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Research
My research is a collaborative effort with a number
of biologists who are working on several
cryobiological problems. Cryobiology has seen wide
use for efficient preservation of genetic mutants used
in medical research (e.g. mice), assisted reproduction
in humans and animals (e.g. the dairy industry), organ
transplantation (e.g. pancreatic islet cells), and
preservation of endangered species (e.g. the
black-footed ferret). But no, not human heads or
bodies. We are trying to improve existing
cryopreservation protocols and develop new ones for
several cell types. Typically, successful
cryopreservation requires the efficient removal of
cell water and the introduction of cryoprotectants,
e.g. glycerol, without osmotic damage or toxic injury.
Thus it is useful to know the osmotic characteristics,
water permeability (Lp), and solute permeability (Ps)
of target cell membranes in order to model their
response and optimize cryopreservation protocols. My
work deals with understanding passive membrane
transport, the design and analysis of membrane
permeability experiments, and modeling cell responses.
Currently we are working on achieving or improving the cryopreservation of
several species including zebrafish embryos and sperm, coral larvae, monkey
sperm, oyster oocytes, and other marine species of aquaculture interest. We
are also investigating the fundamental mechanisms of cryo damage using mouse
embryos and plant protoplasts. Specifically, what event triggers the generally
lethal formation of intracellular ice? Cells typically do not freeze at their
thermodynamic freezing point, but rather undergo supercooling which can reach
ten’s of degrees C. It is still not understood what drives intracellular
nucleation of this super cooled water.
Current collaborators include Drs. Peter Mazur, University of TN, Knoxville;
Mary Hagedorn, National Zoological Park, Washington, DC, and the Hawaii
Institute of Marine Biology, Oahu, HI; Stuart Meyers, UC Davis, CA; Serean
Adams, Cawthron Institute, New Zealand; and Keisuke Edashige and Magosaburo
Kasai, Kochi University, Japan. My work is funded via subcontracts with my
collaborators who are currently funded by NIH, Friends of the (National) Zoo,
and the Cawthron Institute.
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Recent Publications (Reprints)
Kleinhans FW and Mazur P (2007)
Comparison of actual vs. synthesized ternary phase diagrams for solutes of
cryobiological interest.
Cryobiology 54, 212-222..
Yamaji Y, Valdez DM Jr, Seki S, Yazawa K, Urakawa C, Jin B, Kasai M, Kleinhans FW and Edashige K (2006)
Cryoprotectant Permeability of Aquaporin-3 Expressed in Xenopus Oocytes.
Cryobiology 53 , 258-267.
Guenther JF, Sekia S, Kleinhans FW, Edashige K, Roberts DM, and Mazur P (2006)
Extra- and Intra-Cellular Ice Formation in Stage I and II Xenopus Laevis Oocytes.
Cryobiology 52 , 401-416.
Kleinhans FW, Guenther JF, Roberts DM and Mazur P(2006)
Analysis of Intracellular Ice Nucleation in Xenopus Oocytes by Differential Scanning Calorimetry.
Cryobiology 52 , 128-138.
Hagedorn M, Pan R, Cox EF, Hollingsworth L, Krupp D, Lewis TD, Leong JC, Mazur P, Rall WF, Macfarlane DR,
Fahy G and Kleinhans FW (2006)
Coral Larvae Conservation: Physiology and Reproduction.
Cryobiology 52 , 33-47.
Mazur P, Seki S, Pinn IL, Kleinhans FW and Edashige K (2005)
Extra- and Intracellular Ice Formation in Mouse Oocytes.
Cryobiology 51, 29-53.
Mazur P, Pinn IL, Seki S, Kleinhans FW and Edashige K (2005)
Effects of Hold Time After Extracellular Ice Formation on Intracellular Freezing of Mouse Oocytes.
Cryobiology 51, 235-9.
Hagedorn M, Peterson A, Mazur P and Kleinhans FW (2004)
High Ice Nucleation Temperature of Zebrafish Embryos: Slow-Freezing is not an Option.
Cryobiology 49, 181-189.
Adams SL, Kleinhans FW, Mladenov PV and Hessian
PA (2003)
Membrane Permeability Characteristics and Osmotic
Tolerance Limits of Sea Urchin (Evechinus Chloroticus)
Eggs.
Cryobiology 47, 1-13.
Edashige K, Yamaji Y, Kleinhans FW, and Kasai
M (2003)
Artificial Expression of Aquaporin-3 Improves the
Survival of Mouse Oocytes after Cryopreservation.
Biology of Reproduction 68, 87-94.
Edashige K, Yamaji Y, Kleinhans FW, and Magosaburo
Kasai (2002)
Artificial Expression of Aquaporin-3 Improves the
Survival of Mouse Oocytes after Cryopreservation.
Biology of Reproduction2002, 10.1095/biolreprod.101.002394;
Online.
Hagedorn M, Lance SL, Fonseca D, Kleinhans FW,
Artimov D, Fleischer R, Hoque ATMS, Hamilton M and
Pukazhenthi B (2002)
Altering Fish Embryos with Aquaporin-3: An Essential
Step Toward Successful Cryopreservation.
Biology of Reproduction 67, 961-966.
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