Hyler Alexandra R, Thomas Dean E, Kinskie Kyle S, Brown Kyle M, Duncan Josie L, Cemazar Jaka, Schultz Jeff, Brown Simeon, Shiri Farhad, Soper Steven A, Swami Nathan S, Davalos Rafael V
CytoRecovery, Inc., Blacksburg, Virginia, USA.
Wallace H. Coulter Department of Biomedical Engineering, Georgia Tech-Emory University, Atlanta, Georgia, USA.
Electrophoresis. 2025 Feb 18. doi: 10.1002/elps.8113.
Understanding cells from complex biological samples is vital to understanding cellular biology and medical applications. One evolving tool for cell sorting is the use of microfluidic devices to achieve higher precision and remove the need for labeling cell subpopulations. However, few microfluidic devices have been translated commercially beyond academic research often due to challenges in larger scale fabrication. Here, we initially investigated a compelling label-free microfluidic device with complex geometries to perform contactless dielectrophoresis (cDEP) for applications in enriching cell subpopulations in oncology, neurology, stem cells, and sample preparation. We began scaling the manufacturing of cDEP devices using Dow Sylgard 184, more commonly referred to as PDMS (polydimethylsiloxane). However, we began observing a new, dynamic bubble formation phenomenon which had significant impacts on device performance. Within just 5 min of exposure at typical experimental values, cell death was nearly 100%. Variables related to manufacturing, environment, equipment, personnel, raw materials sourcing, lithography methods and experimental conditions/parameters were systematically evaluated to find the root cause of the exacerbated bubble formation observed. Further, alternate polymers were sourced for manufacturing and experimental performance comparisons. All variables investigated failed to solve the significant decline in device performance and increase in cell death. Upon completing chemical analysis in this work, we conclude that the decline in device performance was a direct result of changes to the expected PDMS properties and composition. Despite these challenges, our robust quality control combined with experimental protocols to remove bubbles from the cDEP devices achieved consistent experimental performance including 2-3 h run times and >90% cell viability after sorting. These new PDMS behaviors will need to continue to be monitored and controlled to ensure consistency in experimentation, application and commercialization feasibility for a wide variety of microfluidic device designs and applications.
了解复杂生物样本中的细胞对于理解细胞生物学和医学应用至关重要。一种不断发展的细胞分选工具是使用微流控设备，以实现更高的精度并消除对细胞亚群进行标记的需求。然而，由于大规模制造方面的挑战，除了学术研究之外，很少有微流控设备实现商业化。在这里，我们最初研究了一种具有复杂几何形状的引人注目的无标记微流控设备，用于进行非接触式介电电泳（cDEP），以应用于肿瘤学、神经学、干细胞和样本制备中的细胞亚群富集。我们开始使用陶氏Sylgard 184（更通常称为聚二甲基硅氧烷（PDMS））来扩大cDEP设备的制造规模。然而，我们开始观察到一种新的动态气泡形成现象，这对设备性能产生了重大影响。在典型实验值下暴露仅5分钟，细胞死亡率就接近100%。我们系统地评估了与制造、环境、设备、人员、原材料采购、光刻方法和实验条件/参数相关的变量，以找出观察到的气泡形成加剧的根本原因。此外，还采购了替代聚合物用于制造和实验性能比较。所有研究的变量都未能解决设备性能的显著下降和细胞死亡的增加问题。在完成这项工作中的化学分析后，我们得出结论，设备性能的下降是预期的PDMS特性和成分发生变化的直接结果。尽管存在这些挑战，但我们强大的质量控制与从cDEP设备中去除气泡的实验方案相结合，实现了一致的实验性能，包括2 - 3小时的运行时间和分选后>90%的细胞活力。这些新的PDMS行为将需要继续进行监测和控制，以确保在各种微流控设备设计和应用的实验、应用和商业化可行性方面的一致性。
