Background: The cases with unexplained infertility may have an abnormality in their sperm chromatin structure. Sperm selection methods can be used to separate sperm with low DNA fragmentation. The purpose of this study was to compare the efficacy of physiological intracytoplasmic sperm injection (PICSI) with magneticactivated cell sorting (MACS) in assisted reproductive techniques in cases with unexplained infertility. Methods: The semen samples were collected from couples with unexplained infertility. After semen analysis and sperm DNA fragmentation (SDF) evaluations, samples were prepared with swim-up method. The rates of SDF in different fractions including raw semen (n=20), swim-up (n=20), only motile sperm after swim-up (swim-up selection) (n=20), MACS sperm selection (n=20), only motile sperm after MACS (MACS selection) (n=20), and PICSI sperm selection (n=16) were evaluated. Also, the main sperm characteristics and fine morphology of sperm suspension after MACS were assessed. Statistical analysis was performed using GraphPad Prism. The p<0. 05 was considered statistically significant. Results: DNA fragmentation index (DFI) values in PICSI and MACS groups were significantly reduced as compared to the swim-up group. The rate of this reduction was more pronounced in MACS (58. 20± 13. 02) than PICSI (36. 57± 15. 52) group. Also, our results showed that MACS resulted in decreased sperm motility, with no alteration in their fine morphology. Conclusion: MACS was found to be more efficient in reduction of SDF rates than PICSI. However, none of the sperm selection techniques can not totally eliminated the spermatozoa with DNA fragmentation in the final sperm sample.

Background: The sperm DNA fragmentation index (DFI) is one of the men’ s reproductive health criteria that affects assisted reproductive technique outcomes. Efforts in obtaining high-quality mature sperms seem to be necessary. Advanced sperm selection techniques (including physiological intracytoplasmic sperm injection [PICSI], zeta potential, microfluidic, etc. ) have gained popularity in this regard. Objective: The study aimed to compare the efficacy of zeta potential and PICSI sperm selection in obtaining sperms with better DNA integrity. Materials and Methods: In this cross-sectional study, 48 couples were enrolled where the male partner had increased sperm DFI in his ejaculated sample and the female was in normal reproductive health. For each male partner, the semen sample was processed with zeta potential and PICSI techniques, then the sperm DFI of neat semen was compared to zeta and PICSI samples by the sperm chromatin dispersion test. Results: Data showed that both the zeta potential and PICSI technique decreased sperm DFI in comparison with the neat semen sample (p < 0. 001 for both). In addition, there was a statistically significant difference in sperm DFI between the PICSI and zeta potential samples (p < 0. 01). Conclusion: The current study showed that both zeta potential and PICSI could result in sperm with a lower DFI. However, PICSI seems to be superior to zeta potential in this regard.

Prior to ICSI the cumulus-oophorous-complex of the oocyte is commonly remove with impure animal-derived hyaluronidase of low strength. The lower strength of the enzyme, the high concentration of impurities and the necessity of extensive time-dependent mechanical denudation damages of the oocytes, increases the risk of lysing the oocytes and the transfer of animal-derived pathogens. All this can be avoided by using a highly pure, non-toxic and effective recombinant human hyaluronidase, which requires less mechanical denudation, reduces oocyte damage, increases fertilization, embryo quality and pregnancy rates. During the ICSI procedure the sperm are subjectively selected. However, it is now possible to Backgroundly select motile sperm, via their hyaluron receptors, of a better morphology, higher chromatin stability and lower incidence of aneuploidy, which improves fertilization rates, embryo quality, blastulation and ongoing pregnancy rates -“Physiological ICSI”.

With the advent of human assisted reproduction in the year 1978 numerous techniques were developed to isolate spermatozoa capable to fertilize oocytes. While early methodologies only focused on the aim of isolating viable, motile spermatozoa, with further progress of assisted reproductive technology, particularly for ICSI, it rapidly became clear that these two parameters are insufficient for the identification of the most suitable and most functional spermatozoon for fertilization. Conventional sperm preparation techniques, namely swim-up, density gradient centrifugation or glass wool filtration are definitely not efficient enough to isolate sperm populations that minimize or even exclude the risk of the transfer of mutagenic or lethal DNA damages to the progeny. This is because these conventional sperm preparation techniques are physical rather than physiological and are not modeled on the sperm selection processes taking place in the female genital tract. Therefore, reproductive biology/medicine should learn from nature and try to mimic the extremely stringent selection process in the female genital tract, which only allows one male germ cell out of tens of millions to fuse with the oocyte.Sites of natural sperm selection in the female genital tract are the cervix with its mucus, uterus, utero-tubal junction, oviduct, cumulus oophorus and the zona pellucida. Newer and more sophisticated (advanced) strategies of sperm preparation intend to mimic the principles underlying physiologic sperm selection founded on (i) sophisticated morphological assessment by means of ‘motile sperm organelle morphological examination (MSOME), (ii) electrical charges and (iii) molecular binding characteristics of the sperm cell. Whereas separation methods based on electrical charge take advantage of the sperm cells’ zeta potential to either adhere to the test tube surface or movement by electrophoresis, molecular binding techniques use annexin V or hyaluronan as substrate for sperm binding. Techniques to be mentioned in this category are magnetic-activated cell sorting technique (MACS), annexin V-activated glass wool filtration and flow cytometry as well as hyaluronic acid (HA)-bound spermatozoa that are removed by gently rinsing the HA droplet so that the bound spermatozoon can be removed or picked (P) with an ICSI pipette (PICSI) from the dish. Future developments may include Raman microspectrometry, confocal light absorption and scattering spectroscopic (CLASS) microscopy and the use of the birefringence of the sperm head.