Microfluidic Chip for Cryopreservation of Blood Cells

描述（由申请人提供）：我们建议开发一种自动化微流控微芯片，结合高通量细胞封装液滴喷射系统，用于高效、快速、廉价的血液冷冻保存。血液是生物保存最重要的组织。特别是，当患者因以下原因大量失血时，需要输血红细胞：(1)创伤；(2)出血性疾病；（三）大手术；或(4)产后出血。目前的技术只允许冷冻储存血液和血液制品，包括包装红细胞。目前的血液冷冻技术采用劳动和时间密集的程序，需要训练有素的临床技术人员。血液生物保存涉及复杂的人工处理，导致高成本、长处理时间和过程可变性。目前，血细胞的低温保存主要是通过慢速冷冻来完成的。然而，缓慢的冷冻使血细胞容易受到细胞内冰晶形成（IIF）造成的细胞内损伤。因此，迫切需要改进技术，使血液能够有效地冷冻保存。尽管文献显示玻璃化技术可以对各种类型的细胞（如红细胞和卵母细胞）获得更好的生物保存结果，但由于通量限制，玻璃化技术尚未应用于临床血液生物保存。目前的玻璃化方法需要将微升体积的细胞填充到吸管中，然后玻璃化，这对于生物储备升的血液是不可行的。由于这些产品的保质期有限，血液冷冻必须在美国的每家医院和医疗中心持续和常规地进行，以满足持续的需求。因此，需要一种新的平台技术来改变现有血液供应链机制的运营物流，以实现高效的未来。在这个项目中，我们将利用玻璃化技术提供的优势和我们新颖的微型技术来推进血液冷冻保存的临床实践。因此，我们期望实现：在低冷冻保护剂浓度和低冰形成水平下的超高速冷却速率（10,000℃/秒）。这些条件将改善红细胞的功能，延长红细胞的保质期（约42天）。我们建议开发一个几乎适用于所有细胞类型的平台，特别是治疗性红细胞、外周血干细胞和原代肝细胞。如果这项研究成功，将对民用和军用血液制品的长期储存产生重大影响。

DESCRIPTION (provided by applicant): We propose to develop an automated microfluidic microchip merged with a high-throughput cell- encapsulating droplet ejection system for efficient, rapid, and inexpensive blood cryopreservation. Blood is the single most important tissue for biopreservation. In particular, red blood cells (RBCs) are required for transfusion, whenever patients suffer massive blood loss due to: (1) trauma; (2) bleeding disorders; (3) major surgery; or (4) post-partum hemorrhage. Current technology only allows frozen storage of blood and blood products, including packed RBCs. Current blood-freezing technologies employ labor and time intensive procedures that require trained clinical technicians. The complex manual handling involved in blood biopreservation results in high cost, long-processing times, and process variability. Currently, cryopreservation of blood cells is mostly done by slow-freezing. However, slow freezing leaves blood cells susceptible to intracellular damage from intracellular ice crystal formation (IIF). Therefore there is a significant need for improved technologies enabling effective cryopreservation of blood. Although it is shown in the literature that vitrification techniques could achieve better biopreservation outcomes for various cell types such as RBCs and oocytes, vitrification is not applied to blood biopreservation clinically due to throughput limitations. The current vitrification methods require microliter volumes of cells to be filled into straws that are then vitrified, which is not feasible to biopreserve liters of blood. Since these products have limited shelf lives, blood freezing must be done continually and routinely in every hospital and medical center in the US to meet the constant demand. Accordingly, there is a need for a new platform technology that will transform the operational logistics for an efficient future for the existing blood supply chain mechanisms. In this project, we will advance the clinical practice in blood cryopreservation by leveraging the advantages provided by vitrification and enabled by our novel microscale technologies. As a result we expect to achieve: ultra-rapid cooling rates (10,000 oC/sec) at low cryoprotectant agent concentrations with low levels of ice formation. These conditions will lead to improved functionality and longer shelf life of RBCs (>42 days). We are proposing to develop an enabling platform applicable to practically all cell types, especially therapeutic RBCs, peripheral blood stem cells, and primary hepatocytes. If successful, the proposed research can have a significant impact on the long-term storage of blood products for both civilian and military needs. PUBLIC HEALTH RELEVANCE: We apply nano- and micro-scale technologies to develop a novel closed system for automated blood cryopreservation. Such a technology would have a significant clinical impact on blood banking, storage and transportation.