By Sophie Reay,
Historically, preclinical testing on animal models formed a critical step in the drug discovery and development pipeline, to assess the safety and efficacy of investigational drugs before clinical testing in humans. However, owing to problems associated with animal testing including ethical concerns, poor prediction of human responses and high costs, there is now a global movement away from animal testing. In 2022, the Food and Drug Administration (FDA) announced that animal testing is no longer compulsory for safety approval of products (Han, 2023). In April 2025, the FDA released a roadmap outlining a strategic, stepwise approach to phase out animal testing in preclinical safety studies with scientifically validated new approach methodologies (NAMs) (FDA, 2025). Organoids have emerged as a key innovative technology driving this transition. Organoids are self-organised three-dimensional (3D) structures derived from stem cells that display high cellular heterogeneity and emulate the native structure and function of organs in vitro (Park et al., 2024). An extensive range of human tissue-derived organoids have been produced including lung, oesophagus, stomach, kidney, and many more (Cala et al., 2023). In addition to addressing the ethical considerations associated with animal models, organoids offer many other significant advantages. Firstly, they more closely resemble human physiological systems, allowing for better drug screening and disease modelling. Furthermore, organoids can be generated from individual tissues or cells, contributing to the advancement of precision medicine. Experimentation with organoids is also more cost and time efficient, accelerating the clinical translation of novel therapies (Yang et al., 2023).
Following the complex production of organoids, researchers face a critical next step in organoid translational application: ensuring optimal storage and transport conditions to preserve organoid structural and functional integrity. Currently, cryopreservation is considered the gold standard method for long-term preservation of biological samples, typically using liquid nitrogen (-196°C) to halt cellular metabolism (Scientific, 2014). Two commonly used cryopreservation methods include slow freezing and vitrification. While slow freezing involves the addition of a low concentration of cryoprotective agent, such as dimethyl sulfoxide, and a two-step cooling process, vitrification involves gradually adding a high concentration of cryoprotective agent combined with rapid cooling (Han et al., 2024). Although slow freezing is a simple and scalable method, the formation of ice crystals can damage cell membranes consequently leading to cell damage or death. On the other hand, high concentrations of cryoprotective agents in vitrification can induce toxic damage to organoids. The complex structure of organoids can impede the penetration of cryoprotective agents, necessitating longer loading times, which can further compromise viability. Furthermore, within multicellular organoid structures, distinct cell types vary in their osmotic and cryoprotectant tolerances, also complicating cryopreservation strategies (Han et al., 2024). Maintaining the cold chain during organoid transportation is technically challenging and financially expensive (Georgiou et al., 2020; Lee et al., 2024). Therefore, novel preservation methods are needed to improve viability, simplify logistics, reduce costs, and expand global access to organoid technology.
Hypothermic conditions decrease cellular metabolism and slow cell cycle progression. Despite the absence of ultra-low temperatures, hypothermia and associated loss of extracellular matrix support can lead to cellular injuries (Rubinsky, 2003). Hypothermic preservation solutions are designed to minimise the cellular stress responses that can occur at cold temperatures. In 1969, following the development of organ transplantation, the first commercial hypothermic preservation solution coined the “Collins solution” was invented, which enabled kidneys to be stored on ice for approximately 30 hours (Collins;Bravo-Shugarman and Terasaki, 1969). There are now various commercially available preservation solutions including University of Wisconsin solution, Histidine-tryptophan-ketoglutarate and HypoThermosol. Although these preservation solutions can delay apoptosis, their ability to maintain normal cellular function and prolong survival remains limited (Ma et al., 2021). Atelerix is pioneering a shift from cryopreservation to hypothermic hydrogel preservation of biospecimens. Their alginate-based hydrogel technology encapsulates cells and stabilises cell membranes, preventing lipid membrane damage and cell death induced by hypothermia (Marsh, 2024). Atelerix has a wide array of products designed for different biospecimens, with WellReady™ and TissueReady™ being specifically optimised for the ambient storage and shipment of organoids. For example, liver organoids were preserved at 20°C for 5 days using WellReady™. After preservation, organoids were released from the hydrogel and returned to culture for 72 hours. The liver organoids exhibited high viability, maintained their 3D structure and retained their functional capacity, evidenced by expression of hepatic markers and drug-metabolising enzyme (Atelerix, 2025d). DefiniGen, a leading provider of in vitro liver models, collaborated with Atelerix to incorporate Atelerix's WellReady™ preservation technology into their workflow. Cells stored using WellReady™ demonstrated high viability and retained their quality after 72 and 96 hours of encapsulation (Atelerix, 2025b). Moreover, cancer tissues including liver, kidney and oesophagus, were stored at room temperature for 2 days in TissueReady™ PLUS and retained histological integrity. Viable cells were isolated and expanded from cancer tissue preserved for 4-5 days and maintained their phenotype (Atelerix, 2023). Multiple murine tissues including heart, muscle, kidney and liver have been stored in TissueReady™ at 2-8°C for 7 days. Fresh human abdominal skin tissue was also preserved in TissueReady™ for 5 days at room temperature. Haematoxylin and eosin staining demonstrated that all tissue structure and integrity was preserved after the hydrogels were removed from the samples (Atelerix, 2025a). Table 1 highlights the extensive range of organoids that are compatible with Atelerix’s products. Overall, Atelerix’s hypothermic hydrogel technology enables biological samples to be stored or shipped at ambient temperature for extended periods of time, revolutionising biospecimen logistics. This breakthrough eliminates the need for dry ice and specialised containers, reducing both transportation costs and carbon-foot print associated with cryopreservation. Furthermore, simplified logistics reduces the risk of shipping delays and failures. Extended viability at room temperature permits greater flexibility in experimental planning and execution, which is crucial for accommodating the inevitable unexpected changes that arise during research (Marsh, 2024; Sanders, 2024). Importantly, the FDA has issued guidance on novel cell preservation technologies, facilitating wider use of hypothermic hydrogel technology in a clinical setting (Sanders, 2024).
In conclusion, the field of drug development is undergoing a significant paradigm shift, progressively transitioning away from reliance on animal testing. Organoids are emerging as a novel NAM that offer several advantages over animal testing including eliminating ethical concerns associated with animal testing, improved human relevance, personalised medicine applications and enhanced cost and time efficiency. Despite these advantages, challenges remain in the conventional cryopreservation methods used for the storage and transportation of organoids. By leading innovative hydrogel-based hypothermic preservation technology, Atelerix is transforming biospecimen storage and transport, paving the way for broader adoption of organoids in research.
Table 1. Organoids Compatible with Atelerix Products (Atelerix, 2025c)
|
Organoid Type |
Product |
Storage Temperature (°C) |
Storage Time (Days) |
|
Brain |
TissueReady™ |
15-25 (Room Temperature) |
10 |
|
Breast Cancer |
TissueReady™ |
15-25 (Room Temperature) |
5 |
|
Cardiac |
TissueReady™ |
15-25 (Room Temperature) |
5 |
|
CRC |
TissueReady™ |
15-25 (Room Temperature) |
5 |
|
Dermal |
TissueReady™ |
15-25 (Room Temperature) |
7 |
|
Lung Cancer |
TissueReady™ |
15-25 (Room Temperature) |
5 |
|
Liver |
WellReady™ |
15-25 (Room Temperature) |
5 |
References
1. Atelerix (2023) Storage of cancer tissue at room temperature using TissueReady™ PLUS. Available at: https://143938571.fs1.hubspotusercontent-eu1.net/hubfs/143938571/Papers%20and%20Posters/WP-2302-2_TissueReady%20Plus%20White%20Paper%202023.pdf.
2. Atelerix (2025a) Atelerix Data Pack.
3. Atelerix (2025b) Case Study: Enhancing Cell Preservation with Atelerix Technology - A Collaboration with DefiniGen. Available at: https://www.atelerix.co.uk/pages/publications-2?srsltid=AfmBOopGvSVAwK7DRAwDcMTSVh2_YqJ2kNWUaEun_B5eNllFyMgdS3gd#gAV46h6LNO (Accessed: 01.07.2025).
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5. Atelerix (2025d) Hypothermic gel-based technology to preserve tissues and cell models at room temperature (ELRIG 2024). Available at: https://www.atelerix.co.uk/pages/publications-2?srsltid=AfmBOopGvSVAwK7DRAwDcMTSVh2_YqJ2kNWUaEun_B5eNllFyMgdS3gd#gAV46h6LNO (Accessed: 01.07.2025).
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