Nanowire array chips for molecular typing of rare trafficking leukocytes with application to neurodegenerative pathology

Abstract

Despite the presence of the blood-brain barrier (BBB) that restricts the entry of immune cells and mediators into the central nervous system (CNS), a small number of peripheral leukocytes can traverse BBB and infiltrate into the CNS. Cerebrospinal fluid (CSF) is one of the major routes through which trafficking leukocytes migrate into the CNS. Therefore, the number of leukocytes and their phenotypic compositions in CSF may represent important sources to investigate immune-to-brain interaction, or diagnose and monitor neurodegenerative diseases. Due to the paucity of trafficking leucocytes in CSF, a technology capable of efficient isolation, enumeration, and molecular typing of these cells in the clinical settings has not been achieved. In this study, we report on a biofunctionalized silicon nanowire array chip for highly efficient capture and multiplexed phenotyping of rare trafficking leukocytes in small quantities (50 microliters) of clinical CSF specimens collected from neurodegenerative disease patients. The antibody-coated 3D nanostructured materials exhibited vastly improved rare cell capture efficiency due to high-affinity binding and enhanced cell-substrate interactions. Moreover, our platform creates multiple cell capture interfaces, each of which can selectively isolate specific leukocyte phenotype. Comparison with the traditional immunophenotyping using flow cytometry demonstrated that our novel silicon nanowire-based rare cell analysis platform can perform rapid detection and simultaneous molecular characterization of heterogeneous immune cells. Multiplexed molecular typing of rare leukocytes in CSF samples collected from Alzheimer’s disease patients revealed the elevation of white blood cell counts and significant alterations in the distribution of major leukocyte phenotypes. Our technology represents a practical tool potentially for diagnosing and monitoring the pathogenesis of neurodegenerative diseases by allowing an effective hematological analysis of CSF from patients.

Oral TNFα Modulation Alters Neutrophil Infiltration, Improves Cognition and Diminishes Tau and Amyloid Pathology in the 3xTgAD Mouse Model

“…Disease conditions and the concomitant rise in cytokines are known to orchestrate an increase in leukocyte extravasation and accumulation in the CNS. Studies in AD patients [ 3 , 4 ] and in AD animal models [ 5 – 7 ] provide evidence for increased trafficking of leukocytes into the brain and interaction with brain resident microglia. Despite general consensus on this increased trafficking, it remains unclear whether this increased infiltration is detrimental to or beneficial for the AD brain.…”

Effect of graphene oxide ratio on the cell adhesion and growth behavior on a graphene oxide-coated silicon substrate

“…Nanostructures such as nanowires, nanopillars, and nanoholes are known to improve cell-capture efficiency by ~20% as reported previously 5 6 7 . This improvement is mainly due to enhanced cell adhesion to nanostructures with higher cell adhesion forces on the surface 6 8 9 10 11 . In addition, cell morphology on nanostructured surfaces can be characterized by the number of filopodia and their morphology 6 9 .…”

Biochips—New Platforms for Cell‐Based Immunological Assays

“…High correlation ( R 2 ≥ 0.89) and high repeatability (CV ≤ 4.7%) of cell counts from the microchip compared with flow cytometry suggest that this microchip platform, which integrates sample preparation on the chip, could be a feasible approach to provide portable and rapid CD4+ and CD8+ T‐cell counts for patients in resource‐limited regions. Affinity‐based isolation of leukocyte subsets was also reported by others, in which one or more leukocyte subsets with high purity were isolated by specific antibodies and counted, or measured for their secretion, or recovered for further analysis …”