17th NARECOM – NAnoEnviCz REsearch COmmunity Meeting
Biosensors for immunocapture of circulating tumor cells will be introduced by Mgr. Jiří Smejkal from the Centre for Nanomaterials and Biotechnology, Faculty of Science, J.E. Purkyně University in Ústí nad Labem.
The 17th NARECOM will take place on Wednesday, May 18, 2022, at 2:30. p.m.
Join Zoom Meeting https://cesnet.zoom.us/j/94040307565
Biosensors for immunocapture of circulating tumor cells
Mgr. Jiří Smejkal
Centre for Nanomaterials and Biotechnology, Faculty of Science, J.E. Purkyně University in Ústí nad Labem, Czech Republic
Cell immunocapture microfluidic devices represent a rapidly developing field with many potential applications in medical diagnostics. Immunocapture of so-called rare cells or circulating tumor cells (CTCs) are typical examples. The core of such approach lies in the cell binding on antibody coated surfaces through their surface receptors. Here we show for the first time, that the small recombinant protein binders (PBs) can be used for this purpose as well with the advantage of their constructional flexibility, possibility of fusion with range of tags or functional proteins and cheap mass production. For this purpose, two different protein binders derived from Albumin Binding Domain (ABDwt) of streptococcal protein G, so called REX and ARS ligands with proved high affinity and selectivity to the human IL-23R and IL-17 receptor A were used. Four PBs variants recognizing two different epitopes on two different receptors and two PBs variants binding to the same epitope on one receptor but having different peptide spacer with Avitag sequence necessary for their immobilization on sensor surface were tested for cell-capture efficiency. The simple glass microfluidic Y-system with planar immunocapture channel working in so-called stop-flow dynamic regime was designed with the possibility to monitor the efficiency of the cell capture by fluorescence microscope. Up to 60-74% efficiency of model THP-1 cells immunocapture on REX/ARS surfaces and practically no cell binding on control ABDwt surfaces was achieved. The role of the epitope, affinity and type of peptide immobilization spacer of PBs as well as the influence of the set stop-flow dynamic conditions on the effectivity of THP-1 cell immunocapture will be discussed in this lecture. Presented results can be further exploited in design of microfluidic devices for rare cells or CTCs immunocapture.