Nanotechnology-based approach for safer enrichment of semen with best spermatozoa

Background: Advances in nanotechnology have permitted molecular-based targeting of cells through safe and biocompatible magnetic nanoparticles(MNP). Their use to detect and remove damaged spermatozoa from semen doses could be of great interest. Here, MNP were synthesized and tested for their ability to target apoptotic(annexin V) and acrosome-reacted(lectin) boar spermatozoa, for high-throughout retrieval in a magnetic field(nanoselection). The potential impacts of nanoselection on sperm functions and performance of offspring sired by sperm subjected to nanoselection were determined. Fresh harvested and extended boar semen was mixed with various amounts(0, 87.5, and 175 μg) of MNP-conjugates(Annexin V-MNP or Lectin-MNP) and incubated(10 to15 min) for 37 °C in Exp. 1. In Exp. 2, extended semen was mixed with optimal concentrations of MNP-conjugates and incubated(0, 30, 90, or 120 min). In Exp. 3, the synergistic effects of both MNP-conjugates(87.5 μg– 30 min)on spermatozoa was evaluated, followed by sperm fertility assessments through pregnancy of inseminated gilts and performance of neonatal offspring. Sperm motion, viability, and morphology characteristics were evaluated in all experiments.Results: Transmission electron microscopy, atomic force microscopy, and hyperspectral imaging techniques were used to confirm attachment of MNP-conjugates to damaged spermatozoa. The motility of nanoselected spermatozoa was improved(P < 0.05). The viability of boar sperm, as assessed by the abundance of reactive oxygen species and the integrity of the acrosome, plasma membrane, and mitochondrial membrane was not different between nanoselected and control spermatozoa. The fertility of gilts inseminated with control or nanoselected spermatozoa, as well as growth and health of their offspring were not different between(P > 0.05).Conclusions: The findings revealed the benefit of magnetic nanoselection for high-throughput targeting of damaged sperm, for removal and rapid and effortless enrichment of semen doses with highly motile, viable,and fertile spermatozoa. Therefore, magnetic nanoselection for removal of abnormal spermatozoa from semen is a promising tool for improving fertility of males, particularly during periods, such as heat stress during the summer months.

Proteome changes of porcine follicular fluid during follicle development

Background:Ovarian follicular fluid influences follicle and oocyte growth,but the fluctuation of its protein content during folliculogenesis has not been comprehensively analyzed.Here we used a shotgun approach and bioinformatics analyses to investigate and compare the proteomes of porcine follicular fluid(pFF)obtained from small(<4 mm),medium(4–6 mm)and large(>6–12 mm)follicles.Results:Follicular fluid samples containing highest estrogen levels were selected as non-atretic from small(SNA:26.1±15 ng/mL),medium(MNA:162±54 ng/mL),and large(LNA:290±37 ng/mL)follicles for proteomic analyses.We detected 1627,1699,and 1756 proteins in SNA,MNA,and LNA samples,respectively.Nearly 60–63%of total proteins were specific to each sample,11–13%were shared in pairwise comparisons,and 247 proteins were shared among all samples.Functional categorization indicated comparable gene ontology(GO)terms distribution per cellular component,molecular function,and biological process categories across samples;however,the ranking of highly significantly enriched GO terms per category revealed differences between samples.The patterns of proteinto-protein interactions varied throughout follicle development,and proteins such as serine protease inhibitor,clade E(SERPINE);plasminogen activator,urokinase(PLAU);and plasminogen activator,urokinase receptor(PLAUR)appeared stage-specific to SNA,MNA,and LNA,respectively.The“complement and coagulation cascades”was the common major pathway.Besides,properdin and fibulin-1 were abundant proteins that appeared absent in LNA samples.Conclusion:This study provides extensive and functional analyses of the pFF proteome changes during folliculogenesis and offers the potential for novel biomarker discovery in pFF for oocyte quality assessment.