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When ejaculated sperm travels through the vagina to the uterus, mucus secreted by the cervical canal generally filters out sperm having low motility and poor morphology. To investigate this selection principle in vivo, we developed a microfluidic sperm-sorting chip with a viscous medium (polyvinylpyrrolidone: PVP) to imitate the biophysical environment mimic system of the human cervical canal. The material property of the PVP solution was tuned to the range of viscosities of cervical mucus using micro-viscometry. The selection of high-quality human sperm was experimentally evaluated in vitro and theoretically analyzed by the convection-diffusion mechanism. The convection flow is shown to be dominant at low viscosity of the medium used in the sperm-sorting chip when seeded with raw semen, hence, the raw semen containing sperm and debris convectively flow together with suppressed relative dispersions. Also, it was observed that the sperm selected via the chip not only had high motilities but also normal morphologies and high DNA integrity. Therefore, the biomimetic sperm-sorting chip with PVP medium is expected to improve male fertility by enabling the selection of high-quality sperm as well as uncovering pathways and regulatory mechanisms involved in sperm transport through the female reproductive tract for egg fertilization.

Sperm motility is a crucial factor for normal fertilisation that is partly supported by mitochondrial activity. Enzymatic biofuel cells (EBFCs) generate electric currents by an electron grade from anodic to cathodic electrodes in a culture media. We demonstrate that electrical stimulation by EBFC at the nano-Ampere range enhances sperm motility that can potentially allow the development of a new therapeutic tool for male infertility, including poor motility. EBFC was set up with three different electrical currents (112 nA/cm2 and 250 nA/cm2) at two different times (1 h, 2 h). Each sample was evaluated for its motility by computer-assisted sperm analyses and sperm viability testing. In the expanded study, we used the optimal electrical current of the EBFC system to treat asthenozoospermia and sperm with 0% motility. Results showed that optimal electrical stimulation schemes with EBFCs enhanced sperm motility by 30-40% compared with controls. Activated spermatozoa led to tyrosine phosphorylation in the tail area of the sperm following the electrical stimulation in the nano-Ampere range. However, the electrically stimulated group did not exhibit increased acrosomal reaction rates compared with the control group. In cases related to asthenozoospermia, 40% of motility was recovered following the electrical stimulation at the nano-Ampere range. However, motility is not recovered in sperm with 0% motility. In conclusion, we found that sperm motility was enhanced by exposure to electrical currents in the nano-Ampere range induced by optimal EBFCs. Electrical stimulation enhanced the motility of the sperm though tyrosine phosphorylation in spermatozoa. Therefore, our results show that electrical currents in the nano-Ampere range can be potentially applied to male infertility therapy as enhancers of sperm motility in assisted reproductive technology.

Objectives: To investigate the natural courses of mild, moderate and severe idiopathic oligozoospermia, and which factors or semen variables were of utmost importance in predicting the courses. Methods: A total of 208 men (age 29–47 years) who were diagnosed with mild, moderate and severe idiopathic oligozoospermia in a 9-year-period between January 2000 and December 2008 were followed up for more than 6 months. Results: Overall, 16 (24.6%) of 65 patients with severe oligozoospermia developed azoospermia, whereas two (3.1%) patients with moderate oligozoospermia developed azoospermia and none of the patients with mild oligozoospermia developed azoospermia. Initial follicle stimulating hormone level and testicular volume between the subgroups were significantly different (P = 0.0071 and 0.0039, respectively). The subgroup of patients who became azoospermic (n = 18) showed statistically significant differences in terms of body mass index and the level of prolactin (PRL) from the subgroup that maintained the initial lingering sperm count (n = 190; P = 0.0086 and 0.0154, respectively). As the vitality of semen variables increased 1%, the risk of progression to azoospermia diminished by 0.892-fold, according to Cox's proportional hazards model analysis. A receiver operating characteristic curve analysis showed that the area under the curve was 0.755 and the sperm concentration value with the highest sensitivity and specificity was the reference value of 3–5 million/mL, with a sensitivity of 0.746 and specificity of 0.711 (P = 0.01). Conclusions: Patients with severe oligozoospermia should be warned of the possibility of becoming azoospermic and hence sperm freezing should be encouraged as early as possible.

To investigate the natural courses of mild, moderate and severe idiopathic oligozoospermia, and which factors or semen variables were of utmost importance in predicting the courses.A total of 208 men (age 29-47years) who were diagnosed with mild, moderate and severe idiopathic oligozoospermia in a 9-year-period between January 2000 and December 2008 were followed up for more than 6months.Overall, 16 (24.6%) of 65 patients with severe oligozoospermia developed azoospermia, whereas two (3.1%) patients with moderate oligozoospermia developed azoospermia and none of the patients with mild oligozoospermia developed azoospermia. Initial follicle stimulating hormone level and testicular volume between the subgroups were significantly different (P=0.0071 and 0.0039, respectively). The subgroup of patients who became azoospermic (n=18) showed statistically significant differences in terms of body mass index and the level of prolactin (PRL) from the subgroup that maintained the initial lingering sperm count (n=190; P=0.0086 and 0.0154, respectively). As the vitality of semen variables increased 1%, the risk of progression to azoospermia diminished by 0.892-fold, according to Cox's proportional hazards model analysis. A receiver operating characteristic curve analysis showed that the area under the curve was 0.755 and the sperm concentration value with the highest sensitivity and specificity was the reference value of 3-5 million/mL, with a sensitivity of 0.746 and specificity of 0.711 (P=0.01).Patients with severe oligozoospermia should be warned of the possibility of becoming azoospermic and hence sperm freezing should be encouraged as early as possible.

Objective To evaluate the effectiveness of liquid nitrogen (LN 2 ) vapor (indirect contact method) for the storage of human semen. Design Experimental study. Setting University hospital-based fertility center. Patient(s) We evaluated 150 patients with normal sperm parameters. Intervention(s) Human semen (N = 120) was mixed with Semen Freezing Medium, divided into two groups, frozen, and stored in LN 2 or LN 2 vapor. Frozen semen from each group (n = 40) was thawed after storage for 1 week, 1 month, or 3 months and then analyzed. In the second experiment, semen (n = 30) was divided into four groups, frozen, and stored in LN 2 or stored 7 cm, 12 cm, or 17 cm above the surface of LN 2 for 1 week. Main Outcome Measure(s) The motility and viability of sperm were evaluated by basic analysis, the morphology was analyzed with use of staining, the DNA integrity was assessed with use of terminal deoxyuridine triphosphate nick end-labeling assays, and active mitochondria were detected with use of rhodamine 123 staining. Result(s) The LN 2 and LN 2 vapor groups did not differ with regard to sperm motility, viability, morphology, DNA integrity, or active mitochondria when the cryostorage periods were compared. Furthermore, the quality of sperm stored within 17 cm of the surface of LN 2 for 1 week did not change. Conclusion(s) The storage of human semen in LN 2 vapor, without direct contact with LN 2 , may represent a useful alternative for the effective storage of human semen.