X-Message-Number: 33081
Date: Fri, 26 Nov 2010 23:32:35 -0800 (PST)
From: 
Subject: Successful restoration of function of frozen and thawed isola...


Elami et al used a directional freezing device from Core Dynamics (see below). 
The full research report stated concern over cryoprotectant toxicity. Perhaps 
somebody might wish to have a talk with them about donating some vitrification 
solution for their use.

J Thorac Cardiovasc Surg. 2008 Mar;135(3):666-72, 672.e1.
Successful restoration of function of frozen and thawed isolated rat hearts.

Elami A, Gavish Z, Korach A, Houminer E, Schneider A, Schwalb H, Arav A. The 
Department of Cardiothoracic Surgery and the Joseph Lunenfeld Cardiac Surgery 
Research Center, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
Abstract

    OBJECTIVE: Long-term organ preservation for transplantation may allow 
    optimal donor-recipient matching with potential reduction in the incidence 
    and severity of rejection. Complete cessation of metabolism may be obtained 
    by freezing. Previous attempts to freeze intact mammalian hearts were 
    limited to -3.6 degrees C, restricting tissue ice content to 34%. We 
    hypothesized that our method will allow recovery of function of the intact 
    rat heart after freezing to -8 degrees C, a temperature at which most of the
    tissue water is frozen.

METHODS: Isolated rat hearts were attached to a Langendorff apparatus. After 
normothermic perfusion, cold cardioplegia was induced followed by perfusion with
a cryoprotecting agent. Hearts were than frozen to -8 degrees C (45 +/- 8 
minutes), thawed, and reperfused (60 minutes).

RESULTS: All frozen and thawed hearts regained normal electric activity. At -8 
degrees C, ice content was 64.36% +/- 13%. The use of 10% ethylene glycol for 
cryoprotection (n = 13) resulted in recovery (mean +/- standard deviation) of 
49.7% +/- 21.8% of +dP/dt, 48.0% +/- 23.5% of -dP/dt, 65.2% +/- 30.8% of 
coronary flow, and 50.4% +/- 23.9% of left ventricular developed pressure. 
Hearts in this group (n = 4) maintained 81.3% +/- 10% viability compared with 
69.3% +/- 14% (not significant) in control hearts kept at 0 degrees C for the 
same duration. Energy stores, represented by adenosine triphosphate and 
phosphocreatine, were depleted to 12.2 +/- 6.1 micromol/g dry weight and 22.5 
+/- 6.4 micromol/g dry weight, respectively, compared with 19.0 +/- 2.5 
micromol/g dry weight and 36.6 +/- 3.0 micromol/g dry weight, respectively (P < 
.05) in the control hearts. The integrity of muscle fibers and intracellular 
organelles after thawing and reperfusion was demonstrated by electron 
microscopy.

CONCLUSION: We demonstrate for the first time the feasibility of functional 
recovery after freezing and thawing of the isolated rat heart while maintaining 
structural integrity and viability.
PMID: 18329491

____________________________________________


Directional freezing does not use a varying magnetic field to suppress the 
formation of large ice crystals. I wonder whether there might not be a synergism
between these two technologies.

http://www.coredynamics.com/

Cell Preservation
using Core Dynamics' Cryopreservation Technologies

Freeze dried and reconstituted leukocytes


Core Dynamics is developing new methods for freezing, thawing and freeze-drying 
cells. The company's unique freezing and thawing technology allows precise 
control, and in a repeatable process, with high recovery, survival and function 
of cells after thawing.

Cells, preserved with the Company's technologies and specially developed 
protocols can be stored for long time periods at room temperature and 
subsequently rehydrated with resultant high rates of cell viability and 
functionality. The company's preservation technologies are already providing 
means for cell storage of cell types that are being studied for therapeutic 
purposes.

This breakthrough is based in part on the innovative freezing technology called 
Multi Thermal Gradient (MTGT) freezing developed by the company. This freezing 
method, also known as directional freezing, achieves low temperature freezing 
without the use of glycerol or DMSO, the additives commonly used today to freeze
cells.

Core Dynamics has expanded the scope of its basic directional freezing 
technology to include a number of different freezing methods adapted to 
different materials. The directional freezing, coupled with the Company's 
freeze-drying technology, are making it possible to freeze-dry a variety of cell
types.

Core Dynamics provides companies and institutions the opportunity to collaborate
on the development of cell preservation methods and protocols to suit specific 
cell types.

Company Profile


>From science fiction to science that reads like fiction, the field of 
cryopreservation has captured the imagination of many. We are fascinated by 
natural phenomena such as the wood frog (Rana sylvatica), which can freeze 
during its winter hibernation when 35-45% of the frog's body may turn to ice. 
Or, for example certain, Antarctic fish that thrive in ice water and 
tardigrades, tiny 1mm invertebrates that can freeze in winter and completely dry
out during the summer.

Core Dynamics is a biotechnology company that is stretching the horizons of the 
science of cryopreservation. The company is active in the research and 
development of unique freezing, thawing and freeze drying technologies that are 
being applied in work with cell preservation, blood transfusion, and tissue and 
organ transplantation. The company has developed unique protocols, equipment and
solutions for cryopreservation of cells, of tissues such as osteo-articular 
cartilage and of whole organs.

Core Dynamics hopes to develop additional applications through research 
partnerships involving its advanced cryopreservation technologies.

Core Dynamics' Research and Development center is located in Ness Ziona, Israel,
with a staff of over 30 research scientists and support personnel. Company 
management has wide experience in the fields of medicine, cryopreservation and 
cell biology. The company's commercial offices are located in Rockville, 
Maryland.

Research in Freezing, Thawing and Freeze-Drying

Core Dynamics' research has led to the successful freezing and lyophilization of
white blood cells and stem cells. The ability to preserve and store cells at 
room temperature, thereby negating the logistical problems involved in 
transportation and storage in freezers and liquid nitrogen will open a world of 
possibilities for research and work with many varieties of cells.

Applying the company's MTG freezing technology and freezing protocols to 
cartilage has led to the successful long term preservation of osteo-articular 
allograft plugs. In a series of clinical trials over the past year preserved 
plugs have been transplanted in patients suffering from cartilage damage in the 
knee.

In the area of whole organs Core Dynamics has successfully transplanted frozen 
thawed ovaries in large animals. In the near future this technology will be 
applied to human ovaries for the purpose of fertility preservation in young 
female patients undergoing chemo and radiotherapy.

Core Dynamics is confident that supplies of lyophilized (freeze dried) cells and
preserved tissues and organs screened for contamination will revolutionize the 
field of cell therapy, the blood transfusion and transplantation industries and 
other research involving a wide variety of cells.

__________________________________

Reprod Biomed Online. 2010 Jan;20(1):48-52. Epub 2009 Oct 31.

Ovarian function 6 years after cryopreservation and transplantation of whole 
sheep ovaries.

Arav A, Gavish Z, Elami A, Natan Y, Revel A, Silber S, Gosden RG, Patrizio P. 
Institute of Animal Science, Agricultural Research Organization, Volcani Center,
Bet Dagan, Israel.
Abstract

    Whole ovary cryopreservation and transplantation has been proposed as a 
    method for preserving long-term ovarian function. This work reports ovarian 
    function 6years post transplantation of frozen-thawed whole sheep ovaries. 
    Three 9-month-old Assaf sheep underwent unilateral oophorectomy to provide 
    organs for the experiments. After perfusing with cold University of 
    Wisconsin solution supplemented with 10% dimethyl sulphoxide, ovaries were 
    cryopreserved using unidirectional solidification freezing technology. After
    thawing, ovaries were re-perfused and re-transplanted orthotopically by 
    microvascular re-anastomosis, to the contralateral ovarian pedicle after 
    removing the remaining ovary. Six years following transplantation and after 
    inducing superovulation, the sheep were killed and the ovaries analysed. Two
    ovaries had normal size and shape showing some recent corpora lutea, while 
    the third showed atrophic changes. A total of 36 antral follicles were 
    counted by transillumination and four germinal vesicle oocytes were 
    aspirated and matured in vitro to metaphase II. Serum progesterone 
    concentrations were indicative of ovulatory activity in one of the three 
    sheep. Histological evaluations revealed normal tissue architecture, intact 
    blood vessels and follicles at various stages. Currently, this is the 
    longest recorded ovarian function after cryopreservation and 
    re-transplantation. Cryopreservation of whole ovaries, using directional 
    freezing combined with microvascular anastomosis, is a promising method for 
    preserving long-term reproductive capacity and endocrine function.

Copyright (c) 2009 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All 
rights reserved.
PMID: 20158987

Rejuvenation Res. 2008 Aug;11(4):765-72.
Cryopreservation of whole murine and porcine livers.
Gavish Z, Ben-Haim M, Arav A. Core Dynamics Ltd., Nes Ziona, Israel.
Abstract

    Preservation of vascularized organs, such as the liver, is limited to 24 h 
    before destructive processes disqualify them for transplantation. This 
    narrow window of opportunity prevents the performance of optimal pathogen 
    screening and matching tests and possibly results in the need for 
    retransplantation. Numerous problems are associated with freezing and 
    thawing a whole liver while preserving its viability upon thawing, including
    complicated geometry, poor heat transfer, release of latent heat, and the 
    difficulty of generating a uniform cooling rate. On the basis of our past 
    success with sheep ovaries, we have now applied our novel freezing technique
    to a larger solid organ, the liver. Whole rat and pig livers were frozen 
    and thawed using directional solidification apparatus, and viability of 
    these livers was tested by means of integrity and functionality in vitro and
    in auxiliary liver transplantation. The thawed rat and porcine livers were 
    intact and demonstrated >80% viability. Histology revealed normal 
    architecture. Bile production and blood flow following auxiliary 
    transplantation were normal as well. Our encouraging results in applying 
    this novel cryopreservation technique in rat and pig livers suggest that 
    this method may enable better human organ donor-recipient matching in the 
    future.
PMID: 18729808

Semin Reprod Med. 2009 Nov;27(6):438-42. Epub 2009 Oct 5.

Directional freezing: a solution to the methodological challenges to preserve 
large organs.
Arav A, Natan Y. Animal Science, Beit Dagan, Israel.
Abstract

    Although 60 years have passed since the first successful freezing of cells, 
    whole organ freezing is in its initial phase. Heat and mass transfer has 
    limited the success of large tissue and organ cryopreservation either by 
    slow freezing or vitrification. In this article we discuss the limiting 
    factors for the successful freezing of whole organs, such as homogeneous 
    cooling rate, supercooling, latent heat, and recrystallization. We show how 
    the use of directional freezing technology provides solutions to these 
    problems. Whole ovary cryopreservation and transplantation has been proposed
    as a new method for preserving long-term ovarian function as opposed to 
    ovarian cortical slices. Fertility preservation will benefit from the 
    success of whole ovary freezing and transplantation.
Thieme Medical Publishers.
PMID: 19806511

J Endod. 2010 Aug;36(8):1336-40. Epub 2010 Jun 23.

Effects of cryopreservation of intact teeth on the isolated dental pulp stem 
cells.

Lee SY, Chiang PC, Tsai YH, Tsai SY, Jeng JH, Kawata T, Huang HM. School of 
Dentistry, Taipei Medical University, Taipei, Taiwan.
Abstract

    INTRODUCTION: Human dental pulp stem cells (DPSCs) have been reported to be 
    useful material for future regenerative medicine. Clinically, 
    cryopreservation of intact teeth can successfully preserve the periodontal 
    ligament for future autotransplantation; however, the effects of 
    cryopreservation procedure on the properties of DPSCs are still unclear. The
    aim of this study was to test whether DPSCs isolated from cryopreserved 
    teeth can express stem cell-specific markers.

METHODS: In this study, a novel programmable freezer coupled to a magnetic field
was used to perform the cryopreservation experiments. The tested DPSCs were 
isolated from magnetically cryopreserved and non-cryopreserved fresh teeth with 
an enzyme digestion procedure. The success rate of isolation, growth curves, 
morphology, stem cell-specific markers, and the differentiation capacity of the 
isolated cells were evaluated and compared.

RESULTS: The isolation rate of dental pulp cells from magnetically cryopreserved
teeth was 73%. After culture for 5 generations, there was no significant 
difference in cell viability between cells isolated from magnetically 
cryopreserved teeth and those isolated from fresh teeth. There were also no 
visible differences between the 2 groups of dental pulp cells in morphology, 
expression of stem cell markers, or osteogenic and adipogenic differentiations.

CONCLUSIONS: The results suggest that cryopreserved whole teeth can be used for 
autotransplantation and provide a viable source of DPSCs.

Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. 
All rights reserved.
PMID: 20647092

Cryobiology. 2010 Aug;61(1):73-8. Epub 2010 May 15.

Cryopreservation of periodontal ligament cells with magnetic field for tooth 
banking.

Kaku M, Kamada H, Kawata T, Koseki H, Abedini S, Kojima S, Motokawa M, Fujita T,
Ohtani J, Tsuka N, Matsuda Y, Sunagawa H, Hernandes RA, Ohwada N, Tanne K. 
Department of Orthodontics and Craniofacial Developmental Biology, Hiroshima 
University Graduate School of Biomedical Science, 1-2-3 Kasumi, Minami-ku, 
Hiroshima 734-8553, Japan.
Abstract

    The purpose of this study was to establish a long-term tooth 
    cryopreservation method that can be used for tooth autotransplantation. 
    Human periodontal ligament (PDL) cells were frozen in 10% dimethyl sulfoxide
    (Me(2)SO) using a programmed freezer with a magnetic field. Cells were 
    cryopreserved for 7 days at -150 degrees C. Immediately after thawing, the 
    number of surviving cells was counted and the cells were cultured; cultured 
    cells were examined after 48 h. Results indicated that a 0.01 mT of a 
    magnetic field, a 15-min hold-time, and a plunging temperature of -30 
    degrees C led to the greatest survival rate of PDL cells. Based on these 
    findings, whole teeth were cryopreserved under the same conditions for 1 
    year. The organ culture revealed that the PDL cells of cryopreserved tooth 
    with a magnetic field could proliferate as much as a fresh tooth, although 
    the cells did not appear in the cryopreserved tooth without a magnetic 
    field. Histological examination and the transmission electron microscopic 
    image of cryopreserved tooth with a magnetic field did not show any 
    destruction of cryopreserved cells. In contrast, severe cell damage was seen
    in cells frozen without a magnetic field. These results indicated that a 
    magnetic field programmed freezer is available for tooth cryopreservation.
(c) 2010 Elsevier Inc. All rights reserved.
PMID: 20478291

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