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Preservation method | Storage temperature | Storage medium | Duration of storage | Advantage | Disadvantage | Reference |
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Domestic freezer | 4°C | Culture medium often without any addition of CPA | 14–28 days | No ice crystal formation, no CPA addition | Short storage period which is insufficient to carry out immunological and biomechanical assays which are to be carried before transplantation, decrease in cellular activity with an increase in time | Bae et al., 2009 [4]
Williams et al., 2003 [5]
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Deep freezer | −80°C | CPA or without CPA | 30–60 days | No complex device required, low running cost | Critical temperature for preservation of the 3D construct and the sensitive cells seeded on it, uncontrolled freezing, ice crystals formation | Bakhach, 2009 [6] |
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Controlled rate freezing | A stepwise method can be up to −150°C | CPAs are added | As long as desired when sample is plunged in LN2 | Low concentration of CPA, cooling is carried out at a constant cooling rate so as to cause minimum damage to the tissue, allows the cells to dehydrate in equilibrium with the partially frozen cryoprotectants and other extra solutions present in the suspension | Optimized protocols required for each biological product, needs a skilled and experienced person to handle the entire process so that cooling is optimized enough to allow water to efflux out from the cell during extracellular ice formation |
Enneking, 1991 [7]
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Liquid nitrogen LN2 | Ultra low temperature −196°C | CPAs are added | As long as desired with reliable LN2 back up | Rapid cooling method, simple handling, mechanically reliable | Risk of contamination via LN2, LN2 is costly; therefore, a high running cost as regular supply of LN2 is required | Salai et al., 1997 [8], Cetinkaya and Arat, 2011 [9] |
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Vapour phase LN2 | Temperature below −150 | CPAs are added | As long as desired with reliable LN2 back up | Eliminate the risk of cross-contamination from other samples and microbes | Vapour phase varies from protocol to protocol and the geometry of the tissue, there is often temperature fluctuation within the vapour phase, volume occupied within the container is nonplanned, regular supply of LN2 is required |
Tissue engineering Clemens van blitterswijk—chapter 13 by Lilia Kuleshova and Dietmar Hutmacher [10] |
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