Sperm selection in assisted reproduction: A review of established methods and cutting-edge possibilities.

Male infertility often involves idiopathic or unknown causes, leading to an increasing demand for assisted reproduction technologies (ART). Conventional sperm sorting techniques rely on centrifugation steps that are known to cause oxidative stress and consequently damage cells.

Alternative novel techniques have been introduced but offer disadvantages that need to be overcome. These techniques are also employed to increase the number and the quality of subjects in the animal breeding industry, to obtain purebred subjects or to preserve endangered animal species. Microfluidics deals with the manipulation of small amounts of volume within a microdevice known as lab-on-a-chip (LOC), which offers rapid analyses, ease of use, small reagent sample volumes, high-throughput processing and wide reproducibility owing to automation and standardization. As the LOC allows gamete handling within a microenvironment that strictly mimics physiological in vivo conditions and avoids centrifugation steps and long processing time, the use of microfluidics for sperm sorting and selection have been proposed during the last 15 years and is currently under investigation. Moreover, LOC technologies to sort, identify and analyse other kinds of cells could be transferred to sperm selection and analysis, thus opening the way to a novel approach to the sperm cell selection and manipulation. This review describes the techniques routinely performed in human and animal clinical practice for sorting good-quality sperm for in vitro fertilization procedures, and focuses on the positive and negative aspects of each method. Emerging microfluidic devices, recently proposed for sperm selection, are also described and, when possible, compared with standard methods.

Biotechnology advances. 2019 Dec 10 [Epub ahead of print]

Giuseppina Marzano, Maria Serena Chiriacò, Elisabetta Primiceri, Maria Elena Dell'Aquila, João Ramalho-Santos, Vincenzo Zara, Alessandra Ferramosca, Giuseppe Maruccio

Department of Mathematics and Physics E. de Giorgi, University of Salento, Via per Arnesano, 73100 Lecce, Italy; Institute of Nanotechnology, CNR NANOTEC, Via per Monteroni, 73100 Lecce, Italy; Scuola Superiorie ISUFI (Istituto Superiore Universitario di Formazione Interdisciplinare), University of Salento, Via per Arnesano, 73100 Lecce, Italy., Institute of Nanotechnology, CNR NANOTEC, Via per Monteroni, 73100 Lecce, Italy. Electronic address: ., Institute of Nanotechnology, CNR NANOTEC, Via per Monteroni, 73100 Lecce, Italy., Department of Biosciences, Biotechnologies & Biopharmaceutics, University of Bari Aldo Moro, km3 strada per Casamassima, Valenzano, 70100 Bari, Italy., Biology of Reproduction and Stem Cell Group, CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Rua Larga, 3004-504 Coimbra, Portugal; Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal., Department of Biological and Environmental Sciences and Technologies, University of Salento, Via per Monteroni, 73100 Lecce, Italy., Department of Biological and Environmental Sciences and Technologies, University of Salento, Via per Monteroni, 73100 Lecce, Italy. Electronic address: ., Department of Mathematics and Physics E. de Giorgi, University of Salento, Via per Arnesano, 73100 Lecce, Italy; Institute of Nanotechnology, CNR NANOTEC, Via per Monteroni, 73100 Lecce, Italy.

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