The current state of animal models in research: A review

Hydrogel membranes in organ-on-a-chip devices: A review

Organ-on-a-chip (OoC) devices represent advanced in vitro models enabling to mimic the human tissue architecture function and physiology, providing a promising alternative to the traditional animal testing methods. These devices combine the microfluidics with soft materials, specifically hydrogel membranes (HMs) for mimicking the extracellular matrix (ECM) and biological barriers, such as the blood-brain barrier (BBB). Hydrogels are ideal biomaterials for OoC systems because of their tunable properties, biocompatibility, biodegradability, and microscale self-assembly. The integration of HMs with OoC devices provides an effective way to develop dynamic, biologically relevant environments for supporting living cells targeted at drug discovery, disease modeling, and personalized medicine. Recent advancements in fabrication technologies such as additive manufacturing (3D printing), photolithography, and bioprinting have additionally advanced development of such systems. This review aims to outline the role of HMs in OoC platforms, highlighting their material properties, self-assembly behavior, and also challenges associated with their fabrication. Additionally, we visualize and discuss the latest progress made in utilizing HMs for applications in tissue engineering, drug development, and biosensing, with a focus on their interface dynamics and structural self-organization. The future perspective on OoC technology has also been patterned in order to provide a broader image on integration of OoC and HMs with personalized medicine and advanced drug delivery systems.

Microfluidic organoid-slice-on-a-chip system for studying anti-cholangiocarcinoma drug efficacy and hepatorenal toxicity

Organ-chip technology, in contrast to cell culture and animal models, offers a promising platform for accelerating drug development. However, current chip designs simulate human organ functions and there is a lack of multi-organ chip designs that can simultaneously study drug efficacy and hepatorenal toxicity. Here, we developed a novel microfluidic multi-organ chip that integrated cholangiocarcinoma organoids (CCOs) with recellularized liver slices (RLS) and recellularized kidney slices (RKS), to simultaneously assess anti-cholangiocarcinoma drug efficacy and hepatorenal toxicity. Co-culture of patient-derived CCOs with RLS and RKS was successfully achieved for 7 days under flow conditions with enhanced liver and renal cell functions. Furthermore, an in vitro biomimetic model showed IC50 values of trastuzumab emtansine (T-DM1) of around 6.42 ± 7.34 μg mL-1 in four clinical cases, with one outlier of 77.77 μg mL-1 due to patient variability. Post-treatment, RLS and RKS cell viability remained high at 75.67% and 81.03%, respectively, suggesting low hepatorenal toxicity of T-DM1 for treating cholangiocarcinoma. Our study demonstrates the use of an organoid-slice-on-a-chip (OSOC) platform for personalized drug efficacy and toxicity assessment, particularly aiming at leveraging anticancer drugs for off-label use to save patient lives.

Temporomandibular joint degeneration arises spontaneously in STR/ort mice and is prevented by targeted aggrecanase inhibition

OBJECTIVE

Temporomandibular joint osteoarthritis (TMJ-OA) is painful and causes masticatory dysfunction, but current treatment is limited to symptom relief due to an incomplete appreciation of aetiology. Herein, we develop morphological and histological methods for quantitative evaluation of TMJ-OA severity and examine whether STR/Ort mice, which are genetically predisposed to spontaneous knee OA, exhibit protection against TMJ-OA upon genetic gain-of-function modification of an aggrecanase-selective mutant of tissue inhibitor of metalloproteinase (TIMP)-3.

DESIGN

We established morphological changes in mandibular condylar head adapted from human TMJ-OA criteria, and developed and verified the utility of TMJ-OA histological damage scoring adapted from the OARSI system. Mutant TIMP3 containing an extra alanine at the N-Terminus ([-1A] TIMP-3 was overexpressed in STR/Ort and CBA mice. Morphological changes in mandibular condyle and TMJ cartilage degradation were evaluated and quantified using micro-CT and histology in mice aged 10, 20 and 40 weeks.

RESULTS

Whilst no evidence of TMJ-OA was observed in STR/Ort mice aged 10 weeks, bone erosion and osteophyte formation appeared in the mandibular condyle by 20 weeks, with remarkable deformity and bone resorption at 40 weeks in STR/Ort, but not the parental CBA strain. TMJ-OA was less severe in 40 week-old [-1A]TIMP-3 overexpressing STR/Ort and CBA compared to wild-type mice.

CONCLUSIONS

Using our new mouse TMJ-OA scoring system we have found that OA affects joints other than the knee in the STR/Ort strain. Genetic gain-of-function modification of STR/Ort mice with an aggrecanase-selective mutant of tissue inhibitor of metalloproteinase (TIMP)-3 also affords in vivo chondroprotection against this TMJ-OA.

Patient-Oriented In Vitro Studies in Duchenne Muscular Dystrophy: Validation of a 3D Skeletal Muscle Organoid Platform

Background: Three-dimensional skeletal muscle organoids (3D SkMO) are becoming of increasing interest for preclinical studies in Duchenne muscular dystrophy (DMD), provided that the used platform demonstrates the possibility to form functional and reproducible 3D SkMOs, to investigate on potential patient-related phenotypic differences. Methods: In this study, we employed fibrin-based 3D skeletal muscle organoids derived from immortalized myogenic precursors of DMD patients carrying either a stop codon mutation in exon 59 or a 48-50 deletion. We compared dystrophic lines with a healthy wild-type control (HWT) by assessing microtissue formation ability, contractile function at multiple timepoints along with intracellular calcium dynamics via calcium imaging, as well as expression of myogenic markers. Results: We found patient-specific structural and functional differences in the early stages of 3D SkMO development. Contractile force, measured as both single twitch and tetanic responses, was significantly lower in dystrophic 3D SkMOs compared to HWT, with the most pronounced differences observed at day 7 of differentiation. However, these disparities diminished over time under similar culturing conditions and in the absence of continuous nerve-like stimulation, suggesting that the primary deficit lies in delayed myogenic maturation, as also supported by gene expression analysis. Conclusions: Our results underline that, despite the initial maturation delay, DMD muscle precursors retain the capacity to form functional 3D SkMOs once this intrinsic lag is overcome. This suggests a critical role of dystrophin in early myogenic development, while contraction-induced stress and/or an inflammatory microenvironment are essential to fully recapitulate dystrophic phenotypes in 3D SkMOs.

Cell therapy for liver disorders: past, present and future

The liver fulfils a plethora of vital functions and, due to their importance, liver dysfunction has life-threatening consequences. Liver disorders currently account for more than two million deaths annually worldwide and can be classified broadly into three groups, considering their onset and aetiology, as acute liver diseases, inherited metabolic disorders and chronic liver diseases. In the most advanced and severe forms leading to liver failure, liver transplantation is the only treatment available, which has many associated drawbacks, including a shortage of organ donors. Cell therapy via fully mature cell transplantation is an advantageous alternative that may be able to restore a damaged organ's functionality or serve as a bridge until regeneration can occur. Pioneering work has shown that transplanting adult hepatocytes can support liver recovery. However, primary hepatocytes cannot be grown extensively in vitro as they rapidly lose their metabolic activity. Therefore, different cell sources are currently being tested as alternatives to primary cells. Human pluripotent stem cell-derived cells, chemically induced liver progenitors, or 'liver' organoids, hold great promise for developing new cell therapies for acute and chronic liver diseases. This Review focuses on the advantages and drawbacks of distinct cell sources and the relative strategies to address different therapeutic needs in distinct liver diseases.

Electrical hydrogel: electrophysiological-based strategy for wound healing

Wound healing remains a significant challenge in clinical practice, driving ongoing exploration of innovative therapeutic approaches. In recent years, electrophysiological-based wound healing strategies have gained considerable attention. Specifically, electrical hydrogels combine the synergistic effects of electrical stimulation and hydrogel properties, offering a range of functional benefits for wound healing, including antibacterial activity, real-time wound monitoring, controlled drug release, and electrical treatment. Despite significant progress made in electrical hydrogel research for wound healing, there is a lack of comprehensive, systematic reviews summarizing this field. In this review, we survey the latest advancements in electrical hydrogel technology. After analyzing the mechanisms of electrical stimulation in promoting wound healing, we establish a novel classification framework for electrical hydrogels based on their operational principles. The review further provides an in-depth evaluation of the therapeutic efficacy of these hydrogels in various types of wounds. Finally, we propose future directions and challenges for the development of electrical hydrogels for wound healing.

An Elastase Inhibitor ShSPI from Centipede Attenuates Bleomycin-Induced Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease characterized by the fibrotic thickening of the alveolar walls, resulting in compromised gas exchange, restricted ventilation, and respiratory failure. It has been indicated that elastase inhibitors reduced the severity of IPF by neutralizing excessive elastase levels in the lungs. ShSPI is an elastase inhibitor derived from centipede toxin. The present study evaluates the therapeutic effects of ShSPI in a bleomycin-induced idiopathic pulmonary fibrosis model. According to the results, ShSPI markedly reduced the weight loss, showing the improvement of health status in bleomycin-induced mice. Its robust antifibrotic effects were evidenced by the mitigation of alveolar structural damage, reduction in inflammatory cell infiltration, inhibition of collagen deposition, and suppression of fibrotic nodule formation. ShSPI effectively attenuated inflammatory responses by downregulating pro-inflammatory factors (IL-6, IL-1β, and MCP-1) and upregulating the anti-inflammatory factor interleukin-10 (IL-10). After delivered via inhalation, ShSPI exhibited favorable pharmacokinetic properties. It could be detected at 8 h at doses of 1 mg/kg and achieved maximum plasma concentrations (Cmax) of 188.00 ± 64.40 ng/mL in vivo. At high doses (160 mg/kg), ShSPI maintained a strong safety profile, with no detectable toxicity observed. This feature shows the therapeutic potential of ShSPI in the treatment of idiopathic pulmonary fibrosis and provides valuable evidence for its development as a novel peptide-based therapy.

SNAP25-dependent membrane trafficking of the Kv1.5 channel regulates the onset of atrial fibrillation

Synaptosomal-associated protein 25 kDa (SNAP25) is essential for vesicular trafficking and protein docking at presynaptic membranes in the nervous system, yet its role in the heart remains poorly understood. Here, we show an unrecognized function of SNAP25, which is selectively expressed in the atria, in regulating atrial electrical remodeling and the onset of atrial fibrillation (AF). SNAP25 protein is downregulated in the atria of AF patients. Cardiomyocyte-specific knockout of SNAP25 in male mice significantly shortens the atrial effective refractory period and action potential duration (APD), increasing susceptibility to AF, which is attributed to elevated Kv1.5 current and membrane expression. Blocking Kv1.5 channels effectively restores atrial APD and reduces AF incidence. Mechanistically, SNAP25 deficiency reduces the internalization of Kv1.5 from the cell surface membrane to early endosomes. In human iPSC-derived atrial cardiomyocytes, SNAP25 deficiency similarly elevates arrhythmic activity and accelerates repolarization. In conclusion, this study reveals that SNAP25 regulates AF susceptibility by controlling the trafficking of the atrial-specific Kv1.5 channel, highlighting SNAP25 as a promising therapeutic target for atrial arrhythmias.

Humanized Major Histocompatibility Complex Transgenic Mouse Model Can Play a Potent Role in SARS-CoV-2 Human Leukocyte Antigen-Restricted T Cell Epitope Screening

Background: COVID-19, caused by SARS-CoV-2, poses a significant threat to human health. Vaccines designed for T-cell epitopes play an important role in eliminating the virus. However, T cell epitope screening often requires the use of a large number of peripheral blood mononuclear cells (PBMCs) from infected or convalescent patients, and if MHC humanized mice can be used for epitope screening, they will not have to wait for enough PBMCs to be available to screen for epitopes, thus buying time for epitope confirmation and vaccine design. Methods: In this study, we used SARS-CoV-2 BA.5 to infect HLA-A11/DR1, C57BL/6, hACE2 mice, and detected body weight changes, viral load, and pathological changes after infection. Fourteen days after the HLA-A11/DR1 and C57BL/6 mice were immunized against inactivated viruses, IgG antibodies were detected in mouse serum using ELISA, and IFN-γ produced by peptide stimulation of splenocytes was detected by ELISpot. Results: There is no obvious pathogenic phenotype of SARS-CoV-2 infection in HLA-A11/DR1 mice. Specific IgG antibodies were detected in serum after immunization of inactivated virus in both HLA-A11/DR1 and C57BL/6 mice, but specific IFN-γ was detected in splenocytes of HLA-A11/DR1 mice. Conclusions: Although HLA-A11/DR1 mice are unable to replicate the virus effectively in vivo, they are able to generate cellular immune responses after immunization inactivated viruses. Therefore, it can be used as a tool to substitute for human PBMCs in epitope screening, thus shortening the timeliness of T cell epitope screening and obtaining the immunogenicity information of new epitopes in a timely manner.

Engineered Endometrial Clear Cell Cancer-on-a-Chip Reveals Early Invasion-Metastasis Cascade of Cancer Cells

Endometrial clear cell cancer (ECCC) is an extremely rare and highly malignant subtype of endometrial cancer. For most ECCC patients, cancer metastasis is the major cause of death. To date, due to the complexity of cancer evolution and the small number of cases, the metastasis of ECCC at the early stage remains largely unknown. Herein, we modeled the early invasion-metastasis cascade of ECCC by coculturing the ECCC patient-derived tumor cells (PDTCs) and primary human vascular endothelial cells on a microfluidic chip. With the chip, we for the first time replicated the dynamic migration of PDTCs into the surrounding stroma, including the intravasation and extravasation of PDTCs through the capillaries/microvessels, and presented the changes in the morphology and permeability of capillaries, with the decreased diameter and the increased permeability after cancer metastasis. We found that PDTCs were more invasive than the common endometrial adenocarcinoma cells. In addition, we preliminarily explored the inhibition of drugs on the early PDTC infiltration. This study provides new ideas for better understanding of ECCC evolution.

Exogenous Alpha-Ketoglutaric Acid Alleviates the Rabbit Dermal Papilla Cell Oxidative Damage Caused by Hydrogen Peroxide Through the ERK/Nrf2 Signaling Pathway

As an endogenous metabolite, α-ketoglutarate (AKG) exhibits potent antioxidant properties, yet its molecular mechanisms remain unclear. Dermal Papilla Cells (DPCs), functioning as the regulatory hub of hair follicle morphogenesis, serve as a pivotal model system for deciphering follicular functionality and regeneration mechanisms through their orchestration of signaling networks. Using a hydrogen peroxide (H2O2)-induced oxidative stress model in DPCs, we investigated AKG's protective effects. AKG attenuated H2O2-triggered reactive oxygen species (ROS) overproduction, restored mitochondrial membrane potential, and suppressed apoptosis-related protein dysregulation. It enhanced cellular stress resistance by increasing the Bcl-2/Bax ratio, boosting antioxidant levels, and inhibiting inflammation. Mechanistically, H2O2 activated the Nrf2 pathway, while AKG amplified Nrf2 nuclear translocation and expression. Crucially, ERK inhibition abrogated AKG-mediated Nrf2 regulation, intensifying ROS accumulation and cell death. These results identify the ERK/Nrf2 axis as central to AKG's antioxidative cytoprotection. This study advances AKG's therapeutic potential and deepens insights into its multifunctional roles.

A novel antibody against GPIbα inhibits platelet function and thrombosis without increasing bleeding

Glycoprotein Ibα (GPIbα), the initiation protein of arterial thrombosis, was selected as a target for developing new antiplatelet drugs to prevent and treat arterial thrombosis. However, no anti-GPIbα drug is used successfully in clinical. We used human platelets as an antigen to immunize mice and obtained mouse anti-human GPIbα antibody 9C9. The chimeric antibody 1A09 was constructed, and the antibody binding sites were validated, before employing 3D modeling. Following design of a humanized anti-GPIbα, a mouse-derived antibody was mutated into a human sequence to construct the humanized anti-GPIbα antibody SZ003. ELISA, western blot, platelet aggregation, and thrombus model experiments were used to test the specificity, affinity, safety, and thrombus inhibition effects. The experimental results showed that SZ003 bound to GPIbα, inhibited GPIbα-mediated platelet aggregation, and induced in vivo platelet clearance. Furthermore, SZ003-Fab inhibited GPIbα-mediated platelet aggregation and thrombosis but did not induce in vivo platelet clearance, prolong bleeding time in mouse tails, nor have cytotoxic effects on human platelets. The Fab fragment of anti-human GPIbα humanized antibody SZ003 effectively inhibited GPIbα receptor-mediated platelet activation and thrombosis in vivo without leading to thrombocytopenia and bleeding. Therefore, SZ003-Fab has clinical value as a novel antithrombotic drug to treat arterial thrombus-related diseases.

Intranasal amyloid model of Alzheimer's disease - potential opportunities and challenges

Amyloid beta 1-42 (Aβ1-42) peptide is one of the most studied disease-related amyloidogenic peptides implicated in the pathophysiology of Alzheimer's disease (AD). Despite significant scientific breakthroughs in the recent past, the existing non-transgenic animal models do not demonstrate accurate pathology of AD progression. This review has presented a concise mechanistic understanding of the intranasal amyloid-based animal model of AD, along with its advantages, challenges, and major limitations. Furthermore, discussions on how to combat these challenges to pave the road toward developing novel therapeutics for AD, have also been included. Preclinical exploration of repeated intranasal amyloid-beta exposure would certainly aid the translational development of a robust animal model of AD. This will also provide a better understanding of disease progression and pathology in the intranasal animal model.

Genomic-transcriptomic analysis identifies the Syrian hamster as a superior animal model for human diseases

BACKGROUND

The Syrian hamster (Mesocricetus auratus) has shown promise as a human diseases model, recapitulating features of different human diseases including COVID-19. However, the landscape of its genome and transcriptome has not been systematically dissected, restricting its potential applications.

RESULTS

Here we provide a complete analysis of the genome and transcriptome of the Syrian hamster and found that its lineage diverged from that of the Chinese hamster (Cricetulus griseus) around 29.4 million years ago. 21,387 protein-coding genes were identified, with 90.03% of the 2.56G base pair sequence being anchored to 22 chromosomes. Further comparison of the transcriptomes from 15 tissues of the Syrian hamster revealed that the Syrian hamster shares a pattern of alternative splicing modes more similar to humans, compared to rats and mice. An integrated genomic-transcriptomic analysis revealed that the Syrian hamster also has genetic and biological advantages as a superior animal model for cardiovascular diseases. Strikingly, several genes involved in SARS-COV-2 infection, including ACE2, present a higher homology with humans compared to other rodents and show the same function as their human counterparts.

CONCLUSION

The detailed molecular characterisation of the Syrian hamster in the present study opens a wealth of fundamental resources from this small rodent for future research into human disease pathology and treatment.

Free-Floating Human Lung Organoids Derived from Induced Pluripotent Stem Cells

Lung diseases are one of the leading causes of death worldwide, and the global burden of these respiratory diseases continues to increase. Therefore, there is a need for accurate models for basic and translational research. In addition to animal models, the development of alternative in vitro model systems is progressing rapidly, ranging from advanced lung cell cultures to complex tissue-engineered lungs. Human lung organoids have become easily transferable three-dimensional in vitro model systems for lung disease modeling. Here, we present a detailed protocol for a rather simple and therefore very practical but reliable method to generate lung organoids from induced pluripotent stem cells (iPSCs) without relying on a matrix, which would represent a step forward toward animal-origin and/or component-free in vitro modeling.

Impact of different anesthetic protocols during anesthesia for the establishment of a porcine model of acute kidney injury

BACKGROUND

During the establishment of a model of acute kidney injury (AKI) in pigs, we observed a high prevalence of malignant hyperthermia (MH). These complications led us to refine the anesthetic protocol. This publication describes the impact of the choice of anesthetics on the results obtained.

METHODS

Pigs were euthanized at the end of the procedure, without recovery from anesthesia. Three anesthetic protocols were used: sevoflurane inhalation (ProtocolA, n = 5), a combination of ketamine, medetomidine and diazepam by intravenous infusion (ProtocolB, n = 5), and a combination of ketamine, diazepam, medetomidine, glucose, and noradrenaline (ProtocolC, n = 5). All pigs received morphine for analgesia. AKI was induced by interrupting renal perfusion for 90 min. MH was diagnosed based on clinical and biological parameters.

RESULTS

All MH pigs belonged to ProtocolA. MH pigs showed significantly higher maximum rectal temperature (p = 0.04), maximum expired carbon dioxide (CO2; p = 0.04), maximum heart rate (HR; p = 0.03), plasma concentration of creatinine and potassium (p < 0.0001). Protocol A pigs had a significantly higher maximum HR (p = 0.01) and hyperkalemia compared to the two other groups (ProtocolB, p = 0.005 and ProtocolC, p < 0.0001). Pigs from ProtocolA had a significantly lower minimum mean arterial pressure (MAP) than ProtocolC group (p = 0.03) and MAP remained below 60 mmHg for longer (p = 0.004). In ProtocolB, minimum glycemia was lower than other groups (p = 0.01).

CONCLUSION

Sevoflurane use was associated with the occurrence of MH, hemodynamic alterations and changes in plasma concentration of creatinine and potassium. These modifications can have a major impact on the validation of an experimental AKI model.

A systematic review and embryological perspective of pluripotent stem cell-derived autonomic postganglionic neuron differentiation for human disease modeling

Human autonomic neuronal cell models are emerging as tools for modeling diseases such as cardiac arrhythmias. In this systematic review, we compared 33 articles applying 14 different protocols to generate sympathetic neurons and 3 different procedures to produce parasympathetic neurons. All methods involved the differentiation of human pluripotent stem cells, and none employed permanent or reversible cell immortalization. Almost all protocols were reproduced in multiple pluripotent stem cell lines, and over half showed evidence of neural firing capacity. Common limitations in the field are a lack of three-dimensional models and models that include multiple cell types. Sympathetic neuron differentiation protocols largely mirrored embryonic development, with the notable absence of migration, axon extension, and target-specificity cues. Parasympathetic neuron differentiation protocols may be improved by including several embryonic cues promoting cell survival, cell maturation, or ion channel expression. Moreover, additional markers to define parasympathetic neurons in vitro may support the validity of these protocols. Nonetheless, four sympathetic neuron differentiation protocols and one parasympathetic neuron differentiation protocol reported more than two-thirds of cells expressing autonomic neuron markers. Altogether, these protocols promise to open new research avenues of human autonomic neuron development and disease modeling.

Intravenous injection of PCSK9 gain-of-function mutation in C57BL/6J background mice on Angiotensin II-induced AAA

OBJECTIVE

This study was performed to compare the incidence of Angiotensin II (Ang II)-induced abdominal aortic aneurysms (AAA) between intravenous and intraperitoneal injection of AAV8.mPCSK9D377Y in wild-type (WT) mice with C57BL/6J background and the pathological differences of above model in WT and ApoE-/- mice.

DESIGN

Male WT mice were injected intraperitoneally or intravenously with either a AAV8.null or AAV8.mPCSK9D377Y. Two weeks after injection, all WT mice were infused with Ang II, and simultaneously age-matched male ApoE-/- mice were infused with saline or Ang II for 4 weeks.

RESULTS

Compared with intraperitoneal injection of AAV8.mPCSK9D377Y for AAA model in WT mice, a higher incidence of Ang II-induced AAA, increased blood pressure (BP) and lipid concentration, lower collagen deposition and up-regulated inflammation response were shown by intravenous injection, which was similar to ApoE-/- mice infused with Ang II.

CONCLUSION

AAV8.mPCSK9D377Y infected male WT mice intravenously facilitate a high incident and comparable severity of Ang II-induced AAA which could be greatly expedites AAA studies on a gene of interest.

Guidance on the assessment of the functionality of biomaterials for periodontal tissue regeneration: Methodologies and testing procedures

Innovative biomaterials and tissue engineering strategies show great promise in regenerating periodontal tissues. This guidance provides an overview and detailed recommendations for evaluating the biological functionality of these new biomaterials in vitro, focusing on mineralization, immunomodulatory effects, cellular differentiation, and angiogenesis. Additionally, it discusses the use of in vivo experimental models that mimic periodontitis and scrutinizes methods such as osteogenic differentiation, immunomodulation, and anti-inflammatory responses to assess the effectiveness of these biomaterials in promoting periodontal tissue reconstruction. The guidance also addresses translating these findings to clinical applications, including using large animal models. This article aims to provide general recommendations for assessing the biological performance of novel materials and scaffold-based strategies using in vitro and in vivo (animal models), examining their advantages, disadvantages, and methodologies to guide effective research and clinical translation of regenerative treatments in periodontology.

An ex vivo and in vitro investigation of extracellular vesicle interactions with B cells of Macaca nemestrina and humans

Extracellular vesicles may modify recipient cell behavior through multiple mechanisms, including interacting with the cell surface or internal membrane components and delivering luminal cargo to the cytoplasm. Here, we use a previously established ex vivo approach to investigate the cellular fate of EVs spiked into whole blood samples from nonhuman primate (NHP) and human donors and contrast these findings with results from in vitro assays. We report that EVs are internalized by NHP and human B cells while also associating to some degree with other PBMCs. EVs exhibit greater association with B cells in ex vivo whole blood compared to isolated B cells, suggesting that blood components may promote EV interactions or that cell isolation factors may inhibit this association. Cellular uptake of EVs involves clathrin-dependent endocytosis and may be aided by other pathways, including direct EV-cell membrane fusion. Overall, our data suggest that EV association, including uptake, by B cells occurs in at least two primate species. These findings highlight the potential to develop new strategies to either enhance or inhibit EV tropism toward B cells.

Peering into the mind: unraveling schizophrenia's secrets using models

Schizophrenia (SCZ) is a complex mental disorder characterized by a range of symptoms, including positive and negative symptoms, as well as cognitive impairments. Despite the extensive research, the underlying neurobiology of SCZ remain elusive. To overcome this challenge, the use of diverse laboratory modeling techniques, encompassing cellular and animal models, and innovative approaches like induced pluripotent stem cell (iPSC)-derived neuronal cultures or brain organoids and genetically engineered animal models, has been crucial. Immortalized cellular models provide controlled environments for investigating the molecular and neurochemical pathways involved in neuronal function, while iPSCs and brain organoids, derived from patient-specific sources, offer significant advantage in translational research by facilitating direct comparisons of cellular phenotypes between patient-derived neurons and healthy-control neurons. Animal models can recapitulate the different psychopathological aspects that should be modeled, offering valuable insights into the neurobiology of SCZ. In addition, invertebrates' models are genetically tractable and offer a powerful approach to dissect the core genetic underpinnings of SCZ, while vertebrate models, especially mammals, with their more complex nervous systems and behavioral repertoire, provide a closer approximation of the human condition to study SCZ-related traits. This narrative review provides a comprehensive overview of the diverse modeling approaches, critically evaluating their strengths and limitations. By synthesizing knowledge from these models, this review offers a valuable source for researchers, clinicians, and stakeholders alike. Integrating findings across these different models may allow us to build a more holistic picture of SCZ pathophysiology, facilitating the exploration of new research avenues and informed decision-making for interventions.

Deciphering CSU pathogenesis: Network toxicologyand molecular dynamics of DOTP exposure

OBJECTIVE

This study elucidated the molecular mechanisms underlying chronic spontaneous urticaria (CSU), potentially induced by the food and environmental pollutant dioctyl terephthalate (DOTP), through the application of network toxicology and molecular dynamics simulations.

METHODS

The structural analysis of DOTP was conducted in PubChem, with target prediction executed via Swiss Target Prediction and SuperPred, and target identification standardized using UniProt. A PPI network analysis identified core disease-related targets using STRING and Cytoscape. GO and KEGG analyses were utilized to explore target functions, particularly in inflammation and immune response pathways. AutoDock was employed for molecular docking to predict DOTP's binding to core targets, followed by molecular dynamics simulations with Gromacs to observe detailed interactions and conformational changes in the target proteins.

RESULTS

The study identified 38 potential targets associated with CSU and highlighted six core targets-EGFR, BCL2, NFKB1, CASP3, ERBB2, and mTOR-through PPI network analysis. GO and KEGG analyses illuminated the roles of these targets in biological processes, cellular components, molecular functions, and signaling pathways, with a particular emphasis on the PI3K-Akt signaling pathway. Molecular docking demonstrated strong binding affinities between DOTP and the core targets, while molecular dynamics simulations confirmed the stable binding of DOTP to these targets, with exceptional stability observed in its interaction with the mTOR protein.

CONCLUSION

This study clarifies the potential molecular mechanisms of DOTP-induced CSU and underscores the efficacy of network toxicology, molecular docking, and molecular dynamics simulations in assessing the toxicity of food and environmental pollutants and their related molecular biological mechanisms. These findings offer new insights for future research, enhance our comprehension of the potential health impacts of food and environmental pollutants, and establish a scientific foundation for the development of prevention and treatment strategies.

Exploring the potential and limitations of artificial intelligence in animal anatomy

BACKGROUND

Artificial intelligence (AI) is revolutionizing veterinary medicine, particularly in the domain of veterinary anatomy. At present, there is no existing review article in the literature that examines the prospects and challenges associated with the use of AI in animal anatomy education.

STUDY DESIGN

Narrative review.

OBJECTIVE

This review article explores the prospects and drawbacks of AI applications in veterinary anatomy. Anatomy and AI-powered diagnostic systems enhance clinical examination, diagnosis, and treatment by analyzing vast datasets, improving accuracy, and detecting subtle anomalies.

METHODS

We reviewed and analyzed recent literature on AI applications in veterinary anatomy education, emphasizing their potential, limitations, and future directions..

CONCLUSION

In veterinary anatomy education, AI integrates advanced tools like three-dimensional (3D) models, virtual reality (VR), and augmented reality (AR), offering dynamic and interactive learning experiences to students as well as the faculty of veterinary institutions across the globe. Despite these advantages, AI faces challenges such as the need for extensive, high-quality data, potential biases, and issues with algorithmic transparency. Additionally, virtual dissection and educational tools may impact hands-on learning and ethical and legal concerns regarding data privacy must be addressed. Balancing AI integration with traditional skills and addressing these challenges will maximize AI's benefits in veterinary anatomy and ensure comprehensive veterinary care.

DMEM and EMEM are suitable surrogate media to mimic host environment and expand leptospiral pathogenesis studies using in vitro tools

Pathogenic Leptospira species can survive and thrive in a wide range of environments. Distinct environments expose the bacteria to different temperatures, osmolarities, and amounts and sources of nutrition. However, leptospires are mostly cultured, in a laboratory setting under in vitro conditions that do not reflect natural environments. This constraint on laboratory cultures limits the applicability of in vitro studies to the understanding of even simple pathogenic processes. Here we report, investigate, and identify a medium and conditions that mimic the host environment during leptospirosis infection, expanding the available in vitro tools to evaluate leptospiral pathogenesis. We quantified genome-wide gene expression of pathogenic Leptospira interrogans cultured in different in vitro media compositions (EMJH, DMEM, EMEM, and HAN). Using EMJH as standard, we compared gene expression in these compositions to genome-wide gene expression gathered in a host environment: whole blood (WB) of hamsters after infection with pathogenic leptospires. Leptospires cultured in DMEM and EMEM media shared 40% and 47% of all differentially expressed genes (DEGs) of leptospires present within WB (FDR<0.01), while leptospires cultured in HAN media only shared 20% of DEGs with those from WB. Furthermore, gene and pathway expression of leptospires cultured on DMEM and EMEM media exhibited a better correlation with leptospires grown in WB, including promoting expression of a similar leptospiral lipid A profile to the one identified directly in host tissues. Taken together, these results indicate that commercial cell-culture media EMEM or DMEM are better surrogates for in vivo pathogenic studies than EMJH or HAN media in Leptospira. These alternative culture conditions, using media that are a standard supply worldwide, provide a reproducible and cost-effective approach that can accelerate research investigation and reduce the number of animal infections necessary for basic research of leptospirosis.

Metabolic disorders after traumatic brain injury: a narrative review of systemic consequences

Traumatic brain injury (TBI) is characterized as a heterogeneous and pathological remodeling of brain physiology because of various external mechanisms, including blows, falls, and rapid acceleration and deceleration of the skull. Its pathophysiology consists of two distinct moments, beginning with a primary lesion resulting from the impact that evolves into a secondary lesion as biochemical and molecular mechanisms are activated. The severity and prognosis after TBI vary widely, depending on factors such as the site of the injury, the patient's premorbid history, and the severity of the injury, and can result in long-term sequelae impacting multiple organs and systems, with a reduction in the life expectancy of these individuals. A relevant point to be investigated is the correlation between metabolic syndrome (MS), defined as the combination of glucose intolerance, dyslipidemia, systemic arterial hypertension (SAH), and acute or chronic coronary heart disease, and the prognosis of these individuals after a TBI. Therefore, this review seeks to verify the correlation between the occurrence of MS in patients who have suffered TBI as a pre-existing comorbidity and whether it develops later, looking for evidence in studies based on animal models and cohort follow-ups of individuals who have suffered TBI in the short and long term to assess the prognosis presented.

Are Animal Models Necessary? Exploring (Dis)advantages and Alternatives

Animal models have been crucial for scientific development, allowing researchers to understand the underlying mechanisms of various human conditions, and are far from becoming obsolete in scientific research. However, the ethics of animal experimentation has been a prevalent question between both experts and nonexperts. This essay tackles the advantages and disadvantages of the usage of animal models while delving into new alternatives that have emerged in light of contemporary science.

A stable rat model of high altitude pulmonary edema established by hypobaric hypoxia combined diurnal temperature fluctuation and exercise

Hypobaric hypoxia (HH) is regarded as the main cause of high-altitude pulmonary edema (HAPE), however, the effect of diurnal temperature fluctuation and exercise has been overlooked. The aim of current study was to elucidate the role of diurnal temperature fluctuation and exercise in the development of HAPE and establish a reliable experimental rat model. Male SPF Wistar rats were assigned to control group (1400 m, 25 °C) and five model groups: Model Ⅰ group (6000 m, 25 °C), Model Ⅱ group (6000 m, 2 °C), Model Ⅲ group (6000 m, 12 °C/2 °C light/dark cycle), Model IV group (6000 m, 2 °C, and exercise) and Model V group (6000 m, 12 °C/2 °C light/dark cycle, and exercise). After exposure for 72 h, the blood and lung tissues were collected for further research. The rats in Model I group did not show signs of HAPE. Compared with Model I group, the rats in Model II and Model III groups were suffered from more damage, evidence by enhanced oxidative stress and inflammatory reaction, but still did not show signs of HAPE. Model IV and Model V could induce HAPE, display the obvious pathological changes and edema, more serious oxidative stress and inflammatory reaction in lung tissues, suggesting that the key role of exercise in the development of HAPE. The rats in the Model V group showed the best performance in terms of modeling indicators, indicating that diurnal temperature fluctuation could further aggravate the degree of lung edema. In summary, HH combined with diurnal temperature fluctuation and exercise is a stable and reliable modeling method for HAPE, which can be used for subsequent research on the prevention and treatment of HAPE.

Animal Models of Human Disease 2.0

The use of animal models is crucial for advancing translational research by identifying effective treatment targets and strategies for clinical application in human disease [...].

Biomechanical research using advanced micro-nano devices: In-Vitro cell Characterization focus

BACKGROUND

Cells in the body reside in a dynamic microenvironment subjected to various physical stimuli, where mechanical stimulation plays a crucial role in regulating cellular physiological behaviors and functions.

AIM OF REVIEW

Investigating the mechanisms and interactions of mechanical transmission is essential for understanding the physiological and functional interplay between cells and physical stimuli. Therefore, establishing an in vitro biomechanical stimulation cell culture system holds significant importance for research related to cellular biomechanics.

KEY SCIENTIFIC CONCEPTS OF REVIEW

In this review, we primarily focused on various biomechanically relevant cell culture systems and highlighted the advancements and prospects in their preparation processes. Firstly, we discussed the types and characteristics of biomechanics present in the microenvironment within the human body. Subsequently, we introduced the research progress, working principles, preparation processes, potential advantages, applications, and challenges of various biomechanically relevant in vitro cell culture systems. Additionally, we summarized and categorized currently commercialized biomechanically relevant cell culture systems, offering a comprehensive reference for researchers in related fields.

Dynamic In Vitro PK/PD Infection Models for the Development and Optimisation of Antimicrobial Regimens: A Narrative Review

The antimicrobial concentration-time profile in humans affects antimicrobial activity, and as such, it is critical for preclinical infection models to simulate human-like dynamic concentration-time profiles for maximal translatability. This review discusses the setup, principle, and application of various dynamic in vitro PK/PD infection models commonly used in the development and optimisation of antimicrobial treatment regimens. It covers the commonly used dynamic in vitro infection models, including the one-compartment model, hollow fibre infection model, biofilm model, bladder infection model, and aspergillus infection model. It summarises the mathematical methods for the simulation of the pharmacokinetic profile of single or multiple antimicrobials when using the serial or parallel configurations of in vitro systems. Dynamic in vitro models offer reliable pharmacokinetic/pharmacodynamic data to help define the initial dosing regimens of new antimicrobials that can be developed further in clinical trials. They can also help in the optimisation of dosing regimens for existing antimicrobials, especially in the presence of emerging antimicrobial resistance. In conclusion, dynamic in vitro infection models replicate the interactions that occur between microorganisms and dynamic antimicrobial exposures in the human body to generate data highly predictive of the clinical efficacy. They are particularly useful for the development new treatment strategies against antimicrobial-resistant pathogens.

Preclinical models of bladder cancer: BBN and beyond

Preclinical modelling is a crucial component of advancing the understanding of cancer biology and therapeutic development. Several models exist for understanding the pathobiology of bladder cancer and evaluating therapeutics. N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN)-induced bladder cancer is a commonly used model that recapitulates many of the features of human disease. Particularly in mice, BBN is a preferred laboratory model owing to a high level of reproducibility, high genetic fidelity to the human condition, and its relative ease of use. However, important aspects of the model are often overlooked in laboratory studies. Moreover, the advent of new models has yielded a variety of methodologies that complement the use of BBN. Toxicokinetics, histopathology, molecular genetics and sex can differ between available models and are important factors to consider in bladder cancer modelling.

Advances in, and prospects of, 3D preclinical models for skin drug discovery

The skin has an important role in regulating homeostasis and protecting the body from endogenous and exogenous microenvironments. Although 3D models for drug discovery have been extensively studied, there is a growing demand for more advanced 3D skin models to enhance skin research. The use of these advanced skin models holds promise across domains such as cosmetics, skin disease treatments, and toxicity testing of new therapeutics. Recent advances include the development of skin-on-a-chip, spheroids, reconstructed skin, organoids, and computational approaches, including quantitative structure-activity relationship (QSAR) and quantitative structure-property relationship (QSPR) research. These innovations are bridging the gap between traditional 2D and advanced 3D models, moving progress from research to clinical applications. In this review, we highlight in vitro and computational skin models with advanced drug discovery for skin-related applications.

Sex-specific differences in SLE - Significance in the experimental setting of inflammation and kidney damage in MRL-Faslpr mice

Animal models are an important tool in the research of chronic autoimmune diseases, like systemic lupus erythematosus (SLE). MRL-Faslpr mice are one of different lupus models that develop spontaneously an SLE-like disease with autoantibodies and immune complex deposition that leads into damage of different organs. In contrast to human SLE, both sexes of MRL-Faslpr mice develop a similar autoimmune disease. Due to the sex bias in human and the delayed disease progression in male MRL-Faslpr mice, the majority of studies have been performed in female mice. To determine the suitability of male MRL-Faslpr mice for SLE research, especially with regard to the 3 R-principle and animal welfare, analyses of phenotype, inflammation and damage with focus on kidney and spleen were performed in mice of both sexes. Female mice developed lymphadenopathy and skin lesions earlier as males. At an age of 3.5 month, more immune cells infiltrated kidney and spleen in females compared to males. At the age of 5 months, however, substantially less sex-specific differences were detected. Since other studies have shown differences between both sexes on other manifestations like autoimmune pancreatitis and Sjögren syndrome in MRL-Faslpr mice, the use of male mice as part of 3 R-principle and animal welfare must be carefully considered.

Reliability and relevance of the ES®-RHE model for in vitro skin irritation test application

INTRODUCTION

In vitro methods have been widely used to assess adverse effects. Reconstructed Human Epidermis (RHE) poses as a fascinating test system employed to assess the dermal irritation hazard potential of chemicals. Although several RHE models are reported in the OECD Test Guideline No. 439, the OECD Document No. 220 encourages the scientific community to develop and validate new RHE test systems due to its relevance for socio-economic advancement.

METHODS

Following the criteria documented in the OECD No. 220, a blind study for skin irritation (OECD 439) was conducted employing the Minimum List of Reference Chemicals for Determination of Reproducibility and Predictive Capacity using ES®-RHE. Structural and functional characteristics were assessed alongside the prediction model.

RESULTS

The model has shown reproducibility of optical density and barrier function, similarly to internationally validated methods. Furthermore, it shows the cell layers' development and differentiation ability due to Cytokeratin14, Cytokeratin10, and filaggrin expression. The prediction model resulted in sensitivity, specificity and accuracy rates of 100, 70, and 77 %, respectively.

CONCLUSIONS

The ES®-RHE demonstrated reliability and relevance, with similar structural and functional characteristics comparable to internationally validated models, in addition to the accepted predictive capacity according to OECD required minimum criteria, thus confirming the suitability of the national ES®-RHE in the hazard prediction of dermal irritation based on OECD Test Guideline No. 439.

HCC Model Induced by P53 and Pten Knockout in HBV-Transgenic Mice Mirrors Human HCC at the Transcriptome Level

With a multitude of HCC mouse models available, choosing the one that most closely resembles human HCC can be challenging. This study addresses this gap by conducting a comprehensive transcriptomic similarity analysis of widely used HCC mouse models. In this study, RNA-seq was performed on a model induced by double knockout of P53 and Pten via CRISPR/Cas9 in HBV-transgenic mice. Additionally, RNA-seq data from 2345 various other models induced by different methods were collected from GEO databases. The gene expression profiles, immune microenvironments, and metabolic pathways of these models were compared with those of human HCC. The analysis revealed distinct transcriptomic features among the different models. The HBV + P53&Pten KO model demonstrated the highest overall similarity to human HCC across various parameters. It shared a high degree of overlap in differentially expression genes (DEGs) between tumor and non-tumor tissues with human HCC, exhibited a transcriptome profile and immune cell infiltration pattern closely resembling human HCC, and showed metabolic alterations similar to those in human HCC. Conversely the DEN + CCl4-induced model showed the lowest similarity to human HCC in transcriptome profiles and DEGs and exhibited a distinct immune microenvironment with high NK cell infiltration, with minimal metabolic differences between tumor and non-tumor tissues. This study highlights the importance of selecting appropriate HCC mouse models for research. The HBV + p53&Pten KO model emerged as the most promising due to its remarkable similarity to human HCC across various aspects.

Role of pentoxifylline in neonatal hypoxic ischaemic encephalopathy: a systematic review of animal studies

We systematically reviewed the evidence from animal studies assessing the effects of pentoxifylline on neonatal hypoxic-ischemic encephalopathy (HIE). The PubMed, EMBASE, EMCARE, MEDLINE, Cochrane Library, and Google Scholar databases were searched for randomized and quasi randomized controlled trials (RCTs) in December 2023 to determine the effects of pentoxifylline in animal models of HIE. The quality of the included studies was assessed via the SYRCLE risk of bias (ROB) tool. The certainty of evidence was assessed via the GRADE methodology. All seven included studies (n = 248) involved a rat HIE model in which pentoxifylline (25-150 mg/kg) was administered intraperitoneally. The majority had unclear ROB. All the studies reported a protective effect of pentoxifylline on HIE-induced organ injury. Mortality was comparable at pentoxifylline doses between 25 and 75 mg/kg but higher at 150 mg/kg than in the control group. Three studies reported macroscopic changes in HIE-affected organs. There was a significant reduction in cerebral infarction (40 and 75 mg/kg), hippocampal atrophy, and visible gut injury (60 mg/kg). A significantly lower number of Caspase 3 immunoreactive cells and necrotic cells were observed at the 60 mg/kg dose, whereas the 100 mg/kg dose had a deleterious effect. Three other studies reported significantly reduced levels of proinflammatory markers including IL-6 and TNF-alpha. Current evidence (with low uncertainty) from a rat model suggests that pentoxifylline has the potential to improve mortality and attenuate organ injury following HIE. Adequately powered, well-designed human RCTs are needed to confirm our findings.

Inhalation of itraconazole mitigates bleomycin-induced lung fibrosis via regulating SPP1 and C3 signaling pathway pivotal in the interaction between phagocytic macrophages and diseased fibroblasts

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) stands as a significant contributor to global mortality rates. Presently, there exists a dearth of effective anti-fibrotic treatments for this condition. While itraconazole (ITR) has exhibited potential in mitigating pulmonary fibrosis, its oral administration is hampered by unfavorable pharmacokinetics, which elevate the risk of adverse reactions, thus limiting its clinical utility.

METHODS

An inhalable formulation of ITR were engineered which aimed at enhancing its pulmonary dispersion. First, pharmacokinetics were conducted to investigate the blood concentration and tissue residue of ITR after inhalation administration. In addition, bleomycin induced mouse pulmonary fibrosis model was used to compare the therapeutic effects of ITR administered by inhalation and intragastric administration. Finally, single-cell RNA sequencing (scRNAseq) was used to explore the mechanism of ITR inhalation administration.

RESULTS

We found that a large amount of drugs accumulated in the lung tissue for a long time after inhalation administration, thus maximizing the therapeutic effect of drugs. Inhalation of ITR daily at for 21 days significantly attenuated bleomycin-induced lung fibrosis and inflammation in murine models. Additionally, our findings revealed that ITR inhalation diminished the proportion of diseased fibroblasts while promoting reparative fibroblast populations in the murine model. Furthermore, it effectively reversed the proportion of activated phagocytic macrophages. Mechanistically, ITR inhalation exerted its effects by regulating SPP1 and C3 signaling pathway pivotal in the interaction between phagocytic macrophages and diseased fibroblasts.

CONCLUSIONS

These insights into the molecular mechanisms underlying ITR's therapeutic effects on IPF underscore the favorable pharmacokinetic profile conferred by inhalation, thus presenting a promising formulation poised for clinical translation.

Advancing cancer research through organoid technology

The complexity of tumors and the challenges associated with treatment often stem from the limitations of existing models in accurately replicating authentic tumors. Recently, organoid technology has emerged as an innovative platform for tumor research. This bioengineering approach enables researchers to simulate, in vitro, the interactions between tumors and their microenvironment, thereby enhancing the intricate interplay between tumor cells and their surroundings. Organoids also integrate multidimensional data, providing a novel paradigm for understanding tumor development and progression while facilitating precision therapy. Furthermore, advancements in imaging and genetic editing techniques have significantly augmented the potential of organoids in tumor research. This review explores the application of organoid technology for more precise tumor simulations and its specific contributions to cancer research advancements. Additionally, we discuss the challenges and evolving trends in developing comprehensive tumor models utilizing organoid technology.

Recent advances in environmental toxicology: Exploring gene editing, organ-on-a-chip, chimeric animals, and in silico models

In our daily life, we are exposed to various environmental pollutants in multiple ways. At present, we mainly rely on animal models and two-dimensional cell culture models to evaluate the toxicity of environmental pollutants. Nevertheless, results in animal models do not always apply to humans because of differences between species, while two-dimensional cell culture models cannot replicate the in vivo microenvironments, making it difficult to predict the true toxic response of environmental pollutants in humans. The development of various high-end technologies in recent years has provided new opportunities for environmental toxicology research. The application of these high-end technologies in environmental toxicology can complement the limitations of traditional environmental toxicology screening and more accurately predict the toxicity of environmental pollutants. In this review, we first introduce the advantages and disadvantages of traditional environmental toxicology methods, then review the principles and development of four high-end technologies, such as gene editing, organ-on-a-chip, chimeric animals, and in silico models, summarize their application in toxicity testing, and finally emphasize their importance/potential in environmental toxicology.

Morphological and histological evaluation of the tendon-bone junction in porcine shoulders to create a rotator cuff tear and repair model

BACKGROUND

This study aimed to morphologically and histologically examine whether pig is useful as models for rotator cuff tear (RCT).

METHODS

The morphology of the scapula and humerus bones was evaluated by taking X-ray and three-dimensional computed tomography (3D CT) scans of the right shoulders of five female pigs (age: 4 months). The rotator cuff (RC) footprint at the humeral insertion of these was observed and its shape was measured. Next, they underwent general anesthesia and an acute rotator cuff tear/rotator cuff repair (RCT/RCR) model was created using a deltoid split approach. Four weeks after surgery, the animals were euthanized, the shoulder joints were harvested, and the repaired RC was evaluated by hematoxylin and eosin staining and toluidine blue staining.

RESULTS

The scapula of the pig had a vestigial acromion, in contrast to that in humans. The supraspinatus and infraspinatus tendons were connected so as to overlap each other and attached to the postero-superior part of the greater tuberosity. These tendons were located extra-articularly, separate from the joint capsule. The average antero-posterior length of the foot print was 17.4 ± 0.7 mm on the medial margin and 19.1 ± 2.2 mm on the lateral margin. The maximum medial-to-lateral width of it was 5.1 ± 0.5 mm. In all RCT/RCR models at 4 weeks after surgery, the repaired RC compound tendon was visually confirmed to be continuous with the footprint. Histologically, it was confirmed that regeneration of the four-layer structure of the bone-tendon junction had occurred.

CONCLUSION

Porcine supraspinatus and infraspinatus attachment to the greater tuberosity have a structure similar to that of sheep and dogs, which is advantageous for creating the RCT/RCR model. It might be used for future in vivo studies of shoulder joint diseases.

THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE

Pigs could potentially serve as a viable model for rotator cuff tears.

Mitochondrial dysfunction in psychiatric disorders

Psychiatric disorders are a heterogeneous group of mental disorders with abnormal mental or behavioral patterns, which severely distress or disable affected individuals and can have a grave socioeconomic burden. Growing evidence indicates that mitochondrial function plays an important role in developing psychiatric disorders. This review discusses the neuropsychiatric consequences of mitochondrial abnormalities in both animal models and patients. We also discuss recent studies associated with compromised mitochondrial function in various psychiatric disorders, such as schizophrenia (SCZ), major depressive disorder (MD), and bipolar disorders (BD). These studies employ various approaches including postmortem studies, imaging studies, genetic studies, and induced pluripotent stem cells (iPSCs) studies. We also summarize the evidence from animal models and clinical trials to support mitochondrial function as a potential therapeutic target to treat various psychiatric disorders. This review will contribute to furthering our understanding of the metabolic etiology of various psychiatric disorders, and help guide the development of optimal therapies.

Three-Dimensional Culture of Glioblastoma Cells Using a Tissueoid Cell Culture System

In classical cell culture techniques, cancer cells typically proliferate in a single layer by adhering to the undersurface of laboratory vessels. Consequently, concerns have been raised regarding the fidelity of the morphological and functional characteristics of these cultured cancer cells compared to those of their in vivo counterparts. Our previous studies have investigated various epithelial malignant tumors utilizing the Tissueoid cell culture system, a three-dimensional (3D) cultivation method employing Cellbed-a nonwoven sheet composed of high-purity silica fibers as a scaffold. In this investigation, we have achieved successful 3D culturing of glioblastoma cells (A172 and T98G), which are non-epithelial in nature. As such our focus is to juxtapose their morphological features against that of those cultivated via conventional two-dimensional (2D) methods. Our findings will be elucidated using immunostaining, immunofluorescence staining, and scanning electron microscopy, substantiated with accompanying imaging. Notably, cells cultured in the 3D environment exhibited distinct morphological attributes compared to those of their 2D counterparts, notably featuring pronounced cellular protrusions. We envisage the continued utilization of the 3D culture platform to facilitate diverse avenues of research, encompassing the exploration of novel therapeutic modalities for glioblastoma cells and beyond.

The digital evolution in toxicology: pioneering computational education for emerging challenges

The educational landscape of toxicology is increasingly integrating computational methodologies due to ethical concerns about animal testing and advancements in biotechnological and data analysis tools. This paper examines the evolution and significance of the Toxicology in the 21st century (Tox21) initiative and its impact on computational toxicology education. It contrasts computational toxicology with traditional methods, highlighting the limitations of conventional approaches and the new perspectives offered by computational techniques. The study emphasizes the importance of incorporating computational toxicology into curricula, including case studies that demonstrate how this integration enhances students' problem-solving abilities, real-time data analysis skills, and innovation capabilities. Furthermore, it outlines effective teaching content and methods, including software tools, online resources, and academic literature. The paper also addresses the challenges and limitations faced in this educational shift and explores prospects for advancing computational toxicology education. By documenting these developments, the study aims to clarify the current advancements in toxicology education and the preparedness of students to address global chemical safety challenges with innovative solutions.

Genome-wide pan-GPCR cell libraries accelerate drug discovery

G protein-coupled receptors (GPCRs) are pivotal in mediating diverse physiological and pathological processes, rendering them promising targets for drug discovery. GPCRs account for about 40% of FDA-approved drugs, representing the most successful drug targets. However, only approximately 15% of the 800 human GPCRs are targeted by market drugs, leaving numerous opportunities for drug discovery among the remaining receptors. Cell expression systems play crucial roles in the GPCR drug discovery field, including novel target identification, structural and functional characterization, potential ligand screening, signal pathway elucidation, and drug safety evaluation. Here, we discuss the principles, applications, and limitations of widely used cell expression systems in GPCR-targeted drug discovery, GPCR function investigation, signal pathway characterization, and pharmacological property studies. We also propose three strategies for constructing genome-wide pan-GPCR cell libraries, which will provide a powerful platform for GPCR ligand screening, and facilitate the study of GPCR mechanisms and drug safety evaluation, ultimately accelerating the process of GPCR-targeted drug discovery.

Effects of volume management on free flap perfusion and metabolism in a large animal model study

Free flap failure represents a substantial clinical burden. The role of intraoperative volume management remains controversial, with valid studies lacking. Here, using a large animal model, we investigated the influence of volume management on free flap perfusion and metabolism. Autotransfer of a musculocutaneous gracilis flap was performed on 31 German domestic pigs, with arterial anastomosis and catheterization of the pedicle vein for sequential blood sampling. Flap reperfusion was followed by induction of a hemorrhagic shock with maintenance for 30 min and subsequent circulation stabilization with crystalloid solution, crystalloid solution and catecholamine, autotransfusion or colloidal solution. Flap perfusion and oxygenation were periodically assessed using hyperspectral imaging. Flap metabolism was assessed via periodic blood gas analyses. Hyperspectral imaging revealed no difference in either superficial or deep tissue oxygen saturation, tissue hemoglobin or tissue water content between the test groups at any time point. Blood gas analyses showed that lactate levels were significantly increased in the group that received crystalloid solution and catecholamine, after circulatory stabilization and up to 2 h after. We conclude that, in hemorrhagic shock, volume management impacts acid-base balance in free flaps. Crystalloid solutions with norepinephrine increase lactate levels, yet short-term effects on flap perfusion seem minimal, suggesting that vasopressors are not detrimental.

Status of animal experimentation in nutrition and dietetic research: Policies of 100 leading journals and new approach methodologies

Given animal research is challenged with inadequacies, e.g., animal-to-human knowledge translation, ethical considerations, and cost:benefit, new approach methodologies (NAMs) have been proposed as a replacement. With reference to the field of nutrition and dietetics, our aim was to examine the policies of its leading journals regarding human-based vs. traditional animal-based research; and to explore emerging NAMs that provide alternatives to animal experimentation. We reviewed 100 leading journals from an established database (SCImago Journal Rankings) in the nutrition and dietetics category for the year 2022. Eighty-three journals met the inclusion criteria. NAMs were extracted from a range of established sources. 9.6% (n = 8) of journals state they do not publish animal-based studies; 4.8% (n = 4) consider animal studies with qualifications, whereas the remaining 85.5% (n = 71) publish animal studies without qualification. Across sources, NAMs commonalities were identified including in vitro, in chemico, and in silico methods; and individual and population-based studies. Of leading nutrition/dietetic journals, relatively few have shifted to strictly non-animal methods. Greater attention to the increasing range of NAMs may not only reduce the need for animal research in the field, but may provide superior human-relevant outcomes. Studies are needed to establish their potential superiority.

Engineered Microfibers for Tissue Engineering

Hydrogel microfibers are hydrogel materials engineered into fiber structures. Techniques such as wet spinning, microfluidic spinning, and 3D bioprinting are often used to prepare microfibers due to their ability to precisely control the size, morphology, and structure of the microfibers. Microfibers with different structural morphologies have different functions; they provide a flow-through culture environment for cells to improve viability, and can also be used to induce the differentiation of cells such as skeletal muscle and cardiac muscle cells to eventually form functional organs in vitro through special morphologies. This Review introduces recent advances in microfluidics, 3D bioprinting, and wet spinning in the preparation of microfibers, focusing on the materials and fabrication methods. The applications of microfibers in tissue engineering are highlighted by summarizing their contributions in engineering biomimetic blood vessels, vascularized tissues, bone, heart, pancreas, kidney, liver, and fat. Furthermore, applications of engineered fibers in tissue repair and drug screening are also discussed.

Periodontitis and diabetes in pregnant rats: Maternal-fetal outcomes

Aim

To evaluate the repercussions of periodontitis and diabetes association on rat pregnancy and newborns.

Methods

Diabetes was induced in female Wistar rats 24 h after birth through the administration of Streptozotocin. The diabetic condition of the rats was further confirmed in adulthood. After mating, the pregnant rats were distributed into four experimental groups (n = 12 rats/group): nondiabetic and diabetic with and without periodontitis. Periodontitis was induced by a ligature inserted into the first molar on day 0 of pregnancy. Body weight, water and feed consumption were evaluated weekly, and an oral glucose tolerance test was performed on day 17 of pregnancy. On day 21 of pregnancy, the animals were anesthetized and killed for organ removal. The hemimandibles were collected to analyze alveolar bone loss. Immunological and biochemical parameters were evaluated in the maternal blood samples, and reproductive performance was analyzed. The newborns were weighed, and anomalies evaluated.

Results

The group with diabetes and periodontitis had a greater degree of alveolar bone loss, along with higher relative pancreatic weight, blood glucose levels, triglyceride and inflammatory cytokine levels, hepatic transaminase activity, and embryonic losses. In addition, these newborns had increased body weight, placental weight, a greater number of ossification centers, and a higher rate of visceral and skeletal anomalies.

Conclusion

The combination of maternal diabetes and periodontitis negatively impacts maternal parameters and fetal development. The findings reinforce the importance of maintaining maternal oral health to ensure the general health of the offspring, especially in cases where diabetes is present.

Adipose-Derived Stem Cell Therapy in Spinal Cord Injury

Spinal cord injury (SCI) is a serious condition accompanied by severe adverse events that affect several aspects of the patient's life, such as motor, sensory, and functional impairment. Despite its severe consequences, definitive treatment for these injuries is still missing. Therefore, researchers have focused on developing treatment strategies aimed at ensuring full recovery post-SCI. Accordingly, attention has been drawn toward cellular therapy using mesenchymal stem cells. Considering their wide availability, decreased immunogenicity, wide expansion capacity, and impressive effectiveness in many therapeutic approaches, adipose-derived stem cell (ADSC) injections in SCI cases have been investigated and showed promising results. In this review, SCI pathophysiology and ADSC transplantation benefits are discussed independently, together with SCI animal models and adipose stem cell preparation and application techniques. The mechanisms of healing in an SCI post-ADSC injection, the outcomes of this therapeutic approach, and current clinical trials are also deliberated, in addition to the challenges and future perspectives, aiming to encourage further research in this field.

Ex vivo model of pathological calcification of human aortic valve

The development of drug therapy for the pathological calcification of the aortic valve is still an open issue due to the lack of effective treatment strategies. Currently, the only option for treating this condition is surgical correction and symptom management. The search for models to study the safety and efficacy of anti-calcifying drugs requires them to not only be as close as possible to in vivo conditions, but also to be flexible with regard to the molecular studies that can be applied to them. The ex vivo model has several advantages, including the ability to study the effect of a drug on human cells while preserving the original structure of the valve. This allows for a better understanding of how different cell types interact within the valve, including non-dividing cells. The aim of this study was to develop a reproducible ex vivo calcification model based on valves from patients with calcific aortic stenosis. We aimed to induce spontaneous calcification in valve tissue fragments under osteogenic conditions, and to demonstrate the possibility of significantly suppressing it using a calcification inhibitor. To validate the model, we tested a Notch inhibitor Crenigacestat (LY3039478), which has been previously shown to have an anti-calcifying effect on interstitial cell of the aortic valve. We demonstrate here an approach to testing calcification inhibitors using an ex vivo model of cultured human aortic valve tissue fragments. Thus, we propose that ex vivo models may warrant further investigation for their utility in studying aortic valve disease and performing pre-clinical assessment of drug efficacy.