Cancer is the second leading cause of death worldwide. Differences in drug resistance and treatment response caused by the heterogeneity of cancer cells are the primary reasons for poor cancer therapy outcomes in patients. In addition, current in vitro anticancer drug-screening methods rely on two-dimensional monolayer-cultured cancer cells, which cannot accurately predict drug behavior in vivo. Therefore, a powerful tool to study the heterogeneity of cancer cells and produce effective in vitro tumor models is warranted to leverage cancer research. Droplet microfluidics has become a powerful platform for the single-cell analysis of cancer cells and three-dimensional cell culture of in vitro tumor spheroids. In this review, we discuss the use of droplet microfluidics in cancer research. Droplet microfluidic technologies, including single- or double-emulsion droplet generation and passive- or active-droplet manipulation, are concisely discussed. Recent advances in droplet microfluidics for single-cell analysis of cancer cells, circulating tumor cells, and scaffold-free/based 3D cell culture of tumor spheroids have been systematically introduced. Finally, the challenges that must be overcome for the further application of droplet microfluidics in cancer research are discussed.

中文翻译：

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用于当前癌症研究的液滴微流体：从单细胞分析到 3D 细胞培养

癌症是全球第二大死亡原因。癌细胞异质性引起的耐药性和治疗反应差异是患者癌症治疗效果不佳的主要原因。此外，目前的体外抗癌药物筛选方法依赖于二维单层培养的癌细胞，无法准确预测药物在体内的行为。因此，需要一个强大的工具来研究癌细胞的异质性并产生有效的体外肿瘤模型，以利用癌症研究。液滴微流控已成为癌细胞单细胞分析和体外肿瘤球体三维细胞培养的强大平台。在这篇综述中，我们讨论了液滴微流体在癌症研究中的应用。简要讨论了液滴微流体技术，包括单乳液或双乳液液滴生成以及被动或主动液滴操纵。系统介绍了用于癌细胞、循环肿瘤细胞的单细胞分析的液滴微流控以及肿瘤球体的无支架/基于3D细胞培养的最新进展。最后，讨论了液滴微流控在癌症研究中进一步应用必须克服的挑战。