Assisted Reproductive Technology: Advances in Microfluidics‐Based Assisted Reproductive Technology: From Sperm Sorter to Reproductive System‐on‐a‐Chip (Adv. Biosys. 3/2018)

Abstract

Keywords: Continuous-flow/droplet based/paper-based microfluidics, Sperm/oocyte selection, Microfluidic embryo culture, Oviduct-on-a-chip, Womb-on-a-chip Abstract: Assisted reproductive technology (ART) and in vitro fertilization (IVF) are among the greatest achievements of medicine and life science. The field has been progressed rapidly; yet, physical environment and manipulation techniques need further improvement. Over the past two decades, the application of microfluidics has been attracting increasing attention in the field of ART. Microfluidic platforms can incorporate various ART procedures such as embryo/gamete (sperm/oocyte) analysis, sorting, manipulation, culture, and monitoring. However, most of the reported works have only focused on continuous-flow (single phase) microfluidics and have been the subject of recent review articles. In line with advances in ART, microfluidics has also evolved in the last few years. The introduction of paper-based and droplet-based microfluidics further improved the commercialization potential of this technology. The rapid progress in three-dimensional (3D) printing technology allows for the integration of microfluidics with tissue engineering that may revolutionize current practices in biology and medicine. This review paper categorizes microfluidic methods in ART according to continuous-flow microfluidics, paper-based microfluidics, droplet-based microfluidics and organ-on-a-chip. We summarize the advances and identify potential opportunities of each method in different areas of ART including infertility diagnosis, sperm 2 selection, sperm guidance, oocyte selection, insemination, embryo culture, embryo monitoring and cryopreservation. While some advances of continuous-flow microfluidics in ART has already been reviewed, other microfluidic techniques are still in their early stages. We envision that advances in droplet-based microfluidics, especially digital microfluidics with liquid marble and electrowetting-on-dielectric, will allow further progress in human IVF, particularly single embryo transfer. Droplet-based microfluidics can also lead to fully integrated and high-throughput platforms for animal IVF. Recent advances in organ-on-a-chip including ovary/uterus/oviduct-on-chip platforms hold promise for the next step integration of whole human reproductive system-on-a-chip for clinical ART application. Yet, there are still many biological and technological challenges needed to be addressed before such devices can be translated to clinical IVF settings.