Search

The advent of nanotechnology since the 1950s, when the well‐known physicist Richard P. Feynman talked in his famous talk about "There's plenty of room at the bottom", has led to incredible contribution of nanotechnology in the fields of medical and veterinary therapeutics, diagnostics and other applications. Semen biology dealing with the study of spermatozoa and its related physiological and pathological aspects has not remained unscathed from the facets of nanotechnology. With each passing day investigators are revealing newer aspects of the nanoparticles, such as an antioxidants to relieve oxidative stress during semen cryopreservation, for the depletion of moribund spermatozoa from semen, gender selection of spermatozoa, bio‐imaging of gametes, sperm mediated gene transfer, as well as for male fertility evaluation. As, the uses of various magnetic nanoparticles in the industry have gained acceleration, the evaluation of their effects, either beneficial or otherwise on the mammalian spermatozoa becomes obligatory. Many toxicological studies have also been conducted in respect to the harmful effects of different metallic nanoparticles related to their applicability, and industry borne adverse effects on the male germ cells in human beings and the animals. This review has been designed to focus on the beneficial as well as toxicological effects of various metallic nanoparticles on the mammalian spermatozoa and the future prospects related to their applicability in the semen biology. [ABSTRACT FROM AUTHOR]

The synthesis of iron oxide nanoparticles (IONPs)–antiubiquitin antibodies (Abs) complex for depletion of dead/damaged spermatozoa from buffalo semen was done. The IONPs synthesized were round in shape with size of 12.09 ± 0.91 nm. At the end of the two‐step functionalization, that is, silanization and pegylation of bare IONPs and bioconjugation of functionalized IOPNs, particles with the sizes of 19.15 ± 1.46, 20.72 ± 0.95, and 73.01 ± 7.56 nm, respectively, were obtained. Twenty‐four semen samples from four bulls with mean individual progressive motility (%) and sperm concentration (million/mL) of 77.1 ± 0.9 and 1,321.2 ± 84.7, respectively, were divided into Group I (control), and treatment groups viz. Groups II, III, and IV; with each group containing 150 ± 25 million dead/damaged spermatozoa. The IONPs–Abs complex was added at the ratio of 1:1 (0.5 μg/mL), 1:2 (1.0 μg/mL), and 1:4 (2.0 μg/mL), respectively, in the Groups II, III, and IV. The mean efficiency (%) of nanopurification was estimated to be greater in nanopurified semen with the increasing doses of the IONPs–Abs complex. A reduction of 29.3 ± 6.4%, 48.4 ± 5.3%, and 55.4 ± 4.4% in dead/damaged spermatozoa following nanopurification in Groups II, III, and IV, respectively, was observed. The study shows that in‐house synthesized IONPs–Abs complex can be successfully used to deplete dead/damaged spermatozoa from buffalo semen with improvement in quality. [ABSTRACT FROM AUTHOR]

Since ensuring stability of the nanoparticles in aqueous-phase is essential for biomedical applications, this study evaluated the effect of ultra-sonication followed by peptization on iron-oxide nanoparticles (IONPs) aqueous-phase stability. The IONPs synthesized via two different chemical co-precipitation methods were ultra-sonicated for −5, −10 and 20-min and evaluated using Dynamic light scattering at Day-1, -2, -7 and -15 of the synthesis. The Experiment II-IONPs had lesser hydrodynamic size with better aqueous-phase stability over the time. The decrease in the average size and increase in homogeneity of solution was better following ultra-sonication for 20-min. These IONPs were peptized with perchloric acid to evaluate the effect on stability and longevity. The results showed large proportion of IONPs less than 100 nm even on day-15 post-peptization. Moreover, transmission electron microscopy revealed average size of 11.23 nm with round shape. The study showed positive influence of peptization on the aqueous-phase stability of the IONPs. [ABSTRACT FROM AUTHOR]

The study consisted of application of anti‐ubiquitin antibodies (Abs)‐coated iron oxide‐nanoparticles (IONPs) for minimisation of oxidative stress to contemporary live spermatozoa from the raw semen. Round‐shaped IONPs (12.09 ± 0.91 nm) after two‐stage functionalisation (silanisation and pegylation) were conjugated with Abs. Four aliquots from each of the 24 ejaculates (4 buffalo bulls) formed Control (Group I) and treatment (II, III and IV) groups; each containing 150 ± 25 million dead/damaged spermatozoa. IONPs‐Abs complex were added at ratio of 1:1 (0.5 µg/ml), 1:2 (1.0 µg/ml) and 1:4 (2.0 µg/ml), respectively, in Groups II, III and IV. The semen quality parameters showed improvement at lag‐stage (post‐nano‐purification before processing for cryopreservation). The mean post‐thaw motility (%) in Group IV was found to be greater (p <.05) than Group I. Moreover, the overall DNA integrity (%) at post‐thaw stage was improved in the nano‐purified semen samples. The value of malondialdehyde was greater (p <.001) in Group I than Groups II, III and IV. The mean total antioxidant capacity and superoxide dismutase (U/mg protein) activity values in Group IV was greater (p <.05) than Group I. The study results show that IONPs conjugated with anti‐ubiquitin Abs at 2.0 µg/ml can be an effective dose for depletion of dead/damaged spermatozoa from buffalo ejaculates to minimise oxidative stress. [ABSTRACT FROM AUTHOR]

Despite recent advances in technique of spermatozoa cryopreservation, there are still ejaculates present that fail to meet strict quality standard; mainly due to detrimental effect of imbalance of free radicals. The omnipresence of dead/defective spermatozoa in ejaculates of eutherian species is a major source of excessive free radicals. Though sperm-selection techniques, as well as addition of antioxidants addressed the problem to a certain extent, the major source of free radicals in the semen remained, causing much damage. This study attempts to remove dead/damaged spermatozoa using negative fertility-marker. The effect is unraveled by Hypo-osmotic (HOS), and fluorescein-conjugated Pisum sativum agglutinin (FITC-PSA) assay, further confirmed by Ca2+-regulating mechanisms and depolarization of sperm membrane potential, reduction in concentration of free radicals and finally by in vitro fertility assay. The study involved functionalization of iron oxide nanoparticles (IONPs) with silane followed by bio-conjugation with anti -ubiquitin antibodies. The nano-purification of semen using anti -ubiquitin conjugated iron oxide nanoparticles (IONPs) (antibody concentrations 0.5, 1.0 and 2.0 μg/ml) was attempted. The efficiency of nano-purification was 18.1%–43.8% in the study. The results revealed greater (P ≤ 0.05) spermatozoa population with intact plasma membrane, acrosome integrity, high mitochondrial membrane potential and pattern-F (least intracellular Ca2+), evidence of low lipid peroxidation and higher total antioxidant capacity in nano-purified groups. More number of spermatozoa were bound to zona pellucida of matured oocytes from nano-depleted than non-depleted group. The findings demonstrate antibody concentration of 1.0 μg/ml bio-conjugated with IONPs as most efficient in enriching the ejaculate with functional spermatozoa with the highest percentage of zona binding. • Nano-purification improves semen quality in buffalo. • Removal of dead and damaged spermatozoa reduces the oxidative stress level in semen. • Nano-purification improves the fertility of semen. [ABSTRACT FROM AUTHOR]

Background: Oxidative stress is one of the leading factors responsible for poor post‐thaw semen quality because of overproduction of reactive oxygen species (ROS) over neutralizing antioxidants present in semen. Mainly two ROS generation sites are present in spermatozoa, that is, mitochondria and plasma membrane. Therefore, the idea of targeting these specific sites for minimization of ROS production with the compounds having known mechanism of actions was built up as a core for this research. Objective: Present study was done to investigate the effects of Mito TEMPO and acetovanillone individually and in combination on freezability of buffalo spermatozoa. Materials and Methods: For the experiment, semen extender was supplemented with Mito TEMPO (50 μM), acetovanillone (50 μM), and a combination of Mito TEMPO + acetovanillone (50 μM+ 50 μM), designated as Group II, Group III, and Group IV, respectively. Control group without any supplementation was designated as Group I. A total of 24 ejaculates with individual progressive motility (IPM) of ≥70% were selected for the study. After final dilution, filling‐sealing of straws, equilibration, and freezing were done as per the standard procedure. Semen samples were evaluated for IPM, plasma membrane integrity, lipid peroxidation, total antioxidant capacity (TAC), and cholesterol to phospholipids (C/P) ratio at both fresh and post‐thaw stages. Evaluation of ROS, mitochondrial membrane potential (MMP), capacitation status (CTC assay), and in vitro fertility potential were conducted only on frozen‐thawed samples. Results: The addition of Mito TEMPO (50 μM) and acetovanillone (50 μM) individually and in combination significantly (p < 0.05) improved post‐thaw semen quality in terms of IPM, plasma membrane integrity, TAC, cholesterol content, C/P ratio, MMP, Chlortetracycline (CTC)‐Full (F) pattern, and zona binding ability of buffalo spermatozoa, while significantly (p < 0.05) reduced ROS production, lipid peroxidation, and capacitation like changes as compared to the control group. Discussion: As Mito TEMPO acts as an SOD mimetic and also detoxifies ferrous iron at the mitochondria level, it aids in neutralization of excessive ROS production and minimizes oxidative stress‐related damages that enhances the antioxidant potential of sperm mitochondria. Earlier studies also indicated improved post‐thaw semen quality in 50 μM supplemented group. The improvement observed in acetovanillone (50 μM) group might be because of inhibition of Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase as this enzyme activation by various physical/chemical inducers during cryopreservation process leads to activation of CatSper channel resulting in calcium influx, premature capacitation, and acrosomal reaction like changes through activation of adenylate cyclase and cAMP/PKA‐mediated tyrosine phosphorylation of sperm proteins. Acetovanillone also prevents NADPH oxidase–mediated inhibition of glutathione reductase activity, which has a vital role in protecting the structural and functional integrity of sperm plasma membrane. Conclusion: Results indicated beneficial effects of supplementation of Mito TEMPO and acetovanillone on sperm freezability and individual supplementation was as efficient as the combination group for sustaining post‐thaw semen quality. [ABSTRACT FROM AUTHOR]

The current study intended to optimize the concentration of Oxyrase in the semen dilutor and to evaluate its effect on freezability of spermatozoa of Sahiwal bulls. Supplementation of Oxyrase at 0.125 IU/mL concentration significantly reduced dissolved oxygen (DO) in the dilutor to 4 ppm in 16–18 min at 35 °C. For supplementation studies, a total of 24 ejaculates were categorized into poor and good ejaculates categories (n = 12 each) based on their initial progressive motility. Each ejaculate was further divided into two aliquotes. The first aliquote was diluted with tris-egg yolk extender without Oxyrase (control group) whereas, in the treatment group, Oxyrase was supplemented at the concentration of 0.125 IU/mL of extender. The parameters evaluated include cholesterol and plasma membrane phospholipids (PMP) at fresh, while IPM, acrosomal and plasma membrane integrity, cholesterol, PMP and oxidative stress parameters like lipid peroxidation (LPO), total antioxidant capacity (TAC) and reactive oxygen species (ROS) were evaluated at pre-freeze and post-thaw stages. The IPM and acrosomal intactness were higher (p < 0.05) in treatment group at post-thaw stage in good ejaculates. Oxyrase supplementation resulted in lower (p < 0.05) cholesterol leakage in both categories and lower (p < 0.05) LPO in good ejaculates at post-thaw stage. No statistical difference in ROS was observed between control and treatment groups at all stages whereas, level of TAC was higher (p < 0.05) in the treatment group compared to control group at post-thaw stage of both categories. Therefore, Oxyrase as an oxygen scavenging agent could preserve the post-thaw quality of Sahiwal bull spermatozoa. [ABSTRACT FROM AUTHOR]