52 effect of carboxylated poly-L-lysine on the post-thaw viability of in vitro-produced XXXX blastocyst.

@entity5731 @entity137 @entity10977 @entity3733 @entity969 @entity291 @entity7055
Recently, there has been development of an antifreeze polyamino acid (carboxylated poly-l-lysine: @entity5731 ) as new cryoprotectants (CPA). This compound counts as amphoteric macromolecular cationic and anionic substituents (polyampholyte) by chemically modifying @entity7055 . In addition, @entity5731 is highly safe and frequently used as a food additive in substitution for other CPA. Other common CPA have high @entity137 and caused physiological damage. In vitro-produced blastocysts were randomly assigned into 3 groups: (1) vitrified embryos with @entity5731 vitrification solution [ @entity5731 -vit-1: 15% @entity5731 +15% @entity10977 (EG); @entity5731 -vit-2: 30% @entity5731 +30% EG+0.5M @entity969 ], (2) vitrified embryos with Vajta et al. solution (Conv-vit-1: 7.5% @entity3733 +7.5% EG; Conv-vit-2: 16.5% @entity3733 +16.5% EG+0.5M @entity969 ), and (3) nonvitrified blastocysts (control). All embryos were frozen by droplet vitrification method. First, the @entity5731 -vitrified embryos were exposed to 5, 10, and 15min in the @entity5731 -vit-1 and then putted for 30 to about 60s in the @entity5731 -vit-2. Then, we compared with each group regarding exposure time of Vit-1. Post-thaw survival rate of each exposure time did not significantly differ among the 3 groups (100 v. 100 v. 100%). However, hatching rate of the 10-min exposure group was higher than that of 5- and 15-min groups (75.0 v. 25.0 v. 66.7; P<0.05). Therefore, we confirmed that exposure time of Vit-1 was exposed for a minimum of 10min. The post-thawed survival rate of each vitrification method was not significantly different between @entity5731 -vit and Conv-vit groups (97.7 v. 86.4%). The total cell numbers of blastocyst did not significantly differ among groups. However, the apoptotic cell numbers of blastocyst was significantly different between the control and Conv-vit groups (0.4  0.6 v. 4.4  3.9; P<0.05) but was not different in control v. @entity5731 -vit (0.4  0.6 v. 2.1  2.4) and Conv-vit v. @entity5731 -vit (4.4  3.9 v. 2.1  2.4). In conclusion, @entity5731 -vit for @entity291 blastocyst could reduce @entity137 and osmotic shock and showed high efficiency on the quality of post-thawed @entity291 blastocysts compared with that of Conv-vit.
