Enhancing single-cell encapsulation in droplet microfluidics with fine-tunable on-chip sample enrichment  

作　　者：Tao Tang Hao Zhao Shaofei Shen Like Yang Chwee Teck Lim 

机构地区：[1]Department of Biomedical Engineering,National University of Singapore,117583 Singapore,Singapore [2]Integrative Sciences and Engineering Programme,NUS Graduate School,National University of Singapore,119077 Singapore,Singapore [3]Shanxi Key Lab for Modernization of TCVM,College of Life Science,Shanxi Agricultural University,Taigu,Shanxi 030801,China [4]Institute for Health Innovation&Technology,National University of Singapore,117599 Singapore,Singapore [5]Mechanobiology Institute,National University of Singapore,117411 Singapore,Singapore [6]Institute for Digital Molecular Analytics and Science,Nanyang Technological University,636921 Singapore,Singapore

出　　处：《Microsystems & Nanoengineering》2024年第1期149-160,共12页微系统与纳米工程（英文）

摘　　要：Single-cell encapsulation in droplet microfluidics is commonly hindered by the tradeoff between cell suspension density and on-chip focusing performance.In this study,we introduce a novel droplet microfluidic chip to overcome this challenge.The chip comprises a double spiral focusing unit,a flow resistance-based sample enrichment module with fine-tunable outlets,and a crossflow droplet generation unit.Utilizing a low-density cell/bead suspension(2×10^(6) objects/mL),cells/beads are focused into a near-equidistant linear arrangement within the double spiral microchannel.The excess water phase is diverted while cells/beads remain focused and sequentially encapsulated in individual droplets.Focusing performance was assessed through numerical simulations and experiments at three flow rates(40,60,80μL/min),demonstrating successful focusing at 40 and 80μL/min for beads and cells,respectively.In addition,both simulation and experimental results revealed that the flow resistance at the sample enrichment module is adjustable by punching different outlets,allowing over 50%of the aqueous phase to be removed.YOLOv8n-based droplet detection algorithms realized the counting of cells/beads in droplets,statistically demonstrating single-cell and bead encapsulation rates of 72.2%and 79.2%,respectively.All the results indicate that this on-chip sample enrichment approach can be further developed and employed as a critical component in single-cell encapsulation in water-in-oil droplets.

关 键 词：BEADS OUTLET sample 

分 类 号：Q2[生物学—细胞生物学]