Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education, School of Physics and Technology , Wuhan University , Wuhan 430072 , China.
Research Center for Tissue Engineering and Regenerative Medicine, Union Hospital, Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430022 , China.
ACS Appl Mater Interfaces. 2019 Nov 6;11(44):41118-41126. doi: 10.1021/acsami.9b16566. Epub 2019 Oct 25.
The recovery of rare single circulating tumor cells (CTCs) from patients has great potential to facilitate the study of cell heterogeneity and cancer metastasis, which may promote the development of individualized cancer immunotherapy. Herein, a versatile single-cell recovery approach that utilizes an acoustic droplet-induced enzyme responsive platform for the capture and on-demand release of single CTCs is proposed. The platform combines a multifunctional enzyme-responsive gelatin nanoparticle (GNP)-decorated substrate (GNP-chip) for specific capture with an acoustic droplet positioning technique to realize on-demand release of single CTCs. The acoustic droplet dispenser is employed to generate oxidized alginate microdroplets containing the MMP-9 enzyme (OA-MMP-9) with controllable size and precise positioning upon the cell-attached GNP-chip, allowing controlled cell-surface biodegradation under enzymatic reactions followed by calcium chloride (CaCl) solution treatment to form single-cell encapsulated calcium alginate hydrogels. Benefitting from the existence of hydrogels, the released cells could be efficiently recovered by microcapillary. Results demonstrate that the encapsulated cells maintain good cell morphology in the hydrogels, which allow further single-cell nucleic acid analysis. As a proof-of-concept platform, this approach enables reliable and efficient retrieval of single CTCs and holds the potential for versatility in single-cell analysis systems.
从患者中回收罕见的单个循环肿瘤细胞（CTC）具有极大的潜力来促进对细胞异质性和癌症转移的研究，这可能会推动个体化癌症免疫疗法的发展。在此，提出了一种通用的单细胞回收方法，该方法利用声滴诱导酶响应平台来捕获和按需释放单个 CTC。该平台结合了一种多功能酶响应明胶纳米颗粒（GNP）修饰基底（GNP-芯片）用于特异性捕获，以及声滴定位技术来实现单个 CTC 的按需释放。声滴分配器用于生成含有 MMP-9 酶的氧化海藻酸钠微滴（OA-MMP-9），其尺寸可控且可精确定位在细胞附着的 GNP-芯片上，允许在酶反应下进行受控的细胞表面生物降解，随后用氯化钙（CaCl）溶液处理形成单细胞包封的海藻酸钙水凝胶。得益于水凝胶的存在，释放的细胞可以通过微毛细管有效地回收。结果表明，包封的细胞在水凝胶中保持良好的细胞形态，这允许进一步进行单细胞核酸分析。作为概念验证平台，该方法能够可靠且高效地回收单个 CTC，并在单细胞分析系统中具有多功能性的潜力。
