@techreport{oai:kanazawa-u.repo.nii.ac.jp:00042927,
 month = {Mar},
 note = {赤血球,精液,臓器などに代表される生物体の凍結は,低温化と活性水分の低減による長期保存を目的とするものであり,生命の維持を第一義とする.
生物体には無機塩を溶かした自由水と,タンパク質などの高分子と結びついた結合水が細胞内外のせまい領域に存在しており,このような水分の化学的・物理的拘束性が細胞外での微細氷晶を形成させ,これらが種々の凍結障害をもたらす要因となっている.
本研究は以上のような生物体の凍結および融解の機構を実験的・理論的に追究し,細胞レベルで生ずるミクロ挙動と障害に対して統計的な解釈とともに今後のミクロ速度論を発展させるための基礎を得たものである.
(1)浮遊細胞の凍結の速度論的研究により,細胞内外での氷晶形成のあり方,細胞の脱水・収縮などのミクロ挙動が,膜透過係数の変化や凍害保護物質の影響を含めて明らかにされた.
(2)組織細胞の凍結に対して提示されたモデルのもとでシミュレーションを行い,有限試料におけるミクロ挙動ならびにそれに起因する障害が,伝熱における寸法効果として現れることが明らかにされ,生物組織の凍結保存に対する方向性が示唆された.
(3)以上の速度論的な解析と,コムギのプロトプラスト,イ-スト菌,赤血球を供試した凍結実験とにより,生物細胞の凍結におけるミクロ挙動と膠質的損傷とが関連づけられ,ここでのミクロ速度論を今後の分子レベルの研究に発展させるための基礎が形成された.
(4)凍結細胞の解凍におけるミクロ挙動の観察と,エバンスブルーを試薬とした生残率の測定を行い,浸透圧ストレスや氷晶の粗大化による膜機能の喪失などの障害が確認され,その機序が明らかにされた., During freezing, the extra-and intra-cellular ice formation, osmotic water permeation through cell membrane, deformation of cell and other behaviors occur at microscale and they bring serious injuries connecting to the life-and-death of living cells. These micro behaviors occurred on at least cell size level seem to be due to the physicochemical complexity of biological materials. Water is chemically restrained in the states of aqueous solution and colloidal solution, and those are physically confined in small spaces or compartmentalized by the cross-linked network structures.
Firstly, simplified physicochemical model was proposed and the extra- and intra-cellular ice formation, osmotic water permeation through cell membrane and other microscale behavior durig the freezing of biological cell were discussed as a function of temperature considering the effect of cryoprotectant. Extending the simplified model proposed for the cell element, the freezing of the biological substances was anal yzed to get basic understanding for developing the cryopreservation technique.
Furthermore, the freezing and thawing experiments were conducted to pursue the relation between the micro-behavior of biological cell and the injury during freezing and thawing. As a sample of biological cells, protoplasts isolated from cultured wheat cells were selectively used. As the results of microscopic observation using a cold stage whose cooling and warming velocities were controlled, the recovery of cell by water influx due to osmotic pressure difference, and the fusion of intracellular ice were clarified with warming velocity. The thawing injuries such as rupture and swell of the cells were detected, and it was found that the osmotic stress acting on the cell membrane causes these injuries. The survival of cells were also inspected by dye-exclusion test using Evans Blue. The results suggested the rapid temperature-rising is more harmful for slow-freezed cell, but also useful for rapid-freezed cell in which small ice formed., 研究課題/領域番号:04452146, 研究期間(年度):1992-1994, 出典：「生物体の凍結におけるミクロ挙動と伝熱」研究成果報告書　課題番号04452146
  (KAKEN：科学研究費助成事業データベース（国立情報学研究所）)
　　　本文データは著者版報告書より作成},
 title = {生物体の凍結におけるミクロ挙動と伝熱},
 year = {1995}
}