Impact of Storage at -80°C on Encapsulated Liver Spheroids After Liquid Nitrogen Storage.
For many bioengineered tissues to have practical clinical application, cryopreservation for use on demand is essential. This study examined different thermal histories on warming and short holding periods at different subzero temperatures on subsequent functional recoveries of alginate encapsulated liver spheroids (ELS) for use in a bioartificial liver device. This mimicked transport at liquid nitrogen (-196°C) or dry ice (∼-80°C) temperatures. Holding at -80°C on warming after -196°C storage resulted in ELS expressing significant (p < 0.001) damage compared with direct thaw from liquid nitrogen, with viable cell number falling from 74.0 ± 8.4 million viable cells/mL without -80°C storage to 1.9 ± 0.6 million viable cells/mL 72 h post-thaw after 8 days storage at -80°C. Even 1 day at -80°C after -196°C storage resulted in lower viability (down 21% 24 h post-thaw), viable cell count (down 29% 24 h post-thaw), glucose, and alpha-1-fetoprotein production (reduced by 59% and 95% 24 h from 1 day post-thaw, respectively). Storage at -80°C was determined to be harmful only during the warming cycle. Chemical measurements of the alginate component of ELS were unchanged by cryogenic exposure in either condition.
Asymptote Ltd., St. John's Innovation Centre, Cambridge, United Kingdom.; UCL Institute for Liver and Digestive Health, Royal Free Hospital Campus, London, United Kingdom.
Peter
P
Kilbride
UCL Institute for Liver and Digestive Health , Royal Free Hospital Campus, London, United Kingdom .
Jordi
J
Gonzalez-Molina
UCL Institute for Liver and Digestive Health, Royal Free Hospital Campus, London, United Kingdom.; UCL Department of Surgery, Royal Free Hospital Campus, London, United Kingdom.
Natasha
N
Maurmann
UCL Institute for Liver and Digestive Health , Royal Free Hospital Campus, London, United Kingdom .
Joana
J
Mendonça da Silva
UCL Institute for Liver and Digestive Health , Royal Free Hospital Campus, London, United Kingdom .
Stephanie
S
Gibbons
UCL Institute for Liver and Digestive Health , Royal Free Hospital Campus, London, United Kingdom .
Clare
C
Selden
UCL Department of Surgery , Royal Free Hospital Campus, London, United Kingdom .
Barry
B
Fuller
Asymptote Ltd. , St. John's Innovation Centre, Cambridge, United Kingdom .
John
J
Morris
HEPG2 cells; alginate encapsulation; bioartificial liver device; cryopreservation; warming rates