Separation of progressive motile sperm from mouse semen using on-chip chemotaxis.
10 Jan 2012-Analytical Sciences (The Japan Society for Analytical Chemistry)-Vol. 28, Iss: 1, pp 27-27
TL;DR: This device provides a convenient, disposable, and high-throughput platform that could function as a progressive motile sperm sorter for potential use in intracytoplasmic sperm injection.
Abstract: We present a novel method for the separation of progressive motile sperm from non-progressive motile and immotile sperm. This separation was accomplished by inducing chemotaxis along a longitudinal chemical gradient in a microchip composed of a biocompatible polydimethysiloxane layer and a glass substrate. In a preliminary experiment using fluorescent rhodamine B as a marker, we verified that a chemical gradient was generated by diffusion within the microchannel. We used acetylcholine as a chemoattractant to evaluate the chemotactic response of sperm. We tested the response to a 1/2 to 1/64 dilution series of acetylcholine. The results of a mouse sperm chemotaxis assay showed that progressive motile sperm swam predominantly toward the outlet at an optimal chemical gradient of 0.625 (mg/ml)/mm of acetylcholine. This device provides a convenient, disposable, and high-throughput platform that could function as a progressive motile sperm sorter for potential use in intracytoplasmic sperm injection.
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27 Jun 2018
TL;DR: Experimental results show that motile mouse sperm are attracted more sensitively under integrated conditions of chemotaxis and thermotaxis rather than individual conditions ofChemoattractant and thermOTaxis.
Abstract: Infertile couples needing assisted reproduction are increasing, so a fundamental understanding of motile sperm migration is required. This paper presents an advanced microfluidic device for sperm motion analysis utilizing chemotaxis and thermotaxis simultaneously for the first time. The proposed device is a transparent polydimethylsiloxane- and glass-based microfluidic chip system providing a low-cost, useful, and disposable platform for sperm analysis. The concentration gradient of the chemoattractant (acetylcholine) and the temperature difference are formed along the microchannel. The temperature gradient is generated and controlled by a microheater and microsensor. Thermotactic and chemotactic responses of mouse sperm were examined using the proposed device. Experimental results show that motile mouse sperm are attracted more sensitively under integrated conditions of chemotaxis and thermotaxis rather than individual conditions of chemotaxis and thermotaxis. This sperm analysis device is expected to be a useful tool for the study of mammalian sperm migration and the improvement of artificial insemination techniques.
29 citations
TL;DR: Clinical protocols associated with the processing of a microTESE sample are inefficient and significantly reduce the success of obtaining a viable sperm population, and how these sources can possibly be removed by microfluidic technology and single-cell Raman spectroscopy is highlighted.
Abstract: Non-obstructive azoospermia (NOA) is a severe form of infertility accounting for 10% of infertile men. Microdissection testicular sperm extraction (microTESE) includes a set of clinical protocols from which viable sperm are collected from patients (suffering from NOA), for intracytoplasmic sperm injection (ICSI). Clinical protocols associated with the processing of a microTESE sample are inefficient and significantly reduce the success of obtaining a viable sperm population. In this review we highlight the sources of these inefficiencies and how these sources can possibly be removed by microfluidic technology and single-cell Raman spectroscopy.
27 citations
TL;DR: A simple, easy to fabricate and handle, flow-free microfluidic chip is described to test the chemotactic response of spermatozoa made out of a hybrid hydrogel (8% gelatin/1% agarose).
Abstract: Current male fertility diagnosis tests focus on assessing the quality of semen samples by studying the concentration, total volume, and motility of spermatozoa. However, other characteristics such as the chemotactic ability of a spermatozoon might influence the chance of fertilization. Here we describe a simple, easy to fabricate and handle, flow-free microfluidic chip to test the chemotactic response of spermatozoa made out of a hybrid hydrogel (8% gelatin/1% agarose). A chemotaxis experiment with 1 μM progesterone was performed that significantly demonstrated that boar spermatozoa are attracted by a progesterone gradient.
26 citations
TL;DR: In this article, a planar stack with flow-over electrodes of platinum is proposed to increase the total power of a microfluidic fuel cell, where electrical connections in serial or parallel are made within one channel by using multiple laminar flow.
26 citations
TL;DR: An on-chip system that mimics tubular microenvironments of diameters 20-45 μm facilitate sperm migration through channels and the influence of tube diameter on the velocity, directionality, and linearity of spermatozoa is investigated.
Abstract: An on-chip system that mimics tubular microenvironments is presented for the study of spermatozoa motion in confinement. Using rolled up transparent silicon oxide/dioxide microtubes, the influence of tube diameter on the velocity, directionality, and linearity of spermatozoa is investigated. Tubular microenvironments of diameters 20-45 μm facilitate sperm migration through channels.
24 citations
References
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TL;DR: Highly integrated microdevices show great promise for basic biomedical and pharmaceutical research, and robust and portable point-of-care devices could be used in clinical settings, in both the developed and the developing world.
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TL;DR: The mechanisms by which mammalian sperm cells are guided to the egg are reviewed.
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462 citations
TL;DR: A transparent 3D microfluidic channel-based cell culture system that allows cells to be perfusion-cultured in 3D by supporting them with adequate 3D cell-cell and cell-matrix interactions and allows direct optical monitoring of cellular events for a wide range of applications.
Abstract: Mammalian cells cultured on 2D surfaces in microfluidic channels are increasingly used in drug development and biological research applications. These systems would have more biological or clinical relevance if the cells exhibit 3D phenotypes similar to the cells in vivo. We have developed a microfluidic channel based system that allows cells to be perfusion-cultured in 3D by supporting them with adequate 3D cell–cell and cell–matrix interactions. The maximal cell–cell interaction was achieved by perfusion-seeding cells through an array of micropillars; and 3D cell–matrix interactions were achieved by a polyelectrolyte complex coacervation process to form a thin layer of matrix conforming to the 3D cell shapes. Carcinoma cell lines (HepG2, MCF7), primary differentiated (hepatocytes) and primary progenitor cells (bone marrow mesenchymal stem cells) were perfusion-cultured for 72 hours to 1 week in the microfluidic channel, which preserved their 3D cyto-architecture and cell-specific functions or differentiation competence. This transparent 3D microfluidic channel-based cell culture system also allows direct optical monitoring of cellular events for a wide range of applications.
422 citations