Department of Materials Engineering, Indian Institute of Science, Bangalore 560012, India; Department of Medical Devices, National Institute of Pharmaceutical Education and Research, Ahmedabad, Gandhinagar, 382355, Gujarat, India.
Smart Materials and Surfaces Laboratory, Faculty of Engineering and Environment, Northumbria University, Newcastle upon Tyne, NE1 8ST, United Kingdom.
J Pharm Biomed Anal. 2019 Oct 25;175:112772. doi: 10.1016/j.jpba.2019.07.020. Epub 2019 Jul 21.
Blood microsampling is desired in clinical, pharmaceutical and biomedical fields to overcome the challenges of conventional whole blood sampling. One of the popular methods for blood microsampling is the dried blood spot (DBS) kit and the collected sample is subsequently used for bioanalysis. The current practice of DBS is simple to use, cheap and very well standardized from sample collection to analysis. However, DBS suffers from several well documented challenges related to blood spot formation such as varying hematocrit volume, thin layer chromatography effect and subsequent bio-analysis resulting in a variable and ocassionally high failure rate. A major source of these problems is our limited understanding of blood flow in porous media under different ambient and material conditions. Therefore, it is highly desirable to understand the parameters that affect blood flow in a porous medium to enable a more robust design of DBS and generally blood microsampling kits. In this review, we discuss some existing blood microsampling techniques while focusing on the challenges associated with blood flow dynamics. We also review existing studies on the potential factors that affect the permeation (imbibition or wicking) and spreading of blood in a thin, porous substrate as means to understand and overcome the challenges in designing new DBS kits and blood microsampling devices. Thereafter, we have discussed recent advances in the design of passive flow-based devices to overcome these challenges of current blood microsampling by DBS. Finally, we present a few applications of DBS in clinical and non-clinical studies. This review can benefit researchers working at the interface of complex fluid flow, surface chemistry, and material and device design for biomedical and biological applications.
临床、制药和生物医学领域都希望进行血液微采样，以克服传统全血采样的挑战。血液微采样的一种流行方法是干血斑（DBS）试剂盒，采集的样本随后用于生物分析。目前，DBS 的应用非常简单、廉价，从样本采集到分析都有很好的标准化。然而，DBS 存在一些众所周知的挑战，如血液斑形成时的红细胞压积体积变化、薄层层析效应以及随后的生物分析，导致结果的变异性和偶尔的高失败率。这些问题的一个主要来源是我们对不同环境和材料条件下多孔介质中血流的有限理解。因此，深入了解影响多孔介质中血流的参数对于更稳健的 DBS 设计以及一般的血液微采样试剂盒设计非常重要。在这篇综述中，我们讨论了一些现有的血液微采样技术，同时重点关注与血流动力学相关的挑战。我们还回顾了现有的研究，探讨了影响血液在薄的多孔基质中渗透（吸收或虹吸）和扩散的潜在因素，以了解和克服设计新的 DBS 试剂盒和血液微采样设备的挑战。之后，我们讨论了基于被动流动的设计的最新进展，以克服当前 DBS 血液微采样的这些挑战。最后，我们介绍了 DBS 在临床和非临床研究中的一些应用。这篇综述将使从事复杂流体流动、表面化学以及生物医学和生物学应用的材料和设备设计的研究人员受益。
