J. Striebel, M. Vorobii, R. Kumar, H.-Y. Liu, B. Yang, C. Weishaupt, C. Rodriguez-Emmenegger, H. Fuchs, M. Hirtz, K. Riehemann

Adv. NanoBiomed Res. 1 (2021) 2000029

Macrophages will play an important role in future diagnostics and immuno‐therapies of cancer. However, this demands to selectively capture and sort different subpopulations, which remains a challenge due to their innate ability to bind to a wide range of interfaces indiscriminately. The main obstacle here is the lack of interfaces combining sufficient antifouling properties with the display of specific binding sites allowing sorting and quantification. In the present work, we introduce as a proof of principle means to pattern interfaces to locally and selective capture macrophages. The repellent coating is based on antifouling polymer brushes, which can be functionalized. Arrays of binding sites are constructed by microchannel cantilever spotting. Those structures were tested for the isolation of different macrophage subtypes, especially polarized anti‐inflammatory macrophages of the M2 type which can be found associated to tumors (“tumor associated macrophages”; TAMs). Using macrophages as a model system, it was demonstrated that the newly developed surfaces and patterns are efficient for specifically trapping targeted cells and could be useful for further development of therapeutic or diagnostic purposes in the future.