Rewarming strategies for cryopreservation: Technological challenges and opportunities in energy conversion

Cryopreservation of living cells and tissues plays a vital role in biomedical research, clinical applications, biotechnology innovation, the development of new vaccines and drugs, and the conservation of endangered species. While significant technological breakthroughs have been achieved in cooling methods—particularly through vitrification for large tissue and organs—the lack of optimal rewarming technology remains a key obstacle to successful cryopreservation, especially for larger samples such as tissues and organs. The primary challenges during the warming process include non-uniformity heating and insufficient rewarming rates, which can lead to thermal stress-induced structural damage and lethal ice recrystallization, ultimately compromising the integrity and functionality of biological materials. In recent years, various advanced warming techniques have emerged, employing different energy conversion approaches to achieve volumetric heating while minimizing the risk of overheating. These techniques involve thermal, mechanical-thermal, and electromagnetic-thermal energy conversions. However, each method presents its own limitation. This review aims to summarize recent advancements in rewarming technologies for cryopreservation, with a focus on their mechanisms, applications, and the key challenges that must be addressed to enable broader adoption in medical and commercial contexts.