Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Center for Bioengineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
Lab Chip. 2011 Aug 7;11(15):2535-40. doi: 10.1039/c1lc20236g. Epub 2011 Jun 16.
5.3 million American couples of reproductive age (9%) are affected by infertility, among which male factors account for up to 50% of cases, which necessitates the identification of parameters defining sperm quality, including sperm count and motility. In vitro fertilization (IVF) with or without intra cytoplasmic sperm injection (ICSI) has become the most widely used assisted reproductive technology (ART) in modern clinical practice to overcome male infertility challenges. One of the obstacles of IVF and ICSI lies in identifying and isolating the most motile and presumably healthiest sperm from semen samples that have low sperm counts (oligozoospermia) and/or low sperm motility (oligospermaesthenia). Microfluidic systems have shown potential to sort sperm with flow systems. However, the small field of view (FOV) of conventional microscopes commonly used to image sperm motion presents challenges in tracking a large number of sperm cells simultaneously. To address this challenge, we have integrated a lensless charge-coupled device (CCD) with a microfluidic chip to enable wide FOV and automatic recording as the sperm move inside a microfluidic channel. The integrated system enables the sorting and tracking of a population of sperm that have been placed in a microfluidic channel. This channel can be monitored in both horizontal and vertical configuration similar to a swim-up column method used clinically. Sperm motilities can be quantified by tracing the shadow paths for individual sperm. Moreover, as the sperm are sorted by swimming from the inlet towards the outlet of a microfluidic channel, motile sperm that reach the outlet can be extracted from the channel at the end of the process. This technology can lead to methods to evaluate each sperm individually in terms of motility response in a wide field of view, which could prove especially useful, when working with oligozoospermic or oligospermaesthenic samples, in which the most motile sperm need to be isolated from a pool of small number of sperm.
530 万美国育龄夫妇（9%）受到不孕不育的影响，其中男性因素占病例的 50%，这就需要确定定义精子质量的参数，包括精子计数和活力。体外受精（IVF）或卵胞浆内单精子注射（ICSI）已成为现代临床实践中最广泛使用的辅助生殖技术（ART），以克服男性不育的挑战。IVF 和 ICSI 的一个障碍在于从精子计数低（少精症）和/或精子活力低（弱精症）的精液样本中识别和分离最有活力和健康的精子。微流控系统已显示出通过流系统分选精子的潜力。然而，传统显微镜通常用于成像精子运动的小视野（FOV）在同时跟踪大量精子细胞方面存在挑战。为了解决这个挑战，我们将无透镜电荷耦合器件（CCD）与微流控芯片集成在一起，使精子在微流控通道内移动时能够实现宽 FOV 和自动记录。该集成系统能够对已放置在微流控通道中的精子群体进行分选和跟踪。该通道可以在水平和垂直配置中进行监测，类似于临床上使用的泳动法。通过跟踪单个精子的阴影路径，可以定量测量精子的运动能力。此外，由于精子通过从入口向微流控通道的出口游动而被分选，因此在运动到达出口的有活力的精子可以在过程结束时从通道中提取出来。这项技术可以导致在宽视场中评估每个精子的运动反应的方法，这在处理少精症或弱精症样本时尤其有用，因为需要从少数精子中分离出最有活力的精子。
