Review
Microfluidics for sperm research

https://doi.org/10.1016/j.tibtech.2015.01.005Get rights and content

Highlights

  • Microfluidics techniques have been developed to sort sperm for in vitro fertilization.

  • There are emerging applications in single-sperm genomics and in-home fertility testing.

  • Sperm sorting has been also applied to wildlife conservation efforts.

  • Microfluidics can also serve as a platform for bio-games utilizing sperm-robots.

  • We review a broad range of studies applying microfluidics to sperm research.

One in six couples of reproductive age worldwide are affected at least once by some form of infertility. In vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) are widely-available assisted reproductive technologies (ART). The identification and isolation of the most-motile sperm with DNA integrity are essential to IVF and ICSI, ultimately affecting treatment consequences and the health of offspring. Recently, microfluidic technologies been developed to sort sperm according to sperm morphology, motility, DNA integrity, and functionality for IVF techniques. There have also been emerging applications in wildlife conservation, high-throughput single-sperm genomics, sperm-driven robotics, and in-home fertility testing. We review a broad range of studies applying the principles of microfluidics to sperm research.

Section snippets

Current need for sperm-sorting technologies

Infertility affects about 50–80 million couples worldwide, accounting for 8–12% of couples with women of reproductive age [1]. Male infertility contributes to about one half of infertility cases [2]. Most cases are due to low sperm count, which is commonly caused by primary testicular failure. Nutritional deficiencies, stress, chronic inflammation, and environmental exposure to particular toxins can also decrease sperm quantity and quality. Low sperm count, low sperm motility, and sperm

Conventional technologies

Selection of sperm for IVF and ICSI is generally based on sperm motility because highly motile sperm are more capable of fertilizing an oocyte. Traditional sperm-selection techniques include the swim-up and density gradient-based centrifugation methods 15, 16. The swim-up method enables motile sperm to move away from its cohort of sedimented sperm into freshly layered media; however, the technique produces a low yield of motile sperm. Density gradient-based centrifugation can select sperm cells

What does the field of microfluidics hold for in vitro sperm research?

PMMA/PDMS-based microfluidic chips with a glass substrate enable direct microscopic imaging of the sample. Although these chips are convenient for sperm research, there remain some shortcomings, such as the thickness of these chips and the need for specialized instruments for chip fabrication. Hence, paper-based microfluidic chips are being investigated as a cheaper alternative. Earlier versions of paper microfluidic chips were opaque cellulose-based chips. However, these devices fall short

Concluding remarks and future perspectives

Microfluidic lab-on-a-chip devices have been proven to be effective in both (i) analyzing a wide range of sperm functions and (ii) selecting progressive motile sperm from a mixture of seminal plasma, non-reproductive cells, mature and immature spermatozoa, non-specific debris, and various microorganisms to improve IVF outcome. Conventional methods for sperm sorting can induce DNA damage, require labor-intensive procedures, and often yield low purity. There has been an increasing effort to

References (68)

  • D. Lange

    A microfluidic shadow imaging system for the study of the nematode Caenorhabditis elegans in space

    Sens. Actuators B

    (2005)
  • S. Moon

    Integrating microfluidics and lensless imaging for point-of-care testing

    Biosens. Bioelectron.

    (2009)
  • Infertility: A Tabulation of Available Data on Prevalence of Primary and Secondary Infertility

    (1991)
  • J.G. Raymond

    Women as Wombs: Reproductive Technologies and the Battle over Women's Freedom

    (1993)
  • J. Rajfer

    Freeze that sperm

    Rev Urol

    (2006)
  • J. Rajfer

    Sperm health in the aging male

    Rev Urol

    (2006)
  • J. Rajfer

    Fertility

    Rev Urol

    (2006)
  • P. Hansen

    Current and future assisted reproductive technologies for mammalian farm animals

  • A. Lemma

    Effect of cryopreservation on sperm quality and fertility

  • G.M. Whitesides

    The origins and the future of microfluidics

    Nature

    (2006)
  • E.K. Sackmann

    The present and future role of microfluidics in biomedical research

    Nature

    (2014)
  • D. Psaltis

    Developing optofluidic technology through the fusion of microfluidics and optics

    Nature

    (2006)
  • C.M. Boomsma

    Semen preparation techniques for intrauterine insemination

    Cochrane Database Syst. Rev.

    (2007)
  • R.R. Henkel et al.

    Sperm preparation for ART

    Reprod. Biol. Endocrinol.

    (2003)
  • T.G. Cooper

    World Health Organization reference values for human semen characteristics

    Hum. Reprod. Update

    (2010)
  • M. O’Connell

    The effects of cryopreservation on sperm morphology, motility and mitochondrial function

    Hum. Reprod.

    (2002)
  • M.D. Lopez-Garcia

    Sperm motion in a microfluidic fertilization device

    Biomed. Microdevices

    (2008)
  • U.A. Gurkan

    Smart interface materials integrated with microfluidics for on-demand local capture and release of cells

    Adv. Healthc. Mater.

    (2012)
  • U.A. Gurkan

    Emerging technologies for assembly of microscale hydrogels

    Adv. Healthc. Mater.

    (2012)
  • L. Gervais

    Microfluidic chips for point-of-care immunodiagnostics

    Advanced Materials

    (2011)
  • P. Yager

    Point-of-care diagnostics for global health

    Annu. Rev. Biomed. Eng.

    (2008)
  • S. Tasoglu

    The effects of inhomogeneous boundary dilution on the coating flow of an anti-HIV microbicide vehicle

    Phys. Fluids

    (1994)
  • S. Tasoglu

    Transient swelling, spreading, and drug delivery by a dissolved anti-HIV microbicide-bearing film

    Phys. Fluids

    (1994)
  • E. Verpoorte

    Microfluidic chips for clinical and forensic analysis

    Electrophoresis

    (2002)
  • Cited by (109)

    • Effects of photobiomodulation therapy on human sperm function

      2023, Revista Internacional de Andrologia
    • Development of a microfluidic system structured on a modified polydimethylsiloxane device for the selection of bovine epididymal spermatozoa

      2022, Reproductive Toxicology
      Citation Excerpt :

      The results presented in this study demonstrate the viability of bovine sperm after exposure to a microfluidic device manufactured with Silpuran® and provide perspectives for its application compared to other conventional in vitro reproduction techniques. For IVF purposes, the choice of technique for sperm selection is based mainly on motility since sperm with better motility have a greater capacity to fertilize the oocyte [35]. The present data confirm that the application of Silpuran® silicone was non-toxic to bovine spermatozoa and provided a more significant gain in parameters such as TM, PM, VCL, VSL and VAP.

    View all citing articles on Scopus
    View full text