing due to epidural reflux and inconsistent supraspinal distribution. Our objective was to develop and validate an improved method for lumbar IT catheterization in rats that ensures distribution to the brain and to confirm supraspinal pharmacodynamic target engagement. We describe a refined microsurgical technique using dural puncture under direct visual control at the L6-S1 interlaminar space, a site chosen for its anatomical safety margin. The method uses a small-bore (0.33 mm OD) polyurethane (PU) catheter to minimize durotomy size, air-bubble tracking to compensate for catheter dead volume, and epidural sealing with Surgifoam(R) to minimize reflux. Visualization using Evans Blue dye confirmed complete neuraxial distribution from a single 30 {micro}L lumbar bolus injection, with dye reaching the ventral/dorsal brain cisterns. Pharmacodynamic validation of cortical exposure was achieved using an S6 kinase 1 (S6K1) inhibitor. Lumbar IT administration over a period of 6 hours via a pump resulted in significant supraspinal S6K1 engagement, demonstrated by a reproducible reduction in S6 phosphorylation in the cerebral cortex. HighlightsO_LIMethod for lumbar intrathecal catheterization in rats under direct visual control, using basic surgical tools C_LIO_LICNS distribution validated by Evans Blue dye reaching ventral and dorsal brain C_LIO_LIPharmacodynamic confirmation of supraspinal target engagement following lumbar intrathecal delivery of a small molecule kinase inhibitor C_LIO_LIServes as a faithful preclinical model for therapeutics intended for clinical intrathecal administration C_LIO_LIProvides a screening route for early-stage compounds not yet optimized for CNS penetrance, supporting efficacy testing prior to medicinal chemistry investment C_LI

Immunocastration, a non-surgical strategy based on active immunization against gonadotropin-releasing hormone (GnRH), effectively suppresses steroidogenesis and spermatogenesis. However, peptide vaccines targeting poorly immunogenic antigens such as GnRH often fail to elicit robust adaptive immune responses, requiring adjuvants or carrier proteins. Previously, we introduced Coated Bacterial Vaccines (CBVs), a platform that uses chemically inactivated Gram-positive bacteria to display recombinant antigens fused to the SlpA carboxy-terminal domain (dSLPA) on their surface. This system leverages natural pathogen-associated molecular patterns (PAMPs) to enhance immunogenicity without additional adjuvants. In this work, we extended the application of the CBVs platform to enhance the immune response against a poorly immunogenic GnRH-based peptide vaccine. GnRH-CBVs were formulated using inactivated Bacillus subtilis var. natto coated with a recombinant GnRH tandem-repeat-dSLPA fusion protein and administered to male BALB/c mice. A chitosan-adjuvanted GnRH-dSLPA formulation served as a positive control. GnRH-CBVs induced a strong Th2-biased humoral response, characterized by predominant IgG1 levels comparable to those achieved with chitosan. The resulting antibodies effectively neutralized endogenous GnRH, reducing steroidogenesis and spermatogenesis and inducing marked testicular histological alterations. These findings support CBVs as a promising strategy to enhance peptide vaccine immunogenicity for veterinary immunocastration.

Retinal and choroidal vascular diseases are major causes of vision loss that require frequent intravitreal anti-VEGF therapy. Anti-angiogenic peptide AXT107 demonstrated efficacy in preclinical studies and was advanced to the clinical stage. To provide for sustained delivery of the peptide and avoid complications with intravitreal injection, we evaluated suprachoroidal delivery of AXT107 microparticles (MP-AXT107). The original, soluble AXT107 formulation was ineffective at inhibiting laser-induced choroidal neovascularization (CNV) in our rat model and was consequently reformulated as microparticles. MP-AXT107 demonstrated high peptide incorporation efficiency, reproducible morphology, and physical and chemical stability for at least 9 months under refrigerated storage. In the rat CNV model, suprachoroidal MP-AXT107 significantly reduced neovascular area by approximately 60% relative to vehicle controls. Safety and durability were evaluated in a 9-month GLP toxicology study in Gottingen minipigs following a single suprachoroidal injection of vehicle or MP-AXT107 (0.125-1.25 mg/eye). Transient increases in IOP and mild ocular inflammatory findings were observed immediately following administration but resolved rapidly without lasting effects. No treatment-related adverse ocular findings were observed during the remainder of the study, and the highest tested dose (1.25 mg/eye) was established as the no-observed-adverse-effect level. Bioanalysis at study completion demonstrated persistent AXT107 localization primarily within choroid/RPE and scleral tissues, with no signs of systemic exposure. Collectively, these findings demonstrate that suprachoroidal delivery of MP-AXT107 enables sustained anti-angiogenic activity with favorable ocular safety and prolonged tissue retention, supporting further clinical development as a durable therapy for retinal and choroidal vascular diseases.

BackgroundAlkaptonuria (AKU) is a rare autosomal recessive metabolic disorder caused by deficiency of homogentisate 1,2-dioxygenase (HGD), resulting in systemic accumulation of homogentisic acid (HGA), ochronosis, and progressive multisystem disease. Although nitisinone (NTBC) lowers HGA levels, it does not correct the underlying genetic defect and induces hypertyrosinemia, highlighting the need for curative treatment approaches. We evaluated liver-directed adeno-associated virus (AAV)-mediated HGD gene therapy as a potential treatment for AKU. MethodsHgd-deficient (Hgd-/-) mice received liver-directed AAV2/8 vectors expressing codon-optimized human HGD under a liver-specific promoter. Reporter vectors were first used to assess hepatic biodistribution and transduction efficiency. Therapeutic efficacy was subsequently evaluated following AAV2/8-HGD administration (1 x 1012 vg/mouse). HGD expression was assessed by DNAscope, Western blotting, and RT-qPCR. Metabolic correction was determined using targeted LC-MS/MS and untargeted LC-HRMS metabolomics and compared with NTBC-treated Hgd-/- mice. ResultsReporter studies demonstrated liver-predominant transduction, with dose-dependent hepatocyte transduction reaching 89-93% at the highest dose. AAV2/8-HGD treatment produced robust hepatic HGD expression, with codon-optimized human HGD transcript levels approximately 33-fold higher than endogenous murine Hgd expression. Twelve weeks after treatment, plasma and urinary HGA levels were significantly reduced, with plasma HGA restored to near wild-type concentrations. Untargeted metabolomics further demonstrated marked reductions in HGA-derived phase I and II metabolites and revealed significant modulation of tricarboxylic acid cycle metabolism, consistent with partial restoration of metabolic homeostasis. Compared with NTBC-treated mice, AAV2/8-HGD achieved comparable plasma HGA reduction without elevation of upstream tyrosine pathway metabolites. ConclusionsLiver-directed AAV2/8-HGD gene therapy achieved substantial biochemical correction in Hgd-/- mice and restored metabolic flux without inducing hypertyrosinemia. These findings provide proof-of-concept supporting AAV-mediated HGD replacement as a promising long-term therapeutic strategy for AKU.

Returning individualized microbiome results in ways that are ethical, comprehensible, and useful remains under-explored in African settings. We nested a multi-site, mixed-methods study within the AWI-Gen Wave 2 gut microbiome sub-study of 1,801 women aged 42 - 86 years to engage the participants and provide feedback. All (1,001) participants from Agincourt and Soweto (South Africa) and Nairobi (Kenya) were invited to feedback meetings: 496 from Agincourt, 87 from Soweto, and 195 from Nairobi responded. Engagement strategies were tailored by site (small-group and home-based sessions, visual metaphors, Foldscopes, and local-language delivery). Using semi-structured discussions and structured observations analysed thematically in MAXQDA under COREQ, five cross-cutting themes emerged: (1) understanding of microbiome reports, (2) emotional responses to feedback, (3) perceived health relevance, (4) trust in research institutions, and (5) suggestions for improving engagement. Culturally grounded explanations and local-language facilitation enhanced comprehension and perceived relevance; English-heavy sessions were associated with more confusion. Most participants expressed satisfaction and described planned or enacted dietary and lifestyle changes, while frustration centred on long delays between sampling and feedback. Trust increased with transparency and individualized return of results but was often conditional on minimizing burdensome procedures such as repeat blood sampling (phlebotomy) and ensuring timely feedback. Engagement was feasible and low-cost (approximately USD 29-59 per participant) with site-specific resource needs. Limitations included constrained generalizability beyond the three study sites. Returning individualized microbiome findings in community settings in Africa is acceptable, feasible, and can motivate health-promoting behaviours when delivered promptly and in culturally and linguistically appropriate ways. IMPORTANCEMicrobiome studies rarely return individualized results in low-resource settings due to concerns about appropriate feedback and associated costs. This gap risks eroding trust and diminishing research impact. In three African communities, tailored feedback on gut microbiome profiles was provided to 778 women. By documenting a costed, multi-site engagement model and the themes influencing acceptance and actionability, this work offers a practical framework for ethically returning complex -omics results at scale in underrepresented populations - advancing scientific equity and strengthening community trust in microbiome research.

Anti-polyethylene glycol (PEG) hyperimmune pigs, immunized against PEG, provide a sensitive experimental model for the rare anaphylactic reactions induced by mRNA-PEGylated lipid nanoparticle (LNP)-based COVID-19 vaccines, such as Comirnaty. These pseudo-allergic infusion reactions can usually be prevented or attenuated by multicomponent anti-inflammatory premedication regimens; however, no established protocol exists for mRNA-LNP-based COVID-19 vaccines. The aim of the present study was to identify an effective premedication strategy capable of preventing or attenuating these reactions in hypersensitive subjects, using the hyperimmune porcine model. We compared the protective effects of individual pretreatment components; dexamethasone, famotidine, levocetirizine, acetaminophen, diclofenac, indomethacin, by analyzing hemodynamic endpoints (systemic and pulmonary arterial pressure, pulse pressure). All tested compounds modulated Comirnaty-induced anaphylactic responses; however, only cyclooxygenase (COX) inhibitors provided complete protection against anaphylaxis and other abnormal processes. This finding is consistent with the low incidence of infusion reactions to cancer nanomedicines at the Shaare Zedek Oncology Center in Israel which uses COX-inhibitors as premedication. Given that most currently used human infusion-reaction prevention protocols do not include COX inhibitors, and that steroid-containing regimens may potentially counteract vaccine efficacy, our results suggest that COX inhibitors may offer a clinically effective standalone option or form the basis of simplified premedication regimens for preventing this life-threatening condition.

Antibody-drug conjugates (ADCs) deliver cytotoxic payloads to tumors with antibody selectivity, yet all approved ADCs are administered by intravenous (IV) infusion despite a strong patient and clinical preference for subcutaneous (SC) delivery. SC administration would reduce treatment burden, but many ADC payloads are vesicants that cause tissue necrosis upon local release, a liability amplified, not mitigated, by the dispersion-enhancing excipients used for SC antibody formulations. We developed an injectable diacetyl-L-tartaric anhydride-functionalized chitosan hydrogel (TACT) that addresses this conflict by confining ADCs within a protective SC depot. TACT is compatible with clinically approved ADC formulations without drug-product modification and provides drug-to-antibody ratio (DAR)-dependent release kinetics that support a quantitative relationship with in vivo absorption timing. In direct comparison, recombinant human hyaluronidase (rHuPH20) co-formulated with vesicant ADCs caused severe tissue necrosis, whereas TACT prevented macroscopic injury while preserving antitumor efficacy comparable to intravenous dosing. TUNEL staining of injection sites showed that TACT attenuated peri-depot apoptotic injury 3-fold relative to T-DM1 alone and 2-fold relative to rHuPH20 co-formulation. In non-human primates, SC TACT achieved 78% relative bioavailability for total trastuzumab, reduced peak circulating T-DM1 catabolite (free DM1) exposure 7.6-fold compared to IV administration and produced only transient, self-resolving cutaneous reactions. These results identify depot-mediated confinement as a viable alternative to excipient-mediated dispersion for SC delivery of vesicant ADCs, demonstrated here for trastuzumab-based conjugates across two approved ADC drug products (T-DM1 and T-DXd, with non-cleavable MCC and cleavable peptide linkers), with supporting validation in a custom cleavable monomethyl auristatin E (MMAE) series. Additional validation with enfortumab vedotin (EV), a Nectin-4-targeting MMAE ADC, supported the applicability of this strategy beyond trastuzumab-based conjugates.

Microbiology education in veterinary curricula requires students to integrate complex foundational knowledge with clinical application, yet traditional lecture-based approaches often emphasize memorization over higher-order reasoning. In this study, we evaluated the impact of integrating clinically oriented, case-based instruction into a veterinary microbiology course within a Doctor of Veterinary Medicine curriculum. Using a quasi-experimental, multi-year design, student outcomes were compared before (2019, 2021) and after (2022-2025) implementation of case-based teaching while maintaining consistent course content, structure, and assessments. Introduction of clinical case examples was associated with significant and sustained improvements in student evaluations across multiple domains, including perceived relevance, critical thinking, and overall course value. Instructor-related evaluation metrics also improved. Student performance, measured by final course grades, increased following the intervention without evidence of grade inflation. These findings demonstrate that integrating clinically relevant case narratives into microbiology instruction enhances student engagement and student performance. This work highlights a practical and scalable strategy for improving microbiology education, particularly within veterinary and other health-professions curricula.

Hyperbranched poly(beta-amino ester) (hPBAE) nanoparticles represent a promising platform for nucleic acid delivery, particularly to the lungs. In this study, we evaluate the potential of hPBAE nanoparticles to deliver defective interfering RNA (diRNA) antivirals targeting betacoronaviruses under a range of formulations and storage conditions. hPBAE-diRNA nanoparticles demonstrated efficient cellular uptake of functional diRNA across diverse cell types, conferred protection against nuclease-mediated degradation, and exhibited low in vitro cytotoxicity. In vivo, these nanoparticles enabled effective delivery of functional diRNA to the lungs of golden hamsters without inducing adverse physiological effects. Collectively, these findings support hPBAE nanoparticles as a safe and effective platform for diRNA delivery for the treatment of respiratory viral infections. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=66 SRC="FIGDIR/small/721911v1_ufig1.gif" ALT="Figure 1"> View larger version (19K): org.highwire.dtl.DTLVardef@2fc386org.highwire.dtl.DTLVardef@1cda4f9org.highwire.dtl.DTLVardef@9f61borg.highwire.dtl.DTLVardef@1fc8461_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical Abstract.C_FLOATNO Defective interfering RNA was mixed with hyperbranched poly(beta-amino ester) nanoparticles and delivered to cells in vitro and to golden hamsters in vivo, to measure toxicity and the replication potential of the RNA. C_FIG

Background: Canadian biomedical core facilities (BCFs) provide researchers with access to advanced tools and unique technical expertise, essential for research. However, their role, sustainability, and impact remain poorly understood. We report on the evolution of model and existing state of Canadas 205 BCFs, examining challenges and benefits. Methods: Cross referencing of national databases by the Canadian Innovation Fund (CFI), and from data collected by the Canadian Network of Scientific Platforms (CNSP) allowed he identification of BCFs. Hand curation of these lists validated that cores are operational. To ensure cores not listed by CFI/CNSP were captured, research intensive institutions in Canada were independently searched to identify active cores. Results: There are currently 205 active and operational BCFs located across 9 provinces, which can be further stratified into 9 technical domains that describe the nature of services they provide. Quebec (80 cores) and Ontario (75 cores) have the highest confluence of BCFs, with Quebec having a higher ratio of cores per capita. Conclusions: While our data establishes the ubiquity of Canadian BCFs, we highlight substantial challenges including sustainability, governance, evaluation and the recognition of support for core scientists. Here, we establish a framework to address these challenges and to inform best practice, to optimize creation of impactful, accessible and functional biomedical core facilities.

BackgroundBreast cancer remains a significant therapeutic challenge due to the heterogeneity of tumor antigens and the presence of "immunologically cold" tumor microenvironments (TME) that resist conventional immunotherapy. mRNA vaccines offer a versatile platform for multi-epitope targeting, but their clinical utility is often limited by inherent instability and poor cellular internalization. ObjectiveTo design, characterize, and evaluate an R8-stabilized multi-epitope mRNA vaccine targeting HER2, MUC1, and Survivin for the treatment of aggressive breast cancer. MethodsA multi-epitope mRNA construct (R8-CTL1- 7-HTL1- 2) was designed and synthesized via in vitro transcription (IVT). The mRNA was complexed with an octa-arginine (R8) domain at an N/P ratio of 4:1 to form stable nanoparticles. Characterization included Minimum Free Energy (MFE) modeling and Dynamic Light Scattering (DLS). In vitro uptake and antigen expression were quantified in breast cancer cell lines. In vivo efficacy was assessed in female BALB/c mice (n=6) challenged with 4T1 cells, focusing on tumor growth inhibition, CD8+ T cell cytotoxicity, and intratumoral T cell infiltration (counts/mm2) over a 28-day period. ResultsThe mRNA construct exhibited high structural stability (MFE = -450 kcal/mol) and formed uniform nanoparticles (mean diameter [~]92 nm). R8-complexation significantly enhanced cellular uptake to 88%, resulting in robust relative expression of HER2 and MUC1. In vivo results demonstrated potent systemic immunity with a marked increase in CD8+ T cell cytotoxicity (p<0.05). Most notably, vaccinated mice showed a 65% increase in intratumoral T cell recruitment (from 1.4 to 2.3 counts/mm2), correlating with significant tumor growth suppression compared to the control group by Day 28. ConclusionThe R8-stabilized mRNA platform effectively overcomes the delivery barriers and "warms up" the immunosuppressive tumor microenvironment. By inducing high-density T cell infiltration and systemic cytotoxicity, this multi-epitope approach provides a promising therapeutic strategy for converting "cold" breast tumors into immunologically active, treatable targets.

Human Immunodeficiency Virus (HIV)-1 broadly neutralizing antibodies (bNAbs) have demonstrated clinical efficacy, but face manufacturing challenges associated with recombinant protein production and purification. Here, we present a ribonucleic acid (RNA)-encoded bNAb (RibobNAb) platform that enables in vivo antibody production of the clinically validated bNAb PGT121 via lipid nanoparticle (LNP) delivery, supporting rapid evaluation of Fc variants (LS, del294, LS-del294) in vitro and in vivo. We confirmed expression, sub-nanomolar HIV-1 Env binding, and potent neutralization across all RibobNAb variants in vitro. In mice, single RNA-LNP administrations yielded in vivo expression of all RibobNAb variants, with PGT121-LS exhibiting a prolonged half-life compared with PGT121. In non-human primates (NHPs), a single intravenous administration of PGT121-LS RNA-LNP was well tolerated without anti-drug antibody (ADA) formation over 180 days and resulted in PGT121-LS half-lives comparable to the reference protein. Single intramuscular administration showed RibobNAb expression but resulted in ADA development from Day 14 onwards and lower bioavailability. In vivo-expressed PGT121-LS RibobNAb retained identical antiviral functionality to PGT121-LS reference protein. An NHP pharmacokinetics model integrating RNA transfection and translation dynamics enabled allometric scaling and first-in-human dose prediction. We highlight RibobNAbs as an alternative to conventional purified protein antibodies for rapid development of bNAb-based therapeutic strategies.