Multistage Separation of Cells using Hydrophobic Interactions Enabled by Temperature-Responsive Polymers

1264024 Gao拟议工作的目标是开发一种多级细胞分离技术，以克服使用温度敏感聚合物和多次温度循环的非特异性相互作用引起的选择性问题。 一种简单而快速的细胞分离方法是用一种选择性捕获靶点的受体将磁性颗粒（MNP）功能化，然后通过施加磁场将MNP从混合物中去除。 磁性分离的效率通常受到MNP和非靶物质之间的非特异性相互作用的限制。 为了克服目前单级磁分离技术中非特异性相互作用造成的低效率，PI旨在开发一种类似于多级蒸馏的多级细胞分离技术。 其关键思想是通过操纵MNP和细胞之间的疏水相互作用来允许MNP捕获和释放靶细胞。 这一过程将通过将温度响应性聚合物附着到MNP和靶细胞上来实现。 通过温度循环，其触发聚合物的可逆的疏水-疏水相变，靶细胞可以被MNP以比非靶细胞更高的效率可逆地捕获和释放（由于疏水相互作用）。 在单个循环中靶细胞与非靶细胞的捕获和释放效率的差异将通过多个分离阶段放大。 假设多级分离过程将能够有效地规避由当前单级磁性细胞分离过程中的非特异性相互作用引起的问题。 PI将（i）构建一个平台来实现所提出的多级细胞分离方案，（ii）测试该方案能够克服非特异性相互作用导致的低效率的假设，以及（iii）开发设计多级细胞分离过程的一般原则，为多级蒸馏过程开发指导建模工具。 更广泛的影响。 这项技术可能会在医疗诊断和治疗、环境监测和国土安全方面得到应用。 作为教育使命的一部分，该项目将通过以下方式整合研究和教育：（i）为研究生和本科生提供化学工程、材料和表面科学以及生物化学交叉学科的培训，（ii）为化学工程教育中的多级分离课程开发新材料，通过将既定的化学工程原理应用于新兴领域，突出可能的创新，（iii）通过匹兹堡大学现有的招募和留住代表性不足的学生的计划，增加代表性不足的群体对研究的参与;（iv）通过与匹兹堡卡内基科学中心的合作，向K-12学生推广。

1264024 GaoThe goal of the proposed work is to develop a multistage cell separation technique to overcome selectivity problems caused by non-specific interactions using temperature-sensitive polymers and multiple temperature cycling. A simple and rapid method for separation of cells is to functionalize magnetic particles (MNPs) with a receptor that selectively captures the target and then remove the MNPs from the mixture by applying a magnetic field. The efficiency of magnetic separation is typically limited by the non-specific interaction between the MNPs and non-target species. To overcome the inefficiencies caused by non-specific interactions in current single-stage magnetic separation techniques, the PI aims to develop a multistage cell separation technique that is analogous to multistage distillation. The key idea is to allow the MNPs capture and release the target cells by manipulating the hydrophobic interaction between the MNPs and the cells. This process will be enabled by attaching temperature-responsive polymers to both the MNPs and the target cells. Through temperature cycling, which triggers the reversible hydrophilic-to-hydrophobic phase transition of the polymers, the target cells can be reversibly captured and released by the MNPs (due to hydrophobic interaction) at a higher efficiency than the non-target cells. The difference in the capture-and-release efficiencies of target cells versus non-target cells in a single cycle will be amplified by multiple separation stages. The hypothesis is that a multistage separation process will be able to effectively circumvent the problem caused by the non-specific interactions in the current single-stage magnetic cell separation process. The PI will (i) construct a platform to realize the proposed multistage cell separation scheme, (ii) test the hypothesis that this scheme is able to overcome the inefficiencies caused by non-specific interactions, and (iii) develop general principles for designing multistage cell separation processes, guided modeling tools developed for multistage distillation processes. Broader Impacts. The proposed technology may find applications in medical diagnostics and therapeutics, environmental monitoring, and homeland security. As part of the educational mission, this project will integrate research and education by (i) providing training for graduate and undergraduate students at the crossroads of chemical engineering, materials and surface science, and biochemistry, (ii) developing new materials for the multistage separation course in chemical engineering education, highlighting possible innovations by applying established chemical engineering principles to emerging fields, (iii) increasing the participation of underrepresented groups in research through established programs for recruitment and retention of underrepresented students at the University of Pittsburgh, and (iv) outreach to K-12 students through collaboration with Carnegie Science Center in Pittsburgh.