Detection of detached fetal nucleated red blood cells (fNRBCs) in the maternal peripheral blood may serve as a prospective testing method competing with the cell-free DNA, in non-invasive prenatal testing (NIPT). Methods: Herein, we introduce a facile and effective lab-on-a-chip method of fNRBCs detection using a capture-releasing material that is composed of biotin-doped polypyrrole nanoparticles. To enhance local topographic interactions between the nano-components and fNRBC, a specific antibody, CD147, coated on the nanostructured substrate led to the isolation of fNRBCs from maternal peripheral blood. Subsequently, an electrical system was employed to release the captured cells using 0.8 V for 15 s. The diagnostic application of fNRBCs for fetal chromosomal disorders (Trisomy 13/21/18/X syndrome, microdeletion syndrome) was demonstrated. Results: Cells captured by nanostructured microchips were identified as fNRBCs. Twelve cases of chromosomal aneuploidies and one case of 18q21 microdeletion syndrome were diagnosed using the fNRBCs released from the microchips. Conclusion: Our method offers effective and accurate analysis of fNRBCs for comprehensive NIPT to monitor fetal cell development.
Keywords: chromosomal aneuploidy; fetal nucleated red blood cells; microdeletion syndrome; nanostructure microchip; non-invasive prenatal diagnosis.