A Novel Cell Release Method for Affinity-based Cell Separation

1134148 Shen化学和生物分离项目的NSF奖项支持Wei Shen教授开发一种新型平台的工作，该平台可以以最小的生物化学和生物物理干扰有效分离亲和捕获的细胞。细胞分离在许多临床实践和生物医学研究中是必不可少的，从疾病诊断和预后到基于细胞的治疗和干细胞生物学的基础研究。由细胞表面生物标志物和固定在材料上的互补配体之间的亲和力介导的细胞分离是无标记的和高度特异性的，因此特别有吸引力。然而，由于细胞-材料相互作用的多价性质，该方法受到难以有效分离处于存活和未扰动状态的捕获细胞的限制。虽然这种限制对于诊断和预后应用不是问题，但当需要分离和回收稀有敏感细胞以用于未受干扰和功能状态时，例如基于干细胞的治疗，这是一个重大挑战。为了充分释放无标记、基于亲和力的细胞分离的潜力，必须开发新的细胞分离方法。在这个项目中，我们将利用生物聚合物的自组装，在细胞捕获后将聚乙二醇（PEG）带到材料表面，这样多价细胞-基质相互作用就可以被破坏，从而有效释放亲和捕获的细胞，这是由于延长的PEG链的构象能。该项目的成功完成将导致一种新的细胞分离方法，该方法与无标记和高度特异性的亲和捕获一起，将允许以前所未有的集体质量进行细胞分离，即高特异性，高产率和对细胞的最小扰动。该细胞分离平台可以容易地适用于基于各种细胞表面生物标志物的亲和细胞分离。该方法与各种形式的细胞分离兼容：微流体装置中的小规模操作或大规模亲和色谱;平坦的亲和基底或基于珠的亲和基质。该项目将为研究生和本科生提供跨学科的培训机会。这种培训机会对于培养生物医学工程领域的合格劳动力非常重要，这是医疗保健行业的主要驱动力之一。通过这个项目，PI将通过各种方案促进本科生的研究活动，特别是代表性不足的少数民族和女学生。PI将参与K-12外展活动，以激发年轻学生对生物分子工程，生物材料工程和再生医学的兴趣，并激励更多学生在这些领域从事职业。

1134148ShenThis NSF award by the Chemical and Biological Separations program supports work by Professor Wei Shen to develop a novel platform to efficiently detach affinity-captured cells with minimal biochemical and biophysical perturbation. Cell separation is essential in many clinical practices and biomedical studies, ranging from disease diagnosis and prognosis to cell-based therapy and fundamental investigations of stem cell biology. Cell separation mediated by the affinity between a cell surface biomarker and a complementary ligand immobilized on a material is label-free and highly specific, and therefore is particularly attractive. However, this method has been limited by the difficulty in efficiently detaching captured cells in a viable and unperturbed state due to the multivalent nature of cell-material interactions. Although this limitation is not an issue for diagnostic and prognostic applications, it is a major challenge when rare, sensitive cells need to be isolated and recovered for use in an unperturbed and functional state, such as stem-cell-based therapy. To fully unleash the potential of label-free, affinity-based cell separation, new cell detachment methods must be developed. In this project, we will harness self-assembly of biopolymers to bring polyethylene glycol (PEG) to the material surface after cell capture, so that multivalent cell-substrate interactions can be disrupted for efficient release of affinity-captured cells due to the conformational energy of extended PEG chains. Successful completion of this project will lead to a novel cell detachment method that, together with label-free and highly specific affinity capture, will allow cell separation to be performed with unprecedented collective quality in terms of high specificity, high yield, and minimal perturbation on cells. This cell detachment platform can be readily adapted for affinity cell separation based on various cell surface biomarkers. The method is compatible with various formats of cell separation: either small-scale operation in microfluidic devices or large-scale affinity chromatography; either flat affinity substrates or bead-based affinity matrices. This project will provide interdisciplinary training opportunities for graduate and undergraduate students. Such training opportunities are important for preparing a qualified workforce in the field of biomedical engineering, which is one of the major driving forces for the health care industries. Through this project, the PI will promote the research activities of undergraduate students, in particular underrepresented minority and women students, in her laboratory through various programs. The PI will participate in K-12 outreach activities to stimulate interest in biomolecular engineering, biomaterials engineering, and regenerative medicine among young students and inspire more students to pursue careers in these fields.