title: Quantification of Intracellular Ice Formation and Recrystallization During Freeze-Thaw Cycles and Their Relationship with the Viability of Pig Iliac Endothelium Cells.
abstract: Quantitative evaluation of the inherent correlation between cell cryoinjuries and intracellular ice formation (IIF) together with recrystallization (IIR) is of primary importance for both optimization of biopreservation and cryotherapy. The objective of this study is to thoroughly explore the roles of IIF on cell viability by using pig iliac endothelium cells (PIECs) as model cells during freezing and thawing. The experimental results indicated that both the probabilities of IIF (PIF) and IIR (PIR) increased along with the increase of cooling rates (p < 0.05) during the freeze-thaw cycles at cooling rates of 40, 60, 80, 100, and 150°C/min and the same warming rates of 100°C/min in phosphate-buffered saline-based solutions with or without 1 M DMSO. Viability evaluation with Hoechst 33342/propidium iodide double staining showed that most of the cells were killed (viability <20%) by the abovementioned freeze-thaw cycles, which indicated that the cooling rates investigated were all too rapid since large amounts of IIF and IIR were introduced. Another interesting phenomenon is that the presence of a low concentration of DMSO (1 M) tends to improve cell viability while increasing the PIF and PIR during freezing/thawing, contrary to the common belief that larger PIF corresponds to greater cryoinjury. This may be attributed to the intrinsic protection effect of DMSO by reduction of solution injury or other potential injuries. These findings may be of potential application value for both cryopreservation and cryosurgery by providing helpful additions to the existing studies on investigation of cryoinjuries of PIECs.
authors.affiliation: 1 Centre for Biomedical Engineering, Department of Electronic Science and Technology, University of Science and Technology of China , Hefei, China .
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Liu
authors.affiliation: 1 Centre for Biomedical Engineering, Department of Electronic Science and Technology, University of Science and Technology of China , Hefei, China .|2 Anhui Provincial Engineering Technology Research Center for Biopreservation and Artificial Organs , Hefei, China .
authors.forename: Gang
authors.initials: G
authors.lastname: Zhao
authors.affiliation: 3 Department of Mechanical Engineering, University of Washington , Seattle, Washington.
authors.forename: Zhiquan
authors.initials: Z
authors.lastname: Shu
authors.affiliation: 1 Centre for Biomedical Engineering, Department of Electronic Science and Technology, University of Science and Technology of China , Hefei, China .
authors.forename: Dan
authors.initials: D
authors.lastname: Niu
authors.affiliation: 1 Centre for Biomedical Engineering, Department of Electronic Science and Technology, University of Science and Technology of China , Hefei, China .|4 Center for Reproductive Medicine, The Affiliated Hospital of Anhui Medical University , Hefei, China .
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: 4 Center for Reproductive Medicine, The Affiliated Hospital of Anhui Medical University , Hefei, China .
authors.forename: Ping
authors.initials: P
authors.lastname: Zhou
authors.affiliation: 4 Center for Reproductive Medicine, The Affiliated Hospital of Anhui Medical University , Hefei, China .
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Cao
authors.affiliation: 2 Anhui Provincial Engineering Technology Research Center for Biopreservation and Artificial Organs , Hefei, China .|3 Department of Mechanical Engineering, University of Washington , Seattle, Washington.
authors.forename: Dayong
authors.initials: D
authors.lastname: Gao
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology*; D003460:Crystallization; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D042783:Endothelial Cells / Q000166:cytology*; D007053:Ice; D013552:Swine
chemical_list: D003451:Cryoprotective Agents; D007053:Ice; D004121:Dimethyl Sulfoxide
keywords: cooling rate; cryopreservation; intracellular and extracellular; pig iliac endothelium cells; recrystallization of intracellular ice