A novel approach to sperm selection: Nanoparticle-based purification improves quality of Angora cryopreserved buck's semen

The aim of the study was to investigate the applicability of an up-to-date method, sperm selection with nanoparticles at different temperatures (37 degrees C, 21 degrees C, and 4 degrees C), on Angora buck semen. Semen samples were collected from 3 Angora bucks (2-4 years old) with 7 repetitions and each sample was diluted with TRIS+egg yolk (TEYG) and divided into 4 groups. Nanopurification procedure was applied by using nanoparticles in the form of a cocktail of iron oxide nanoparticles coated with silica magnetite, Annexin-V and Pisum sativum agglutin (PSA) with a dose of 10 mu g/ ml to the three groups at 37 degrees C, 21 degrees C, and 4 degrees C while in the control group samples were cryopreserved without nanopurificiation treatment. Post-thaw total motility (TM) and morphology parameters of the sperm samples were analyzed by using computer-aided sperm analysis (CASA) and fluorescein microscopy in which, Arachis hypogaea (peanut) lectin (FITC-PNA, 1 mg lyophilized powder, Sigma) and JC-1 (5 mg, Invitrogen, Thermo Fischer Scientific) Fischer Scientific) stains were used. After nanopurification at 37 degrees C total motility, linearity (LIN) (P<0.05), curvilinear velocity (VCL), straight-line velocity (VSL), and acrosome integrity parameters (P<0.001) were higher than the control group; while the semen samples nanopurified at 21 degrees C were superior to the control group in terms of LIN, straightness (STR) (P<0.05), VCL, VSL, average path velocity (VAP), wobble and plasma membrane-acrosome integrity (PMAI) (P<0.001). There was no significant difference between the control and the 4 degrees C group. Also,there were no differences between the groups in terms of mitochondrial activation rates (p=0.892) by fluorescent staining. In conclusion, nanopurification procedure on buck semen was useful in terms of parameters that affect fertility and the method can be performed at 21 degrees C, as well as 37 degrees C, to adapt the procedure to field conditions.