Unravelling the secrets of life in the frozen state

This WRH Research Group operates within our department's Reproductive Medicine theme and is run by Prof Suzannah Williams and Dr Peter Kilbride.

Email Peter Kilbride

The Oxford Cryobiology Group

Why is Cryobiology so important?

Cryobiology is the study of life at low temperatures, encompassing everything from cells response to cold to cryopreservation of ATMPs for cancer treatments and all the biological systems in between. Our primary focus is applying this science to preserve life at ultra-low temperatures through cryopreservation.

Cryopreservation allows cells, tissues and genetic material to be stored indefinitely, playing a vital role in medicine, research and conservation.

From preserving eggs and embryos for IVF to storing stem cells from cord blood, cryopreservation has already transformed healthcare. With breakthroughs in cellular therapies and regenerative medicine, cryobiology is advancing rapidly.

Regenerative medicine involves the development of lab-grown cells, tissues, and potentially organs. Treatments such as retinal organoids for macular degeneration, CAR-t cell therapies for cancer treatments, lab-grown livers for transplants, and heart stem cells for reversing heart attack damage all rely on cryopreservation.

Cryopreservation helps store these therapies, reducing patient wait times, lowering treatment costs for the NHS through large-scale production, and simplifying logistics to make new treatments accessible globally.

Who are we?

The Oxford Cryobiology Group is led by Professor Suzannah Williams and Dr Peter Kilbride, bringing together expertise in fertility preservation, endangered species conservation, cell therapies and cryopreservation for regenerative medicine.

Professor Williams has over 20 years of experience in fertility preservation and restoration, particularly in endangered species. She is the founder of the Rhino Fertility Project and has spearheaded multiple conservation initiatives.

Dr Peter Kilbride has been actively involved in cryopreservation for 14 years. He has extensive experience spanning academia, industry, and the intersection of both, with a particular passion for translating laboratory-based cryobiology solutions into real-world applications. Dr Kilbride is a Governor of the Society of Cryobiology and serves on the Board of the Society of Low Temperature Biology.

The team also includes several MSc and DPhil (PhD) students, leading to a diverse, motivated and growing team.

Our group's research spans from understanding the fundamental mechanisms of cryopreservation to making benchside processes clinically ready, while adapting cryopreservation science to new biological systems. Our expertise covers diverse cell and tissue types, as well as various preservation techniques, with a focus on ovarian tissue preservation, cell therapies, and regenerative medicine. We have a range of collaborations nationally and internationally, both academic and industrial.

What we hope to achieve

Supporting conservation efforts with cryobiology: Preserving the genetic material of endangered species is commonplace to preserve at least some biodiversity. Cold-chain logistics entered the public consciousness with COVID-19 vaccine distribution.
Cryopreservation to span disciplines: The physics of ice formation and structure are defined by the chemical properties of freezing mediums, which are dictated by the biological responses of cell membranes and internal vesicles to low temperatures and their physical effects, and typically targeting temperatures as low as -196°C, where standard engineering approaches are often unsuitable.
Unlock the vast potential of cryopreservation: Cryopreservation is a fascinating and versatile field of science, offering solutions that extend across disciplines and biological systems. At its core, the physics of freezing biological material is universal, meaning advancements in one area can often be applied to many others. This makes cryobiology an exciting and unique field with far-reaching potential.
Our overarching aim: To use cryopreservation to bring translational, transformative, innovations to healthcare and beyond.

Cryobiology is more than just a preservation tool - it's a microcosm of science!

our research focus and expertise

Fertility Preservation for Pre-Pubescent Girls

Chemotherapy can cause premature ovarian failure, and therefore eggs are often frozen before treatment. However, eggs cannot be extracted in children, thereby risking fertility loss in young patients. The freezing of ovarian tissue followed by reimplantation into the patient after chemotherapy is the only option.

However, the current prepubertal ovarian freezing methodology is suboptimal, with reimplanted tissues failing after a few years. We aim to optimize freezing techniques for human prepubertal ovarian tissue. By developing focused freezing techniques, we will enhance prepubertal ovarian tissue survival, restoring the fertility of young cancer patients.

Conservation Through Cryopreservation

Cryopreservation is a critical tool for protecting genetic diversity in endangered species. Projects like the Rhino Fertility Project, led by Prof. Williams, aim to develop tailored and practical cryopreservation techniques for preserving genetic material from thousands of individuals. Maintaining at least some genetic diversity is essential for current and future extinction prevention.

Cold Chain Logistics

Shipping biological materials is a challenge that requires precision and innovation. We’re working on intercontinental shipping of cryopreserved materials, how to simplify and lower the cost, and contributing to international guidelines for these processes.

Translating Research to Practice

Moving breakthrough cell-based medicines from the lab to the real world presents new challenges, including strict traceability, sterility during manufacturing, and issues with novel reagents not yet approved by regulatory agencies like the FDA or EMA.

Scaling up from the lab to manufacturing is complex. Once a therapy has approval, making any changes requires costly and time-consuming re-validations, therefore establishing the most robust cryopreservation strategies early on is key. Our team has experience in this space with ATMPs and continues to contribute to developing practical guidelines and standards, ensuring that cutting-edge research translates effectively into clinical and other real-world settings.

Uncovering mysteries

There is still so much we're yet to discover and resolve in cryobiology such as:

Reducing Environmental Impact

Biobanks and cryopreservation facilities contribute to carbon emissions. The liquid nitrogen needed to keep samples cool is an exceptionally high source of carbon dioxide (CO2) during manufacture and shipping. We need to make cryopreservation more sustainable while continuing to advance science.

Tissues and Organs

While most cell types (at least mammalian) can be cryopreserved, albeit recovery varies between cell types, this is only true when cells are in suspension. Methods to preserve whole organs remain elusive. Organs such as heart or liver transplants, for example, only survive a few hours outside the body. Organs are often sent by private aircraft to an always-on-standby surgical team to ensure they can be used. Not only does this add substantial costs to transplants, but many ‘marginal’ organs (for example, from older donors or remote locations) are rejected for transplant.

Improving transplant rates

If we could cryopreserve organs for just a few days, it’s estimated that the number of available transplant organs could increase 2-3 times, as more "marginal" organs would be usable. This breakthrough could revolutionise transplant medicine by eliminating waiting lists, expanding eligibility, reducing rejection rates (with more time for matching and preparation), and significantly lowering costs.

Cryobiology Beyond Earth

We know tardigrades can endure extreme conditions in space, but how long could bacteria, or even more complex cells, survive in suspended animation on a cold, distant world, waiting to encounter a new sun?

Useful links

Society for cryobiology

The Society for Cryobiology brings together those from the biological, medical and physical sciences who have a common interest in the effect of low temperatures on biological systems.

Visit website

Society for Low Temperature Biology

The SLTB aims to promote research on the effects of low temperatures on various organisms and their cells, tissues, and organs. These studies have applications across numerous scientific fields, including biology, medicine, conservation, and environmental science.

Visit website

Rhino Fertility Project

Prof Suzannah Williams and her research team have begun work to find a new way of saving the Northern White Rhino by using tissue taken from animal ovaries to produce potentially large numbers of eggs in a laboratory setting.

Learn more

The research team

Peter Kilbride

Lead Researcher in Cryobiology

Suzannah Williams

Associate Professor & Senior Research Fellow

Our published work and presentations

Any questions?

Please email if you have any questions on Cryobiology or this team's work. We are always happy to engage with others facing cryobiology challenges—whether through advising, consulting, or full collaborations.