title: Screening of sperm velocity by fluid mechanical characteristics of a cyclo-olefin polymer microfluidic sperm-sorting device.
abstract: The microfluidic sperm-sorting (MFSS) device is a promising advancement for assisted reproductive technology. Previously, poly(dimethylsiloxiane) and quartz MFSS devices were developed and used for intracytoplasmic sperm injection. However, these disposable devices were not clinically suitable for assisted reproduction, so a cyclo-olefin polymer MFSS (COP-MFSS) device was developed. By micromachining, two microfluidic channels with different heights and widths (chip A: 0.3 × 0.5 mm; chip B: 0.1 × 0.6 mm) were prepared. Sorted sperm concentrations were similar in both microfluidic channels. Linear-velocity distribution using the microfluidic channel of chip B was higher than that of chip A. Using confocal fluorescence microscopy, it was found that the highest number of motile spermatozoa swam across the laminar flow at the bottom of the microfluidic channel. The time required to swim across the laminar flow was longer at the bottom and top of the microfluidic channels than in the middle because of the low fluid velocity. These results experimentally demonstrated that the width of microfluidic channels should be increased in the region of laminar flow from the semen inlet to the outlet for unsorted spermatozoa to selectively recover spermatozoa with high linear velocity.
authors: Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
authors: Koji
authors: K
authors: Matsuura
authors: Mami
authors: M
authors: Takenami
authors: Yuka
authors: Y
authors: Kuroda
authors: Toru
authors: T
authors: Hyakutake
authors: Shinichiro
authors: S
authors: Yanase
authors: Keiji
authors: K
authors: Naruse
mesh_terms: D000328:Adult; D000475:Alkenes / Q000737:chemistry*; D002469:Cell Separation / Q000379:methods; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D004867:Equipment Design; D006801:Humans; D008297:Male; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D018613:Microscopy, Confocal / Q000379:methods; D011108:Polymers / Q000737:chemistry*; D013081:Sperm Motility; D013094:Spermatozoa / Q000473:pathology*; D013997:Time Factors
chemical_list: D000475:Alkenes; D004129:Dimethylpolysiloxanes; D011108:Polymers; C013830:baysilon