Abstract:
A technique for microencapsulation of bovine spermatozoa has been developed with minimal spermatozoal injury and thus of potential use in artificial insemination. The polymers poly-l-lysine, polyvinylamine and protamine sulfate have proven best for membranes. Encapsulation has been successful with capsules ranging in size from 0.75 to 1.5 mm, and with sperm concentrations from 45 to 180 x 10(6) cells mL-1. Successful extenders include CUE, CAPROGEN, and egg yolk-citrate-glycerol (maximum 10% v/v egg yolk for normal capsular shape). Capsule fragility (ability to rupture under ageing and physical stress) is negatively related to membrane thickness which ranges from 1.92 to 5.32 microns (depending on the concentration of polymer used) and positively related to concentration of sperm encapsulated. Heterospermic studies have shown that encapsulated sperm are capable of fertilization in vivo, but are at a disadvantage to unencapsulated sperm when cows are inseminated at conventional times. Uterine retention of inseminates is favoured by capsules having a \'sticky\' membrane. Using current procedures, preliminary homospermic fertility studies indicate that sperm encapsulated with poly-l-lysine or protamine sulfate may achieve normal fertility.
摘要:
已经开发出一种用于牛精子微囊化的技术,其精子损伤最小,因此在人工授精中具有潜在的用途。聚合物聚-l-赖氨酸,聚乙烯胺和硫酸鱼精蛋白已被证明是最好的膜。胶囊的大小从0.75到1.5毫米不等,已成功封装,和精子浓度从45到180×10(6)细胞mL-1。成功的扩展程序包括CUE、CAPROGEN,和蛋黄-柠檬酸盐-甘油(对于正常囊状,最大10%v/v蛋黄)。胶囊脆性(在老化和物理压力下破裂的能力)与膜厚度呈负相关,膜厚度范围为1.92至5.32微米(取决于所用聚合物的浓度),与包封的精子浓度呈正相关。异精子研究表明,包裹的精子能够在体内受精,但是当奶牛在常规时间授精时,对未包裹的精子不利。具有“粘性”膜的胶囊有利于子宫保留子宫。使用当前程序,初步的同性恋生育力研究表明,用聚赖氨酸或硫酸鱼精蛋白包裹的精子可能达到正常的生育力。