Scaling up Cryopreservation from Cell Suspensions to Tissues: Challenges and Successes

Abstract

This chapter covers the key physical, biological and practical challenges encountered when developing cryopreservation protocols for larger biological structures and examines areas where cryopreservation has been successful in scaling to larger structures. Results from techniques being used in attempts to overcome these challenges are reviewed together with the indicators for future development that arise from them. The scale-up of cryopreservation to tissues with diverse functions and cell types makes the control of freezing and thawing more challenging. Technology may—or may not—be available depending on the size of the material involved. To meet the challenge there must be innovation in technology, techniques and understanding of damage-limiting strategies. Diversity of cell structure, size, shape and expected function means a similarly diverse response to any imposed cryopreservation conditions and interaction with ice crystals. The increasing diffusion distances involved, and diversity of permeability properties, will affect solutes, solvents, heat and cryoprotectant (CPA) transfer and so add to the diversity of response. Constructing a single protocol for cryopreservation of a larger sample (organoids to whole organs) becomes a formidable challenge.

Finite Element Modeling of Crystallization with Temperature Jump to Improve Cryopreservation of Fish Germ Cells

“…At the same time, it is necessary to take care of the preservation of both the genetic resources of rare, endangered fish species [5][6][7] and the commercial stock of valuable fish species (genetic improvement programs, broodstock management, assistance to species with reproductive problems) [8][9][10]. An effective non-invasive and non-lethal approach to solving this problem is the creation of cryobanks [6,[11][12][13][14]. Such cryobanks are capable of ensuring the safety of cryopreserved germ cell samples without loss of their reproductive qualities for decades, as well as developing selection and breeding direction in marine and freshwater aquaculture farms: sperm saving; simplification of broodstock management; transportation of gametes from different fish farms; and storage of germplasm for genetic selection programs or species conservation.…”