April 24th: a call to action for non-animal research
World Day for Laboratory Animals on April 24th serves as a global reminder of the urgent need to transition away from animal testing in the research programmes of both academia and industry. For decades, animals have been used to model human biology, yet we now know that species-specific differences make many of these tests unreliable. In skin research, traditional models involving rodents, pigs, or synthetic substitutes often fail to replicate the specific complexity and function of human skin. Despite regulatory shifts and growing support for New Approach Methodologies (NAMs), non-animal testing must be scientifically robust, standardized, scalable, and widely adopted to drive real change.
As we reflect on this day, the challenge is no longer about proving that animal testing should be replaced where possible — it is about ensuring viable, human-relevant alternatives, that can not only address ethical concerns, but also offer scientific advantages, are accessible and trusted by regulators, researchers, and other industry stakeholders.
The 3Rs and the ongoing gaps in non-animal skin testing
The principles of replacement, reduction, and refinement (the 3Rs) have long guided ethical improvements in research. While replacing animal testing with more human-relevant models is the ultimate goal, true progress also requires reducing the number of animals used in research and refining methodologies to minimize suffering and improve scientific outcomes. To emphasise this point we noted recent publications on the prosocial behaviours of rodents and their motivation to support and care for injured and disabled animals in their communities, perhaps giving an indication that there has been a dramatic underestimation of the level of suffering animal test subjects can potentially endure.
Adoption of non-animal alternatives across research fields remains inconsistent. Many models that aim to replace animal testing—such as cell-based assays, lab-grown skin constructs or digital simulations—lack key biological components crucial for accurate skin testing. Without minor cell populations (e.g., immune cells), consideration of in vivo mechanical properties, and natural skin architecture, these models often fail to deliver the predictive accuracy required for meaningful research.
One immediate, scalable alternative is the use of explant-based models, which use real human skin to provide physiologically accurate data without relying on live animals. TenSkin™, developed by Ten Bio, is a leading example of how explant models can bridge this gap.
TenSkin™: a human-relevant alternative available today
Unlike traditional models, TenSkin™ preserves the full complexity of native human skin, including its epidermal structure, immune components, and mechanical properties. This makes it a highly predictive and reproducible alternative to animal testing across industries, including pharmaceutical development and transdermal delivery, aesthetic dermatology research, and cosmetics safety and efficacy testing.
Key advantages of TenSkin™:
- Accurate drug penetration data – unlike animal models, which suffer from species-specific differences, TenSkin™ provides results directly relevant to human biology and therefore predictive of clinical responses
- Realistic immune response modelling – essential for studying inflammatory skin diseases, allergies, and irritation responses.
- Reproducible and target population relevant results – biological responses across the globe are not uniform, the ability to select specific tissue donor populations (e.g. age, gender, ethnicity) further enhance research relevance, a major limitation of some non-animal alternatives.
By using the explant-based platform TenSkin™, researchers can transition away from outdated models without sacrificing scientific accuracy or regulatory compliance. This approach aligns with the 3Rs principle, ensuring that animal use is not just reduced but ultimately replaced with a scientifically superior and more human-relative alternative.
The path forward: standardization and industry adoption
For non-animal models to replace animal testing entirely, they must not only be scientifically superior but also widely accepted by regulatory bodies. This requires:
✔ Industry-wide validation – clear frameworks to assess the reproducibility of explant-based models.
✔ Regulatory integration – greater recognition of human-relevant models in preclinical safety testing.
✔ Collaboration across research sectors – to ensure best practice sharing and promotion of global adoption.
Ten Bio is committed to advancing standardization and acceptance of explant-based testing. By engaging with industry partners, researchers, and regulatory bodies, we aim to drive the mainstream adoption of TenSkin™ as a scalable, non-animal alternative for skin research.
TenSkin™ offers an immediate, scientifically robust alternative to animal testing. By fostering collaboration and pushing for industry-wide change, we can accelerate the transition toward a future where human-relevant, reproducible testing becomes the standard in skin research.
As we observe World Day for Laboratory Animals, we must recognize that the tools to replace animal testing already exist—the challenge is to ensure their widespread use. While progress has been made, standardization, validation, and regulatory adoption remain key hurdles.
As we mark World Lab Animal Day, we affirm the progress made. The future of skin testing is here—it is time to leave the animal models behind!
Supporting references
Prosocial behaviors in rodents: Michael J.M. Gachomba, Joan Esteve-Agraz, Cristina Márquez. Neuroscience and Biobehavioral Reviews. 21 June 2024
U.S. Food and Drug Administration. (2025, April 10). FDA announces plan to phase out animal testing requirement for monoclonal antibodies and other drugs. Retrieved from https://www.fda.gov/news-events/press-announcements/fda-announces-plan-phase-out-animal-testing-requirement-monoclonal-antibodies-and-other-drugs
Ten Bio team April 2025.
