Microfluidic-based isolation of circulating tumor cells with high-efficiency and high-purity

The isolation of circulating tumor cells (CTCs) from complex biological samples is of paramount significance for advancing cancer diagnosis, prognosis, and treatment. However, the low concentration of CTCs and nonspecific adhesion of white blood cells (WBCs) present challenges that hinder the efficiency and purity of captured CTCs. Microfluidic-based strategies utilize precise fluid control at the micron level to incorporate specific micro/nanostructures or recognition molecules, enabling effective CTCs separation. Moreover, by employing surface modification designs that exhibit exceptional anti-adhesion properties against WBCs, the purity of isolated CTCs can be further enhanced. This review offers an in-depth exploration of recent advancements, challenges, and opportunities associated with microfluidic-based CTCs isolation from biological samples. Firstly, we will comprehensively introduce the microfluidic-based strategies for achieving high-efficiency CTCs isolation, which includes the morphological design of microchannels for physical force-based CTCs isolation and the specific modification of microchannel surfaces for affinity-based CTCs isolation. Subsequently, a review of recent research advances in microfluidic-based high-purity CTCs isolation is presented, focusing on strategies that decrease the nonspecific adhesion of WBCs through surface micro-/nanostructure construction or chemical and biological modification. Finally, we will summarize the article by providing the prospective opportunities and challenges for the future development of microfluidic-based CTCs isolation.