Alternative natural and biocompatible, cell cryopreservation media

Make an Enquiry

The invention herein proposed provides an alternative to the current gold standard used, DMSO, which is toxic and compromises cell viability after thawing. Furthermore, it allows cell preservation at higher temperatures.


Long-term preservation of biological material is generally done by cryopreservation at sub-zero temperatures and, consequently, most biological reactions are ceased. The formation of ice crystals during the freezing process occurs with deadly consequences. The only way to inhibit the formation of ice, especially intracellular ice, is through the addition of a high concentration of a special additive called cryoprotectant agent (CPA). This cryopreservation method is called vitrification. The most common CPA is dimethyl sulfoxide (DMSO). However, its toxicity is well known and deleterious effects over stem cells have been reported after being cryopreserved with this CPA.

It has been showed that many animals that can survive extreme thermal amplitudes between winter and summer in their natural habitats, produce certain metabolites that are able to decrease significantly the crystallization temperature of water, avoiding either cell membrane disruption due to the formation of deadly ice crystals but also allowing the cells to overcome the osmotic effects. These metabolites are mostly sugars, organic acids, choline derivatives and polyols, i.e., NADES constituents. So, NADES composed of these metabolites have all the properties to be able to substitute the toxic DMSO for the cryopreservation of cells.

The invention herein proposed provides evidences for that new cryoprotectant agents, based on NADES may enhance the cryopreservation performance for the storage of different cell types at milder temperatures, avoiding the use of cryotanks and significantly reducing the costs of transportation.


The solution is a biocompatible CPA that can be injected together with the cells in the patient, such as any common excipient. Most importantly, with our solution, cells can be stored at -20 ºC., a temperature easily reached in a normal household freezer overcoming the need for specialized and expensive equipment that currently is used to store the cells at -196 ºC., and the cold chain required to transport the cells to the storage facility from there to the end user, who is typically a doctor or veterinarian.


Technology Readiness Level (TRL): 4.


There are several advantages of storing cells with the solution proposed:

  • No need for the use of liquid nitrogen and expensive equipment, reducing costs and carbon footprint.
  • No need for using dry ice when shipping cells, reducing transportation costs and making it much easier to maintain the cold chain.
  • Stem cell therapy becomes virtually available everywhere, opening opportunities in new markets (e.g. veterinary market).
  • This solution will allow stem cell therapy to reach those that would never have access to it, such as developing countries and in natural catastrophe or war scenarios.
  • It does not need to be removed before injection and therefore, reduces the cost of the treatment as it can be directly injected into the patient.
  • There is no risk for side-effects as with DMSO.


Cryoprotectant agent for stem cell therapies.



  • Available for exclusive and non-exclusive licensing
  • Seeking co-development partners to extend the research on other possible combinations, design and prepare in vitro testing for the understanding of the mechanisms of action of the system.


Ana Rita Jesus, Liane Meneses, Ana Rita C. Duarte, Alexandre Paiva, Natural deep eutectic systems, an emerging class of cryoprotectant agents, Cryobiology, DOI: 10.1016/j.cryobiol.2021.05.002

Vânia Castro, Joana M. Silva, Rita Craveiro, Rui L. Reis, Alexandre Paiva, Ana Rita C. Duarte, Natural deep eutectic systems as alternative nontoxic cryoprotective agents”, Cryobiology, June 2018, DOI: 10.1016/j.cryobiol.2018.06.010

NOVA Inventors

Ana Rita Cruz Duarte

Alexandre Paiva

Rita Craveiro


Academic Information | NOVA School of Science and Technology | FCT NOVA