• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.3
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• pp.228-238
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• 2005

Purpose: Several cryoprotectants are in use to help the survival of cells during cryopreservation of bone in maxillofacial region. Among them, $Me_2SO$(dimethyl sulfoxide), EG(ethylene glycol), sucrose were used for experimentally created defects with accompanying cryopreserved bone graft in the rabbit model. The aim of this study is to analyze the effect of above mentioned agents on bone formation using histologic and histomorphometrical methods, thus to provide experimental support for clinical application of these agents. Materials and methods: Nine rabbits were used as experimental animals. Surgical defects were created on the distal femoral heads and mesial tibial heads of each animal using trephine drill(5mm diameter and 5mm length). The harvested bones were cryopreserved in $-80^{\circ}C$ refrigerator for one week. The defects were filled with cryopreserved bone with cryoprotectants as experimental groups and cryopreserved bone without cryoprotectant as control. Then, the animals were sacrificed at 1, 2, and 3 weeks after surgery. With Goldner's modified Masson trichrome staining and semiautomatic image analysis system, we observed the change of the cells and bone formation. Results: After bone graft, bone formation and active remodeling process were examined in all experimental groups and the control. But the intensity of such activities of the control were somewhat weaker than that of the experiments. Especially $Me_2SO$+sucrose group was the best in bone formation and bone remodeling. $Me_2SO$ group was more than that of EG group in bone fomation. Sucrose seems to be helpful in survival of the bone cell. Histologic findings showed superior bony quantity and quality in experimental groups than that in control. Conclusions: The data from this study provides the basis for future studies for evaluating the effect of cryoprotectants in the cryopreservation of bone and clinical study for predictable use of these agents.

• Development and Reproduction
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• v.11 no.2
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• pp.79-84
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• 2007

The freezing susceptibilities of two larval stages (D-shaped and umbo) of the pearl oyster (Pinctada fucata martensii) were evaluated by the electron microscopy (light, transmission electron and scanning electron). The morphological shapes were examined from each pre-frozen or frozen-thawed stage of the cryopreserved larvae in liquid nitrogen by using the cryoprotectant, dimethyl sulfoxide ($Me_2SO$) mixed with sucrose. Although a portion of the shell was damaged, the hinge and prodissoconch were intact and clearly visible after preservation in liquid nitrogen. In addition, the cytoplasm of the frozen-thawed larvae maintained the normal organelle integrities, e.g., endoplasmic reticula, lipid droplets, mitochondria, nucleus and microvilli. However, some of the frozen-thawed larvae showed irregularly arranged cilia, rough shell surfaces and round-lumped cilium heads. These results indicate that P. fucata martensii larvae are susceptible to freezing, at least at those two critical developmental stages (D-shaped and umbo), and suggest a new industrial investigation including reduction method of cell injury for preserving microbial starter cultures need to be developed.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.73-73
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• 2003

The present study examined the possibility of long term storage, by cryopreservation in liquid nitrogen, of the sperm of Filefish (Thamnaconus septentrionalis), and the changes in motility, survival rate and ultrastructure of the sperm after freezing and thawing. The sperm was collected by stripping and stored on ice until experiments. For selection of the immobilizing solution, diluted artificial seawater (ASW) of 20, 30 and 40% were tested. The sperm motility was significantly inhibited in 30% ASW, and restored entirely after 100% ASW was added again. Two cryoprotectants, dimethyl sulfoxide ($Me_2$SO) and glycerol, were added to 30% ASW to formulate the extenders at the concentrations between 5 to 20% by volume for freezing. The sperm was diluted at the ratio of 1 :6 with the extenders, inserted into 0.5ml plastic straws and frozen at a freezing rate of $50^{\circ}C$/min to $-100^{\circ}C$ after equilibration for 10 min at room temperature, followed by plunging into liquid nitrogen. The straws were thawed in a $30^{\circ}C$ water bath for 15 sec. The highest post-thawed sperm motility and survival rate were obtained with 5% glycerol Afterward, the effect of different freezing rates was examined using 5% glycerol as a cryoprotectant, and the rate of $20^{circ}C/min to $-80^{\circ}C$ showed the best result Some ultrastructural changes of sperm, such as the detachment of plasmatic and nuclear membranes, destruction of mitochondria, were observed after cryopreservation. Morphological normality of the sperm in 5% glycerol frozen at the ratio of 1$0^{\circ}C$/min to $-80^{\circ}C$ was better than that of others.