Integrative Magneto‐Microfluidic Separation of Immune Cells Facilitates Clinical Functional Assays

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2023-10, Vol.19 (43), p.e2302809-n/a
• Main Authors: Shin, Hee Sik, Park, Jeehun, Lee, Seung Yeop, Yun, Hyo Geun, Kim, Byeongyeon, Kim, Jinho, Han, Sangbin, Cho, Duck, Doh, Junsang, Choi, Sungyoung
• Format: Article
• Language: English
• Subjects: Abnormalities; Buffers; degas‐driven pumping; Diagnosis; Erythrocytes; functional immune cell assay; Immune system; Immunology; magnetic field‐enhanced microstructures; Microfluidic devices; microfluidic lattice; Nanotechnology; natural killer cell separation; Polydimethylsiloxane; Separation; Workflow
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202302809

Accurately analyzing the functional activities of natural killer (NK) cells in clinical diagnosis remains challenging due to their coupling with other immune effectors. To address this, an integrated immune cell separator is required, which necessitates a streamlined sample preparation workflow including immunological cell isolation, removal of excess red blood cells (RBCs), and buffer exchange for downstream analysis. Here, a self‐powered integrated magneto‐microfluidic cell separation (SMS) chip is presented, which outputs high‐purity target immune cells by simply inputting whole blood. The SMS chip intensifies the magnetic field gradient using an iron sphere‐filled inlet reservoir for high‐performance immuno‐magnetic cell selection and separates target cells size‐selectively using a microfluidic lattice for RBC removal and buffer exchange. In addition, the chip incorporates self‐powered microfluidic pumping through a degassed polydimethylsiloxane chip, enabling the rapid isolation of NK cells at the place of blood collection within 40 min. This chip is used to isolate NK cells from whole blood samples of hepatocellular cancer patients and healthy volunteers and examined their functional activities to identify potential abnormalities in NK cell function. The SMS chip is simple to use, rapid to sort, and requires small blood volumes, thus facilitating the use of immune cell subtypes for cell‐based diagnosis. A self‐powered integrated microfluidic chip is presented that combines all necessary microfluidic elements for pump‐free, on‐chip immuno‐separation of target cells from whole blood, enabling rapid separation of natural killer cells and facilitating rapid examination of their functional status in hepatocellular cancer patients.