SILANE-COATED SILICA PARTICLE COLLOID PROCESSING OF HUMAN SPERM

Purpose: The purpose of this study was to determine differences in the quality of human sperm processed through different lots of silane-coa ted silica particle colloid solutions. The objectives were to compare (a) sperm kinematic parameters, (b) the sperm acrosome status, (c) the membrane integrity of the head and tail regions, (d) the DNA normalit y, and (e) the heat-inducible hyperactivation motility after processin g sperm through either a Silane-coated silica particle colloid solutio n, a Percoll solution, or a simple centrifuge sperm wash (control). Me thods: Sperm cells were derived from pooled cryopreserved-thawed speci mens of several donors (n = 10). The pooled sperm were divided and pro cessed through either the centrifuge wash, the 90:47% two-layer Percol l, or one of three lots of silane-coated silica particle colloidal sol utions from three vendors. Aliquots of sperm cells were analysed using the Hamilton-Thom HTM-C motility analyzer for differences in kinemati cs and hyperactivation. Sperm were also analysed for membrane integrit y at both head and tail regions, normal morphology, acrosome status, a nd viability. Sperm undergoing apoptosis were determined wing the acri dine orange stain. Processed sperm were also incubated at 40 degrees C for 4 hr and the quality of the sperm was assessed using the heat-ind uced hyperactivation and motility parameter. Results: The data showed that after sperm processing, the number of sperm recovered was higher for the three lots of colloids (silane-coated silica particle colloid solutions) compared with Percoll processing. Total sperm motility was higher in the colloidal washes compared with the control. There were n o differences in motility between Percoll-and colloid-processed sperm. In contrast, the percentages of sperm exhibiting progressive motility or hyperactivation varied among the different lots of colloid solutio ns. The Percoll wash solution yielded the highest percentage of sperm with intact tail membranes, whereas some lots of colloid solutions dis rupted sperm head membranes. The percentages of sperm undergoing apopt osis varied for the different lots of colloid solutions. There was a m arked increase in hyperactivation associated with one colloid solution after heat induction. Conclusions: The results demonstrated variabili ty in the different lots of silane-coated silica particle colloid solu tions for processing sperm. Each lot of colloid solution excelled at i mproving different sperm parameters. The silane-coated silica particle colloid solutions were shown to be effective in recovering motile spe rm compared with Percoll but the types of motility and sperm quality v aried for the different lots of colloid solutions. Due to the variabil ity in lots of silane-coated silica colloid solutions, reported studie s based on only one lot or one source of colloid solution may be diffi cult to interpret. Furthermore, it may be advantageous to select the b est lot of silane-coated silica particle colloid solution to produce t he highest number of sperm exhibiting the ideal parameters for use in assisted reproduction technologies.