Test Animals Research Articles

Antidiabetic Effectiveness Test of Bitter melon (Momordica charantia L) Extract Suspension in Male White Mice (Mus musculus)

Diabetes mellitus is a metabolic disorder characterised by the inability of the pancreas to produce the hormone insulin in accordance with the body's requirements. Diabetes mellitus is a lifelong disease and, as yet, there is no cure. The costs associated with diabetes mellitus drugs are currently quite expensive. The utilisation of traditional medicinal practices involving the use of medicinal plants represents an alternative treatment option that employs natural ingredients with minimal side effects. One such example is the use of bitter melon (Momordica charantia L.), which has been demonstrated to possess antidiabetic properties. The objective of this study was to ascertain the antidiabetic efficacy of a bitter melon fruit extract suspension formula. This study employed an experimental methodology, whereby a suspension formulation of bitter melon fruit extract was prepared with three distinct doses. A total of 25 male white mice, induced with alloxan, were selected as test animals and divided into five treatment groups. Group X1 received a dose of 150 mg/kg b.w., Group X2 received a dose of 300 mg/kg b.w., Group X3 received a dose of 450 mg/kg b.w., while the negative control and positive control groups were also included. The data were subsequently analysed using the statistical software package SPSS (version 27), which included tests for normality, homogeneity, one-way ANOVA and the T-test. The findings of this study indicate that the treatment group, which received a suspension of bitter melon fruit extract at a dose of 450 mg/kg bw, exhibited a superior efficacy in reducing blood glucose levels, approaching the level observed in the positive control group.

Influence of the orientation of constructed blood vessels during the 3D printing on the measurement of the pseudo-oxygen saturation of an artificial blood substitute using conventional oxygen sensors: a test series

BackgroundThe development of phantoms to reduce animal testing or to validate new instruments or operation techniques is of increasing importance. For this reason, a blood circulation phantom was developed to test a newly designed retractor system with an integrated oxygen sensor. This phantom was used to evaluate the impact of the 3D printed blood vessel on the measurement of the oxygen saturation.MethodsA solution of nickel sulfate and copper sulfate was prepared as a substitute for real blood. The absorption spectra of these solutions were recorded and compared with those of blood. Subsequently, the oxygen sensor used was calibrated to the blood substitute. Additionally, blood vessels with a simplified geometry were designed and manufactured using inverted vat polymerization and an elastic material (Formlabs Elastic 50 A). To determine the orientation during the printing process, various vessels were printed. Measurements to assess the effects of disturbance (rotation of the vessels during measurements) on the sensor readouts were prepared.ResultsThe impact of disturbances was verified through the rotation of the 3D printed vessels. It was demonstrated that a direct measurement on the disturbances led to outliers and higher values. An optimal orientation was determined to be a lateral placement (90° or 270°) of the sensor. Regarding the orientation of the vessels within the printing space, an orientation of 45° yielded the best results, as the individual layers had the least impact on the light emitted and received by the oxygen sensor.ConclusionThe achieved results demonstrate the influence of the orientation of the vessel during 3D printing as well as the influence of the position of the vessel during the measurement using a conventional oxygen sensor.

Cell Culture Device with a Porous Membrane Electrode for in Situ Electrochemical Measurement of Glucose Uptake and Extracellular pH

Animal testing has been widely used in drug screening. However, the metabolisms of animals are different from those of humans, and thus the failure is discovered at the clinical trial stage. Therefore, reliable tissue models using human cells are needed for drug screening. Microphysiological systems (MPSs) have recently attracted attention for constructing in vivo-like microenvironments. Porous membranes have been used in cell culture devices to fabricate tissue interfaces and functional cell spheroids. Endpoint assays are general for cell evaluation in these systems. For example, labeling of biomarkers and collecting of supernatants are required to evaluate cells. Electrochemical measurements have been used in cell analysis because of their good properties including real-time and in-situ measurements.[1] Previously, we have reported a microfluidic device with a porous membrane electrode for in-situ measurement of nitric oxide released from vascular endothelial cells.[2] In this study, we fabricated an electrochemical device integrated with a porous membrane electrode for in-situ measurement of glucose uptake[3] and extracellular pH. In glucose uptake measurement, cancer cell spheroids were put on the porous membrane electrode, and glucose was measured by enzyme-free method. In extracellular pH measurement, cells were cultured on a polyaniline-modified porous membrane electrode, and the open circuit potential versus a Ag/AgCl reference electrode was monitored.[1] Y. Utagawa et al., Electrochemical Science Advances, 2, 2022, e2100089.[2] Y. Utagawa et al., Analytical Chemistry, 95, 2023, 18158-18165.[3] Y. Utagawa et al., in preparation.

Bio-hydrogel from RGD peptide/chitosan/β-glycerophosphate prevents postoperative wound adhesion

Wound adhesion after any abdominal and gastrointestinal surgery is as high as 90 %, and if the adhesion is severe, it will be fatal. During the operation, various methods are used to avoid the adhesion of organs, such as reducing surgical wound area and using hydrogel products with short gelation time. However, these gels might cause allergy, and the gels are unsuitable for long-lasting recovery processes because the body absorbs them too quickly to avoid sticking. Hence, we developed a long-lasting, temperature-sensitive hydrogel using arginyl-glycyl-aspartic acid to help heal postoperative wounds. The hydrogel formed at 37 °C, degraded in 7 days up to 50 % and provided a practicable anti-adhesion function. As the cell and animal tests indicated, the hydrogel exhibited preferable biocompatibility and was proven to effectively avoid adhesion behavior after abdominal surgery while boosting tissue proliferation; animal experiments have confirmed that hydrogel can effectively avoid adhesion after abdominal surgery and help tissue proliferation. This hydrogel inhibits SMAD, P38, and PI3K pathways by blocking fibrosis cytokines and TGF-β downstream signaling. This TGF-β inhibition promotes histoarchitecture remodeling and reduces cecum tissue fibrosis. Our hydrogel provides a new option for anti-sticking products and can be applied to versatile medical uses in the future.

(Invited) Integrated Electrochemical Devices for Microphysiological Systems

Animal testing has been used for drug screening applications. However, the accuracy of this testing is low due to the difference in metabolization activities between animals and humans. To challenge this issue, there is a growing interest in employing in-vitro assays using human culture cells. These assays involve three-dimensional cell cultures or stimulation within microfluidic devices to replicate in-vivo functions, known as microphysiological systems (MPSs). Also, porous membranes are used to prepare biological interfaces for MPSs, such as gut, lungs, skin, and vasculature, by culturing cells on these membranes.MPSs have been widely evaluated using qPCR and immunostaining methods. However, these methods damage cells, making them unsuitable for real-time or time-course analysis. To challenge this issue, electrochemical (bio)sensors are being explored, as they enable real-time and time-course evaluations of metabolization without cell damage [1].In this study, integrated electrochemical devices have been developed for MPSs. As one example, porous membrane electrodes were fabricated to cultivate cell monolayers and measure cellular activities in situ for MPS applications. Human umbilical vein endothelial cells (HUVECs) were cultured on the membrane as a vascular model and measured the release of nitric oxide (NO) from HUVECs (Fig.: Reprinted with permission from Ref. 2. Copyright 2023 American Chemical Society) [2]. This method allows for the monitoring of short-lifetime molecules like NO because the cells are attached to the electrode.As another example, electrochemiluminescence (ECL) devices were developed for cell analysis [3]. In ECL measurements, electrochemical reactions are converted to optical signals, resulting in successful electrochemical imaging for cell analysis using only a single working electrode. In this study, the ECL devices were applied to visualize cellular respiration activity and cell adhesion.Moving forward, these electrochemical MPS devices hold promise for drug screening and biomedical research, serving as an alternative to animal testing.

Real-time physiological environment emulation for the Istanbul heart ventricular assist device via acausal cardiovascular modeling.

The cost and complexity associated with animal testing are significantly reduced by using mock circulatory loops prior. Novel mock circulatory loops allow us to test biomedical devices preclinically due to their flexibility, scalability, and cost-effectiveness. The presented work describes the development of a hardware-in-the-loop platform to emulate human physiology for the Istanbul Heart (iHeart-II) LVAD. A closed-loop system is developed whereby the effect of the LVAD on the heart and vice versa can be studied. An acausal model of the cardiovascular system is calibrated to emulate advanced-stage heart failure. A new prototype of the iHeart-II LVAD is connected between two air-actuated chambers emulating the left ventricle and aortic chambers with PID controllers tracking numerically modeled pressures from the in silico model. A lead-lag compensator is used to maintain fluid level. Controllers are tuned using nonlinear Hammerstein-Weiner models identified using open-loop data. The iHeart-II LVAD is operated at various speeds in its operational range, and the resulting hemodynamics are visualized in real time. Hemodynamic variables, such as LVAD flow rate, aortic, left ventricular, and pulse pressure, demonstrate trends similar to clinical observations. The iHeart-II LVAD achieves hemodynamic normalization at ~3500 rpm for the emulated condition. A novel evaluation methodology is adopted to study the performance of the iHeart LVAD under advanced-stage heart failure emulation. The models and controllers used in the platform are readily replicable to facilitate VAD research, pedagogy, design, and development.

Impact of microgravity and lunar gravity on murine skeletal and immune systems during space travel

Long-duration spaceflight creates a variety of stresses due to the unique environment, which can lead to compromised functioning of the skeletal and immune systems. However, the mechanisms by which organisms respond to this stress remain unclear. The present study aimed to investigate the impact of three different gravitational loadings (microgravity, 1/6 g [lunar gravity], and 1 g) on the behavior, bone, thymus, and spleen of mice housed for 25–35 days in the International Space Station. The bone density reduction under microgravity was mostly recovered by 1 g but only partially recovered by 1/6 g. Both 1 g and 1/6 g suppressed microgravity-induced changes in some osteoblast and osteoclast marker gene expression. Thymus atrophy induced by microgravity was half recovered by both 1 g and 1/6 g, but gene expression changes were not fully recovered by 1/6 g. While no histological changes were observed due to low gravity, alterations in gene expression were noted in the spleen. We found that in bone and thymus, lunar gravity reduced microgravity-induced histological alterations and partially reversed gene expression changes. This study highlighted organ-specific variations in responsiveness to gravity, serving as an animal test for establishing a molecular-level gravity threshold for maintaining a healthy state during future spaceflight.

Creation of aortic regurgitation model on isolated porcine heart and aortic valve-sparing root replacement using a new device for aortic valve cusps positioning

Valve-sparing surgery in ascending aortic and root aneurysms combined with aortic regurgitation (AR) is a relevant and actively developing trend. The ways to improve these operations are the development of new devices to simplify and standardize valve-sparing procedures using animal models and testing in experiment. Objective. To review experimental methods of aortic root aneurysm and AR modeling, as well as devices simplifying aortic valve-sparing root replacement, including a new device for positioning of aortic valve (AV) cusps during valve-sparing root replacement with AV reimplantation (David procedure), which we have developed. Materials and methods. The components of the developed device were manufactured by three-dimensional printing with preliminary modeling in the parametric environment of computer-aided design with the open source code FreeCAD 0.20.1. The possibility of David procedure on the isolated swine aortic root in the experiment using the new device was evaluated. Results. During the experiments we performed aortic root replacement with AV reimplantation on the isolated porcine aortic root. We noted that the developed device provides good exposure of the surgical correction zone and reduces the probability of damage to the aortic root structures, especially to the AV cusps, in the process of reimplantation. The device eliminates the necessity to use assistants during the main stage of intervention, which reduces the probability of operator-associated complications. Conclusion. Standardization and simplification of reimplantation of AV cusps into the vascular graft during aortic root replacement with the help of the device developed by us is achieved by performing trial positioning of AV cusps and hydraulic tests at different positions of the cusps, which simplifies the search for the optimal point of coaptation and allows to keep the found best position of the cusps until their anchoring inside the graft. The directions of further research are improvement of the design of the developed device, experimental studies with evaluation of the result of valve-sparing surgery under conditions of pulsating fluid flow, testing of the technology on large laboratory animals.

Development of hybrid models by the integration of the read-across hypothesis with the QSAR framework for the assessment of developmental and reproductive toxicity (DART) tested according to OECD TG 414

The governing laws mandate animal testing guidelines (TG) to assess the developmental and reproductive toxicity (DART) potential of new and current chemical compounds for the categorization, hazard identification, and labeling. In silico modeling has evolved as a promising, economical, and animal-friendly technique for assessing a chemical's potential for DART testing. The complexity of the endpoint has presented a problem for Quantitative Structure-Activity Relationship (QSAR) model developers as various facets of the chemical have to be appropriately analyzed to predict the DART. For the next-generation risk assessment (NGRA) studies, researchers and governing bodies are exploring various new approach methodologies (NAMs) integrated to address complex endpoints like repeated dose toxicity and DART. We have developed four hybrid computational models for DART studies of rodents and rabbits for their adult and fetal life stages separately. The hybrid models were created by integrating QSAR features with similarities-derived features (obtained from read-across hypotheses). This analysis has identified that this integrated method gives a better statistical quality compared to the traditional QSAR models, and the predictivity and transferability of the model are also enhanced in this new approach.

Advancing alternative methods to reduce animal testing.

Emerging approaches show promise for regulatory use.

Recent Developments in Glioblastoma-On-A-Chip for Advanced Drug Screening Applications.

Glioblastoma (GBM) is an aggressive form of cancer, comprising ≈80% of malignant brain tumors. However, there are no effective treatments for GBM due to its heterogeneity and the presence of the blood-brain barrier (BBB), which restricts the delivery of therapeutics to the brain. Despite in vitro models contributing to the understanding of GBM, conventional 2D models oversimplify the complex tumor microenvironment. Organ-on-a-chip (OoC) models have emerged as promising platforms that recapitulate human tissue physiology, enabling disease modeling, drug screening, and personalized medicine. There is a sudden increase in GBM-on-a-chip models that can significantly advance the knowledge of GBM etiology and revolutionize drug development by reducing animal testing and enhancing translation to the clinic. In this review, an overview of GBM-on-a-chip models and their applications is reported for drug screening and discussed current challenges and potential future directions for GBM-on-a-chip models.

Novel Collagenous Sponge Composites for Osteochondral Regeneration in Rat Knee Models: A Comparative Study of Keratin, Hydroxyapatite, and Combined Treatments.

Thisstudy aims to evaluate the osteoconductive and osteoinductive potential of novel composite collagenous sponges enriched with keratin (K), hydroxyapatite (HA), and their combination (K+HA) for osteochondral regeneration in rat knee models. By examining cell proliferation, mineralization, and vascularization, we aim to determine the regenerative effectiveness of these materials in promoting osteochondral repair, particularly in load-bearing joints like the knee. Addressing the problem of osteochondral defects (OCD), which lead to osteoarthritis-a condition characterized by pain and functional impairment-the hereby research evaluates these biomaterials for their potential to foster bone and cartilage repair, especially in load-bearing joints as the knee. By leveraging an experimental living rat knee model, the effectiveness of these bio-composites is tasted through detailed morphological, biomechanical, and histological analyses. We have employed a rigorous methodology encompassing the selection of biomaterials based on their osteoconductive and osteoinductive traits, their intraosseous application in Wistar rats, and ulterior comprehensive and minutely monitoring. The comparison covers aspects such as cell growth, mean pixel intensity, and other key morphological properties, offering good insights into each material's regenerative capacity. Furthermore, in the present study we have highlighted the fabrication processes of the sponges, including lyophilization and crosslinking, underlining the importance of the biomaterials' physical characteristics in achieving targeted and optimal regenerative outcomes. Preliminary results obtained illustrate the biocompatibility and potential efficacy of these collagen-based composites in promoting bone healing and regeneration, with particular attention being given to the synergistic effects observed in the K+HA combination. This research will contribute to the understanding of material-based regeneration of osteochondral units but also might open avenues for future investigations into the optimization of such therapies for further clinical application. Through a detailed examination of the materials' integration with the test animal bone and cartilaginous tissues and their impact on bone and cartilage healing, this study sets the stage for the advancement of regenerative medicine solutions for OCD and the array of related conditions, offering hope for patients suffering from joint degeneration and injury.

Exploiting blood-based biomarkers to align preclinical models with human traumatic brain injury.

Rodent models are important research tools for studying the pathophysiology of traumatic brain injury (TBI) and developing new therapeutic interventions for this devastating neurological disorder. However, the failure rate for the translation of drugs from animal testing to human treatments for TBI is 100%. While there are several potential explanations for this, previous clinical trials have relied on extrapolation from preclinical studies for critical design considerations, including drug dose optimization, post-injury drug treatment initiation and duration. Incorporating clinically relevant biomarkers in preclinical studies may provide an opportunity to calibrate preclinical models to identical (or similar) measurements in humans, link to human TBI biomechanics and pathophysiology, and guide therapeutic decisions. To support this translational goal, we conducted a systematic literature review of preclinical TBI studies in rodents measuring blood levels of clinically used GFAP, UCH-L1, NfL, t-Tau, or p-Tau, published in PubMed/EMBASE up to April 10th, 2024. Although many factors influence clinical TBI outcomes, many of those cannot routinely be assessed in rodent studies (e.g., ICP monitoring), thus we focused on blood biomarkers' temporal trajectories and discuss our findings in the context of the latest clinical TBI biomarker data. Out of the 805 original preclinical studies, 74 met the inclusion criteria, with a median quality score of 5 (25th-75th percentiles: 4-7) on the CAMARADES checklist. GFAP was measured in 43 studies, UCH-L1 in 21, NfL in 20, t-Tau in 19, and p-Tau in seven. Data in rodent models indicate that all biomarkers exhibited injury severity-dependent elevations with distinct temporal profiles. GFAP and UCH-L1 peaked within the first day after TBI (30- and 4-fold increases, respectively, in moderate-to-severe TBI versus sham) with the highest levels observed in the contusion TBI model. NfL peaked within days (18-fold increase) and remained elevated up to 6 months post-injury. GFAP and NfL show a pharmacodynamic response in 64.7% and 60%, respectively, of studies evaluating neuroprotective therapies in preclinical models. However, GFAP's rapid decline post-injury may limit its utility for understanding the response to new therapeutics beyond the hyperacute phase after experimental TBI. Furthermore, as in humans, subacute NfL levels inform on chronic white matter loss after TBI. t-Tau and p-Tau levels increased over weeks after TBI (up to 6- and 16-fold, respectively); however, their relationship with underlying neurodegeneration has yet to be addressed. Further investigation into biomarker levels in the subacute and chronic phases after TBI will be needed to fully understand the pathomechanisms underpinning blood biomarkers' trajectories and select the most suitable experimental model to optimally relate preclinical mechanistic studies to clinical observations in humans. This new approach could accelerate the translation of neuroprotective treatments from laboratory experiments to real-world clinical practices.

Evaluation of Antidiabetic Activity of <i>Indigofera prostrate</i> on Normal and Streptozotocin Induced Diabetic Albino Wistar Rats

Background: Diabetes mellitus is an ailment that affects majority of individuals in the world. The objective of the current study is to estimate the antidiabetic effect of methanol extract of Indigofera prostrata whole plant, which is cultivated extensively in India’s arid and also desert regions. Aim: The aim of the current investigation is to estimate the efficacy of methanol extract of I. prostrata (MEIP) to prevent streptozotocin-induced diabetes mellitus in albino wistar strain rats. Methods: In current examination, methanol extracts of the whole plant of I. prostrata with the doses of 250 and 500mg/kg/b.wt (body weight) are administered through oral route to the streptozotocin made diabetic animals where n=6. We evaluated the differences in water intake, intake of food, glucose in fasting, weight of body and also the oral glucose tolerance test. When extract of I. prostrata was used for evaluating the (OGTT) Oral Glucose Tolerance Test for diabetic animals, levels of glucose were found to be pointedly lower when administered with 500 mg/kg b.wt as associated to the control group. I. prostrata had specifically reduced the elevated levels of glucose in diabetic rats. I. prostrata is a vital alternative source for managing blood glucose levels in diabetes mellitus that have increased during the condition and need to be further reduced by oral medications that cause hypoglycemia. Biochemical parameters were estimated as a part of the investigation. Results: The results demonstrated that the dried methanol extract of I. prostrata (250 mg/kg/bwt and 500 mg/kg/bwt) considerably declined the levels of blood glucose during the treatment period when compared to glibenclamide (10mg/kg), enhanced the metabolism, improved the health of animals and also enhanced the oral glucose tolerance test. Conclusion: As a result, we can conclude that the whole plant of I. prostrata methanol extract contains antidiabetic activity.

Hematologic and biochemical reference values for anesthetized juvenile German crossbred farm pigs

Juvenile crossbred pigs are widely used for acute and chronic animal testing due to their anatomical and physiological resemblance to humans. They are particularly prevalent in preclinical cardiovascular research, including studies investigating extracorporeal resuscitation and mechanical circulatory support devices. However, the availability of comprehensive laboratory reference values is limited. In a single-center study at the University Medical Center Freiburg, Germany, the hematologic and biochemical laboratory values of anesthetized healthy juvenile German crossbred farm pigs were determined. Blood samples were collected at the beginning of surgical procedures, either arterially or venously. Females and males were compared, and correlation with body weight was assessed. In total, 268 animals (weight 57.8 ± 12.4 kg) were included, thereof 180 castrated males (55.2 ± 7.7 kg) and 79 females (63.6 ± 18.3 kg). There were significant differences between males and females in 11 of 45 parameters and a moderate correlation between body weight and creatinine (R = 0.41, p < 0.001). The reference intervals and insights into sex and body weight correlations enhance the utility of healthy juvenile German crossbred farm pigs in translational research, providing a robust reference for future studies.

A Retrospective Report of Carprofen Administration as Post-Operative Analgesia Reveals Negative Effects of Recommended Doses.

Effective pain management in laboratory animals is crucial for both animal welfare and the reliability of scientific research. We retrospectively examined the effects of carprofen as post-operative analgesia in Sprague Dawley rats following stereotactic surgery. Our data indicate that administering carprofen twice daily (5 mg/kg), as currently recommended by Die Gesellschaft für Versuchstierkunde/Society for Laboratory Animal Science (GV-SOLAS), led to adverse effects such as reduced food and water intake, disrupted fecal excretion, and abdominal bloating consistent with peritonitis. Continued administration exacerbated these symptoms, with post-mortem findings of intestinal obstructions and ulcers. However, when the frequency was reduced to once daily, such adverse symptoms were not observed. These results are based on incidental data collected from various neuroscientific experiments, resulting in small and uneven sample groups across various experimental cohorts. The inherent imbalances in these groups present challenges for statistical interpretation. While the findings suggest that less frequent carprofen use may reduce adverse effects, the surgical interventions and concurrent use of other drugs in these experiments likely exacerbated these outcomes. Further investigation into the interactions between carprofen, surgical stress, and other perioperative factors is needed to refine analgesia protocols in laboratory animals. Despite these limitations, these observations contribute to understanding analgesia protocols and may assist in improving animal welfare practices.

A novel stent flow chamber system demonstrates reduced thrombogenicity of bioresorbable magnesium scaffolds

Coronary artery disease (CAD) is characterized by narrowing and subsequent blockade of coronary arteries, and imposes a significant health and economic burden. Stent and scaffold devices are introduced in advanced CAD to improve vascular stability and restore blood flow. Although in vitro flow systems like the Chandler loop have been developed to enhance the understanding of interactions between device materials, their coatings, and vascular cells, imaging-based in vitro analysis of device performance is limited. In this study, we established a novel stent flow chamber system designed to assess the thrombogenicity of bioresorbable magnesium scaffold (RMS) and stent materials in vitro. Additionally, we compared the thrombogenicity – an important clinical parameter in stent performance – of the Magmaris-316 L stainless steel stent with its predecessors, Magmaris RMS and a prototype of the third-generation RMS (DREAMS 3G). Analysis of platelet adhesion and coverage of the different devices under flow conditions demonstrated that the Magmaris RMS exhibits reduced thrombogenicity compared to the Magmaris-316 L stainless steel stent. Moreover, thrombogenicity of the DREAMS 3G prototype, composed of BIOmag material, is further decreased compared to its predecessors. The observed reduction in thrombogenicity of the DREAMS 3G prototype in vitro suggests additional improvements in clinical safety and efficacy, highlighting its promise for treating CAD. Future research on this prototype may thus open avenues for analyzing other blood components and patient-derived endothelial cells. In line with the 3R principles, this approach may also help reduce the need for animal testing.

Analysis of Current Approaches to Monitoring the Content of Depressor Substances

INTRODUCTION. Raw materials of biological origin can contaminate medicines with depressor substances, such as histamine, acetylcholine, bradykinin, serotonin, and prostaglandins. In the Russian Federation, tests for the content of these impurities are conducted in anaesthetised healthy cats in accordance with the General Chapter Test for depressor substances of the State Pharmacopoeia of the Russian Federation. The global trend towards ending animal testing and the search for ways to eliminate animal tests for depressor substances motivate researchers to study international approaches to the determination of histamine-like substances.AIM. This study aimed to analyse Russian and international approaches to the control of biologicals for depressor substances and to consider the applicability of alternative instrument-based physicochemical methods for the determination of histamine-like impurities, with a view to reducing animal testing.DISCUSSION. The rationale for reducing the use of animals as test systems is set forth in Directive 2010/63/EU of the European Parliament and of the Council of 22 September 2010 on the protection of animals used for scientific purposes. In 2023, the European Pharmacopoeia Commission initiated the removal of in vivo tests for histamine-like substances from the European Pharmacopoeia. However, China and India use animal testing as the basic method for assessing the safety of medicines. In the Russian Federation, the control of depressor substances is regulated under General Chapter 1.2.4.0008.18 of the State Pharmacopoeia of the Russian Federation. Since the publication of General Chapter 42-0063-07 Test for histamine in edition XII in 2007, the State Pharmacopoeia of the Russian Federation has included a compendial text providing for a reduction in the number of cats used for testing. At present, Russian scientists are searching for targeted physicochemical and immunochemical methods for the determination of depressor substances. It has been demonstrated that a reasonable approach is to assess the need for testing a particular medicinal product in animals on a case-by-case basis. This approach will help minimise the number of in vivo tests and maintain an adequate quality of medicines at the same time.CONCLUSIONS. Despite the global trend towards ending animal testing, it is still necessary and required to control medicines for the content of depressor substances. Nevertheless, there is no global consensus on the need to use animals for this purpose. The absence of a separate general chapter/monograph, or references to it, will not change the fact that histamine-like substances are controlled worldwide. The decision to exclude in vivo methods from the European Pharmacopoeia necessitates the search for alternative test methods and the implementation of additional manufacturing controls to minimise the contamination risk for finished medicinal products. Studies have shown that high-performance liquid chromatography can determine the content of histamine in a limited amount of a medicinal product.

Money, Mentorship, and Misinformation: Barriers and Facilitators to Veterinarians' Pursuit of Postdoctoral Training in Laboratory Animal Medicine.

Since 2015, it has become progressively more difficult for programs to recruit residents in laboratory animal medicine (LAM). Veterinarians are a necessary part of animal research, and having a shortage in veterinarians trained to work in this field has the potential to negatively impact research progress as well as animal welfare. With a goal to increase recruitment, we performed this study to better understand the barriers and facilitators that veterinarians experience when navigating the decision to pursue postdoctoral training in LAM. To do this, we recruited first-year LAM residents to participate in semistructured interviews, and performed thematic analysis on their responses. Key barriers included participants' awareness of perceived drawbacks of the field, inaccessibility of information about opportunities within the field, and misinformation about animal research both within the veterinary field and society at large. Key facilitators included participants' awareness of perceived benefits of the field, relationships with professionals involved in laboratory animal science, and formative predoctoral clinical experiences. Overall, we found evidence that information flow is particularly important in recruitment, suggesting that future recruitment strategies may want to target improved communication about LAM and animal research in general.

Characterization of Human Melanoma Skin Cancer Models: A step towards Model-Based Melanoma Research

Advancing 3D in vitro human tissue models is crucial for biomedical research and drug development to address the ethical and biological limitations of animal testing. Recently, 3D skin models have proven to be effective for studying serious skin conditions, such as melanoma. For these advanced models to be applicable in preclinical studies, thorough characterization is essential to understand their applicability and limitations.In this study, we used bioimaging and RNA sequencing to assess the architecture and transcriptomic profiles of skin models, including models with melanoma. Our results indicated that these models closely mimicked skin morphology and gene expression patterns. The full-thickness (FT) model shows a superior resemblance to the human skin, particularly in basement membrane formation and cellular interactions.The integrity of the skin-like properties and gene expression signatures of both skin and melanoma cells were preserved upon the integration of melanoma cells, establishing these models as robust platforms for cancer research. The responsiveness of the FT melanoma models to vemurafenib treatment was successfully monitored, demonstrating their validity as a reliable, reproducible, and humane tool for pharmacological testing and drug development. Furthermore, the transcriptomic data showed that skin models with cancer spheroids had upregulated genes linked to aggressive and resilient cancer behavior compared to spheroids alone. This emphasizes the importance of the microenvironment in cancer progression and suggests that 3D skin models can serve to uncover mechanisms and therapeutic targets that are not detectable in simpler systems. Statement of SignificanceThis study introduces advanced, ethically sound skin and melanoma models as alternatives to animal testing in drug discovery. By thoroughly characterizing these models using bioimaging and RNA sequencing, we demonstrate their close resemblance to human skin, particularly in full-thickness models. These models not only replicate the complex cellular interactions and gene expression patterns of human tissue but also maintain robustness after melanoma integration. Our findings highlight the potential of these models in revealing cancer mechanisms and therapeutic targets, offering a significant impact on melanoma research and preclinical testing.