CAREER: An electrokinetically driven micro-device for rapid purification and characterization of exosomes

癌症是全球发病率和死亡率的主要原因之一，但约46%的患者放弃常规筛查，因为这些程序的侵入性，包括组织活检。因此，在基础和临床研究中有显著的努力来开发液体活检，一种用于检测来自生物流体的循环生物标志物的微创范例。在循环生物标志物中，外泌体，细胞释放的帮助细胞相互交流的小颗粒，引起了人们的极大关注。外泌体在包括血液、唾液和尿液在内的所有生物流体中都非常丰富，它们可以为释放它们的细胞类型（如肿瘤细胞）提供关键信息。然而，使用外泌体作为癌症和其他疾病的生物标志物一直具有挑战性，因为缺乏一种可以以具有成本效益和及时的方式可靠地分离和表征外泌体的技术。 这项研究将导致一种快速准确的微制造设备，可以快速，廉价地纯化和表征生物流体中的外泌体，基于它们的电特性。该项目的直接重点是分离和表征与癌症相关的外泌体;然而，外泌体与许多其他疾病有关，包括糖尿病，心血管疾病，传染病和神经退行性疾病。因此，这种新型设备可用于广泛的医学诊断和生物医学研究，可能为患者提供频繁，负担得起的早期测试。此外，这个跨学科项目跨越了电气工程，微/纳流体，生物学和物理学之间的传统界限，这将为学生在学术培训期间提供独特的教育体验。该项目将通过令人难忘和令人兴奋的动手项目和积极的学习经验，使K-12学生接触生物医学微系统领域。该教育计划将通过“妇女参与科学和工程”方案，招聘和培训女科学家和女工程师，扩大代表性不足群体学生的参与。这些本科生将与研究生密切合作进行这项研究，他们将由主要研究者指导。该项目还将通过YouTube频道和“ThinkTV”节目向公众宣传微纳米技术如何促进医学发展，该节目将在俄亥俄州西南部播出。外泌体（30-150 nm）从许多细胞类型释放到细胞外空间，分布在所有生物流体中。它们的区室组成和功能取决于原始细胞类型，并且它们在细胞-细胞通讯中作为分子货物发挥重要作用。肿瘤来源的外泌体在液体活检中具有作为循环生物标志物的潜在用途，用于早期诊断和难以进入肿瘤部位的癌症进展的常规临床监测。然而，由于外来体的异质性和生物样品的复杂性，快速有效地检测外来体是具有挑战性的。这个CAREER项目的最终目标是研究使用间接介电电泳（DEP）和阻抗探测来纯化和鉴定来自生物流体的循环癌症来源的外泌体。 这项研究将采用一种新型的芯片DEP设备从生物流体中分离外来体，并在宽频谱（500 KHz-50 MHz）上测量它们的电阻抗，以确定它们的介电特性。然后，外泌体的介电性质将与其分子含量、生化性质和促炎反应方面的功能相关。这项研究最终可以在临床环境中实现微创液体活检。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Cancer is among the leading causes of morbidity and mortality worldwide, yet about 46% of patients forsake routine screening because of the invasive nature of such procedures, including tissue biopsy. Therefore, there are significant efforts in basic and clinical research to develop a liquid biopsy, a minimally invasive paradigm for the detection of circulating biomarkers from biofluids. Among circulating biomarkers, exosomes, small particles released by cells that help cells communicate with each other, have drawn a great deal of attention. Exosomes are highly abundant in all biofluids including blood, saliva and urine, and they can provide crucial information to the type of cell, such as a tumor cell, that released them. However, using exosomes as biomarkers for cancer and other diseases has been challenging due to the lack a technology that can reliably isolate and characterize exosomes in a cost-effective and timely manner. This research will lead to a rapid and accurate micro-fabricated device that can quickly and cheaply purify and characterize exosomes from biofluids based on their electrical properties. The immediate focus of this project is to isolate and characterize exosomes related to cancer; however, exosomes are associated with many other diseases, including diabetes, cardiovascular disease, infectious diseases and neurodegenerative disorders. Thus, this novel device could be utilized for a wide range of medical diagnoses and biomedical research, potentially providing frequent, affordable, and early testing for patients. Furthermore this interdisciplinary project crosses the traditional boundaries between electrical engineering, micro/nanofluidics, biology and physics, which will provide students with a unique educational experience during their academic training. This project will expose K-12 students to the field of biomedical microsystems through memorable and exciting hands-on projects and active learning experiences. The education plan will broaden the participation of students from underrepresented groups by recruiting and training female scientists and engineers through the Women in Science and Engineering (WISE) program. These undergraduate students will work closely with graduate students to conduct this research, and they will be mentored by the principal investigator. This project will also educate the public about how micro-nanotechnologies can advance medicine through a YouTube channel and “ThinkTV” program, which will be broadcast in Southwest Ohio.Exosomes (30–150 nm) are released from many cell types into the extracellular space, are distributed in all biofluids. Their compartmental composition and function depend on the originating cell type and they play an important role as a molecular cargo in cell-cell communication. Tumor-derived exosomes have potential use as circulating biomarkers in liquid biopsy for early stage diagnostics and routine clinical monitoring of cancer progression in difficult to access tumor sites. However, rapid and efficient detection of exosomes is challenging owing to their heterogeneity and the complexity of biological samples. The ultimate goal of this CAREER project is to investigate the use of indirect dielectrophoresis (DEP) and impedance probing to purify and identify circulating cancer-derived exosomes from biofluids. This research will employ a novel DEP device on chip to isolate exosomes from biofluids and measure their electrical impedance over a wide frequency spectrum (500 KHz-50 MHz) to establish their dielectric properties. The dielectric properties of the exosomes will then be correlated with their molecular content, biochemical properties, and functionalities in terms of pro-inflammatory responses. This research could ultimately enable minimally invasive liquid biopsies in a clinical setting. It could also open a new avenue for diagnostics and personalized therapeutics based on the ability to quickly isolate and analyze exosomes based on their dielectric properties.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.