Welcome everybody to today’s interview. The topic today will be “Bridging Science and Ethics: The Evolution of CAM Models, Ethical Standards, and AI Advancements”. Elisa and I are very excited to be speaking with Sarah Barnett from the University of Liverpool today.
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Our authors:
Lead content writer, life science professional, and simply a passionate person about technology in healthcare
Content writer focused on the technological advancements in healthcare such as digital health literacy and telemedicine.
Getting to know Sarah Barnett
Dr. Sarah Barnett, a first-class Biochemistry graduate from the University of Liverpool, completed her PhD in cell signalling and cell imaging in 2015. Her recent postdoctoral research, funded by NC3Rs, focuses on BAP1, a tumor suppressor protein linked to poor patient response in mesotheliomas. Collaborating with Professor Judy Coulson, they developed a novel model for mesothelioma using fertilized hen’s eggs. This model allows the growth of mesothelioma tissue with a blood supply from the egg, providing a platform to test new treatments. The Egg Facility, led by Sarah and Prof Coulson, promotes the use of fertilized hen’s eggs as a rapid and cost-effective in vivo model, potentially reducing reliance on mice in various scientific research areas. The facility offers expertise, training, and equipment for experiments in fields such as angiogenesis and drug toxicity.
Benjamin: Hi Sarah, it’s great to have you here today. Please introduce yourself a bit, and tell us about your background and your role at the University of Liverpool.
Sarah: Hello and thank you for having me. In my current capacity, I oversee operations at the egg facility located at the University of Liverpool. This facility serves as a dedicated laboratory space, providing researchers with access to essential equipment for using the CAM model.
We not only offer training and guidance on protocols and experiment optimization but also extend the option for individuals to engage our services in conducting experiments on their behalf—especially useful for those seeking preliminary data for grant applications. My journey led me to this role after serving as a postdoc in Professor Judy Coulson’s lab, where my involvement in utilizing the CAM model began, contributing to its adaptation for studying mesothelioma, a specific type of cancer.
Did you know?
Mesothelioma is a rare and aggressive form of cancer that primarily affects the mesothelial cells lining the lungs, abdomen, heart, or testicles. It is often linked to asbestos exposure, with symptoms typically manifesting several decades after initial exposure.
Benjamin: That’s very interesting, particularly the setup allowing researchers to use your laboratory. So essentially, you provide them with the necessary equipment?
Sarah: Yes, indeed. We’ve established an incubator system for the process. The eggs require incubation at 37 degrees Celsius with a substantial level of humidity, ideally around 50 to 60%. During the initial three days, they need to be gently rocked, a service our specialized incubators provide. Following this, they’re transferred to a non-rocking incubator for cell implantation. We provide hoods for both general use and for working with human tissue, particularly essential for our work on a PDX model.
Additionally, we manage the egg procurement process. Essentially, our facility offers a convenient space where researchers can leverage the model without the burden of investing in the equipment and consumables required for the experiments.
Benjamin: This makes a lot of sense, yes, and what inspires you to work in that field?
Sarah: It all started with a project in Professor Judy Coulson’s lab, where we were investigating new treatments for mesothelioma. Initially designed to progress from in vitro studies to mouse models, ethical concerns and costs led us to explore alternatives.
Dr. Anne Herman’s talk on the CAM model at an NC3R symposium caught our attention, inspiring us to consider this model instead of mice. This pivotal moment marked the beginning of our journey with the CAM model at Liverpool.
Dr. Anne Herman’s talk on the CAM model at an NC3R symposium caught our attention, inspiring us to consider this model instead of mice. This pivotal moment marked the beginning of our journey with the CAM model at Liverpool.
Dr. Sarah Barnett, University of Liverpool.
CAM Research and CAM Assays
Elisa: Great insights! You’ve touched on the CAM model at Liverpool University. Could you offer a concise overview of the CAM model itself and its importance in biomedical research? Additionally, it would be interesting to explore if there are specific studies or diseases where the CAM model demonstrates notable effectiveness.
Sarah: Yes, the CAM model utilizes fertilized hens’ eggs, where a membrane, known as the CAM, forms around the developing embryo. Positioned just below the eggshell, this highly vascularized and thin layer can be accessed non-invasively by creating a hole in the eggshell. Its rich nutrient and oxygen supply make it an excellent platform for implanting cells or tissue.
Primarily, we focus on studying solid tumor cancers and creating xenografts on the CAM. Additionally, its high vascularity makes it ideal for investigating angiogenesis and testing drugs that disrupt vascularization.
The key advantages for us revolve around cost-effectiveness—it’s remarkably affordable, with low husbandry requirements. The incubator only needs to maintain 37 degrees Celsius with high humidity, and no CO2 is required. Importantly, there’s no need for a Home Office License for up to 14 days, making it a highly advantageous model for our research.
Elisa: Thank you for this interesting overview. But if we compare the CAM model to traditional rodent models, how does it differ, and what are the primary advantages?
Sarah: The primary distinctions lie in the model’s duration. Our model operates within a fourteen-day window, with tumor implantation occurring on day seven and observation concluding by day 14. This rapid time frame allows for efficient experimentation, but it presents challenges for longer treatment windows without a Home Office license. The model’s strengths lie in its cost-effectiveness, minimal husbandry requirements, and ethical considerations, making these key advantages for our research endeavors.
Elisa: While undoubtedly presenting challenges, what would you identify as the primary hurdles in establishing CAM models, and how does your lab navigate and address these challenges?
The model’s strengths lie in its cost-effectiveness, minimal husbandry requirements, and ethical considerations, making these key advantages for our research endeavors.
Dr. Sarah Barnett, University of Liverpool.
Sarah: The main challenges we encounter revolve around seasonal effects; a concern shared with mouse models. In winter, our egg supplier yields fewer fertilized eggs with reduced survival rates—sometimes as low as 50%. To mitigate this, we adjust by ordering more eggs.
Another challenge is contamination; cancer cells thrive in eggs, but so do bacteria and fungi due to the nutritious environment. We take extra precautions to maintain cleanliness in egg handling and incubators to prevent breakouts. While these challenges are akin to those in cell culture, addressing them is part of our day-to-day operations.
Benjamin: How do you address the problem of contamination? I mean, you mentioned already keeping everything very clean, but do you also use or introduce for example antibiotics or any other substances that can help you prevent it?
Sarah: We do not introduce antibiotics or antifungal reagents. This precaution is taken to avoid potential hidden infections that could impact results. As the facility manager, we adhere to basic cleaning schedules to maintain a clean environment and minimize the risk of unforeseen influences on experimental outcomes.
Benjamin: Do you use a certain breed of chicks or eggs?
Sarah: Just your normal domestic chicken. There are different types, but we just use brown eggs. You can also use white eggs.
Benjamin: Why do you use brown eggs? Is there any advantage?
Sarah: The distinction I’ve observed between brown and white eggs lies in their shells. White eggs tend to have a softer shell, making them preferable for ex-ovo procedures where the entire content is removed, as they open up more easily. On the other hand, brown eggs have a thicker and harder shell, making them better suited for procedures conducted within the egg, providing greater robustness, and reducing the risk of breakage.
Elisa: Can you discuss or share any recent advancements or modifications in the CAM model that have enhanced its utility in research?
Sarah: Yes. Our main advantage lies in leveraging preclinical imaging, particularly for our interest in preclinical imaging devices designed for mice, such as MRI, bioluminescent imaging, and PET CT.
At our university’s Center for Pre-Clinical Imaging (CPI), which primarily uses rodent models, we’ve adapted these modalities for use with the EGG model. The similarity in size between an egg and a mouse allows us to utilize the same equipment to monitor the effects of drugs on xenografts within the egg, enabling longitudinal observations. Later, we can conduct histology or expression analysis with qPCR.
For bioluminescence, we label cell lines with a reporter, while for human tissue, we utilize PET CT. This ongoing development holds great promise, allowing us to study the impact of drugs on patient tissue samples as they grow within the egg.
3R in Animal Research (Replacement, Reduction, and Refinement)
Benjamin: I’d like to touch upon the principles of the 3Rs in animal research—replacement, reduction, and refinement. How does the CAM model align with these principles in its application?
Sarah: The CAM model serves as a partial replacement for mice, especially in the context of xenograft models. Conducting a xenograft on the CAM offers a more ethically favorable alternative, as it doesn’t necessitate a Home-Office License. Additionally, our engraftment protocol avoids the use of Matrigel, making our approach more animal-free compared to methods that rely on Matrigel, which, in turn, involves animals in its production.
Did you know?
Matrigel is a gelatinous protein mixture derived from the extracellular matrix of Engelbreth-Holm-Swarm (EHS) mouse sarcoma cells. Widely used in cell culture and research, Matrigel mimics the in vivo cellular environment and provides a three-dimensional matrix for various biological assays.
Benjamin: What are the limitations to the CAM model that might necessitate the use of rodent models in certain scenarios?
Sarah: The two main limitations we’ve identified are the restricted time frame—typically treating from day 10 to 14 post-implantation—and the inherent immune suppression during this stage. If long-term treatment or studying interactions with a mature immune system is required, the CAM model is not suitable. In such cases, mice, with their ability for extended treatments and immunocompetent status, become a more suitable alternative.
The CAM model serves as a partial replacement for mice, especially in the context of xenograft models. Conducting a xenograft on the CAM offers a more ethically favorable alternative.
Dr. Sarah Barnett, University of Liverpool.
Benjamin: How do you perceive the balance between the necessity of animal research and ethical considerations? Are the principles of the 3Rs well-established, or do you believe there is still considerable progress to be made? I’m interested in hearing your opinion or insights based on your experience.
Sarah: There’s ample opportunity to explore alternative models ranging from cell lines to advanced systems like spheroids, organoids, and the CAM model. The key to ethical research lies in prioritizing these models before resorting to mice. By relying on a variety of non-animal models, we can potentially eliminate the need for mice, except in cases where studying the immune system is essential.
There’s ample opportunity to explore alternative models ranging from cell lines to advanced systems like spheroids, organoids, and the CAM model. The key to ethical research lies in prioritizing these models before resorting to mice. By relying on a variety of non-animal models, we can potentially eliminate the need for mice, except in cases where studying the immune system is essential.
Dr. Sarah Barnett, University of Liverpool.
However, it’s worth noting that certain animal-free models may fall short in replicating features like vascularization, making the CAM model invaluable for its natural vascularization, especially in tumor engraftment scenarios. While we can significantly reduce reliance on animal models, there remains a space for their judicious use, particularly in protected animal models like rodents.
AI Image Analysis in CAM Research
Benjamin: Fascinating insights. We briefly discussed imaging earlier, and I understand you utilize image analysis software for your CAM research. I’m curious to know how AI image analysis has advanced the capabilities of your CAM research or the CAM model.
Sarah: As mentioned earlier, when it comes to vascularization, AI Image Analysis Software such as the IKOSA software proves invaluable. When engrafting cells, we observe a significant shift in the blood vessel pattern, transitioning from a branching tree to a radial pattern around the tumor, especially evident with our mesothelioma cell lines.
While the visual change is apparent, the software provides quantitative insights, helping us understand specific alterations such as branching or changes in vessel length. The generated mask from the quantification not only facilitates clearer observation but also highlights the substantial differences resulting from cell engraftment, indicating active recruitment of blood vessels by the cells—an intriguing aspect of our research.
When it comes to vascularization, AI Image Analysis Software such as the IKOSA software proves invaluable.
Dr. Sarah Barnett, University of Liverpool.
Benjamin: Does that mean you can make patterns visible that you don’t usually see by eye?
Sarah: Indeed, with subtle changes at such a minute scale, it’s easy to recognize a global shift, but the software significantly enhances visualization by creating a mask. This not only makes the changes more apparent to the eye but also provides precise quantification, helping us understand the specific alterations taking place.
While the visual change is apparent, the software provides quantitative insights, helping us understand specific alterations such as branching or changes in vessel length.
Dr. Sarah Barnett, University of Liverpool.
Benjamin: What insights or conclusions do you gather from the software readout?
Sarah: We analyze various parameters such as the number of branching points, length, total area, and thickness. An intriguing finding was the change in thickness, which wasn’t visually apparent. This discovery added an interesting dimension to our understanding of the vascularization changes observed through the analysis.
Benjamin: As we move forward, how do you envision the evolution of AI image analysis in the realm of CAM research or the broader context of drug target evaluation?
Sarah: We collaborate with researchers in translational and clinical fields who aim to use AI for personalized medicine. The idea is to utilize patient data, such as scans and blood results, to train AI to predict the best treatment route.
Connecting this with the CAM model, one could graft the patient’s tissue onto the CAM and test the predicted treatment, considering the short timeframe before administering it to the patient. While this personalized medicine approach is a futuristic concept, it holds exciting potential for aligning AI predictions with practical treatment testing.
Explore the intricacies of CAM vasculature with the IKOSA CAM Assay Application
Benjamin: That would be the ultimate goal. How do you usually image your tumor models or your CAM models? Is it in-ovo or do you remove the membrane out of the eggshell?
Sarah: Initially, we capture images of the in-ovo model using a microscope, employing brightfield and, for cell lines, fluorescence with markers like GFP. This not only enhances visualization but also allows tracking of cell distribution beyond the xenograft. Following this, we proceed to dissect the model, taking additional microscope images for detailed analysis.
Benjamin: Do you see changes in the tumor microenvironment between for example the CAM and the mouse model or is it quite the same at this early stage?
Sarah: We made a promising discovery with mesothelioma, finding remarkable similarities between the CAM xenografts we generated and those produced in mice. We aim to establish the CAM as an equally effective xenograft model compared to mice, and the encouraging similarity in histology to mouse models supports this endeavor.
We made a promising discovery with mesothelioma, finding remarkable similarities between the CAM xenografts we generated and those produced in mice. We aim to establish the CAM as an equally effective xenograft model compared to mice, and the encouraging similarity in histology to mouse models supports this endeavor.
Dr. Sarah Barnett, University of Liverpool.
Women in Science
Elisa: Thank you for sharing your insights. Shifting gears a bit, I came across data from the UNESCO Institute for Statistics indicating that approximately 30% of the world’s researchers are women. I’d like to discuss this with you. In your experiences, what do you think contributes to this imbalance, and what unique challenges and opportunities do women encounter in the scientific community?
Sarah: Historically, the challenge has been balancing family life with a career in science, although this is gradually evolving. Traditionally, the demands of scientific work, which can extend beyond standard working hours, posed difficulties for individuals with family responsibilities.
However, at the University of Liverpool, I haven’t personally experienced these issues. The university has implemented supportive measures, such as flexible and hybrid working options, to address these challenges. This includes accommodating non-traditional working hours and allowing individuals to balance work with family commitments.
Currently, the university holds a Silver Athena SWAN Award, underscoring its commitment to promoting gender equality and addressing challenges faced by women in academia.
Did you know?
The Silver Athena SWAN Award is a recognition bestowed upon academic institutions and departments in the United Kingdom and Ireland for their commitment to advancing gender equality in higher education and research. The award is part of the Athena SWAN Charter, initiated by the Equality Challenge Unit (now Advance HE) to address gender disparities in academia.
Further, they have initiatives such as “keeping in touch days” for women returning from maternity leave, offering support and special arrangements like grants to facilitate conference attendance, including provisions for partners to assist with childcare.
Elisa: As a female scientist, have any women scientists or researchers been particularly inspirational or influential in shaping your work?
Sarah: I’ve had the fortune of having women in influential positions throughout my career. My PhD supervisor was a woman, and my first postdoc supervisor, Professor Judy Coulson, has been my manager for seven years. Additionally, at the university, our head of institute and head of faculty are both female. We also had a female university vice chancellor from 2015 to 2022, showcasing the presence of successful women in high-ranking positions and serving as inspiring role models.
Try the IKOSA CAM Assay Application now.
Outlook
Elisa: As our conversation comes to a close, from your perspective, what do you find to be the most exciting developments or breakthroughs on the horizon in the CAM research space?
Sarah: For us, the focus is on advancing patient tissue models, particularly PDX models. The aspirational goal is to use these as patient avatars, allowing for personalized medicine by obtaining a biopsy, implanting it in eggs, screening treatments, and leveraging CAM model data to inform clinicians about the most effective options for that specific patient’s cancer—a vision aligned with true personalized medicine.
For us, the focus is on advancing patient tissue models, particularly PDX models. The aspirational goal is to use these as patient avatars, allowing for personalized medicine by obtaining a biopsy, implanting it in eggs, screening treatments, and leveraging CAM model data to inform clinicians about the most effective options for that specific patient’s cancer—a vision aligned with true personalized medicine.
Dr. Sarah Barnett, University of Liverpool.
Elisa: Is there any additional information or insights you’d like to share about your work, your goals, or perhaps a general message to the research community?
Sarah: For me, a key focus is sharing information. We initiated the CAM conference last year, held every two years for CAM model researchers.
However, one challenge lies in the lack of standardized protocols across countries, leading to variations in model timelines. Establishing a universal set of practices would greatly facilitate collaboration and information sharing among researchers using the CAM model.
Elisa: If someone is considering getting involved in CAM model research, reaching out to this platform would be the best course of action, correct?
One challenge lies in the lack of standardized protocols across countries, leading to variations in model timelines. Establishing a universal set of practices would greatly facilitate collaboration and information sharing among researchers using the CAM model.
Dr. Sarah Barnett, University of Liverpool.
Sarah: Yes, a great starting point would be to attend the conference where many individuals are engaged in CAM model research. Alternatively, reaching out to anyone involved, including contacting me, is also a viable option.
Elisa: All right, that concludes our interview for today. Sarah, I appreciate you sharing those intriguing facts and insights—I’ve gained a lot from our conversation. Thank you for dedicating your time and engaging in this discussion. I look forward to our future conversations.
Sarah: Thank you very much for having me.