Patient-centric devices for sample preparation and analysis using capillary microfluidics
Time: Fri 2026-11-06 10.00
Location: Q1, Malvinas väg 4, Stockholm
Video link: https://kth-se.zoom.us/j/66913270315
Language: English
Subject area: Electrical Engineering
Doctoral student: Carl Olsson , Mikro- och nanosystem
Opponent: Professor Manabu Tokeshi, Hokkaido University, Sapporo, Japan
Supervisor: Professor Niclas Roxhed, Mikro- och nanosystem; Professor em Olof Beck, Karolinska institutet, Stockholm, Sweden; Docent Lena Backlund, Karolinska institutet, Stockholm, Sweden; Professor Martin Schalling, Karolinska institutet, Stockholm, Sweden
QC 20261007
Abstract
Blood sampling is an essential component of modern healthcare. However, due to the centralized nature of blood processing and analysis, it typically requires patients to visit a hospital or clinical laboratory. Patient-centric testing (PCT), including patient-centric sampling (PCS) and point-of-care (POC) testing, seeks to reduce this burden by simplifying sample collection, processing, and analysis. By lowering the barriers associated with blood testing, these approaches have the potential to improve accessibility for patients while reducing workload within healthcare systems.
Blood is a complex biological fluid containing a wide range of cellular and molecular components, many of which require specific processing prior to analysis. Consequently, the analytical requirements vary considerably between different biomarkers, creating a challenge for the development of PCS and POC testing technologies.
This thesis presents novel approaches for therapeutic drug monitoring (TDM) of lithium, the first-line treatment for bipolar disorder. Lithium therapy requires regular monitoring due to its narrow therapeutic window and risk of toxicity, resulting in repeated hospital or clinic visits for blood sampling and serum lithium analysis. Two approaches are investigated to simplify monitoring. First, volumetric dried blood spots (DBS) are evaluated as a patient-centric home-sampling method through the development of an elution and analytical protocol for lithium determination from volumetric DBS samples, followed by a longitudinal clinical study comparing DBS-based measurements with conventional clinical analyses. Second, a POC device concept for lithium monitoring based on on-chip serum separation and colorimetric detection is developed and evaluated in patients to assess both the technical feasibility of the approach and patient interest in simplified testing methods.
In addition, this thesis evaluates a capillary-driven microfluidic device designed to process whole blood into a nanofiltrate. The device utilizes a dual-filtration strategy combined with wedge-induced filtration to extract nanoparticles from whole blood. Filtration performance was assessed using nanoparticles, liposomes, and synthetic extracellular vesicles (EV), and the biological characteristics of the resulting nanofiltrate were compared with ultracentrifugation. The device was evaluated using samples from healthy controls and cancer patients. Nanofiltrates from healthy controls were characterised using EV protein profiling, whereas samples from cancer patients were evaluated for downstream analysis of circulating tumour DNA, cell-free DNA, and copy number variations.
Overall, this work presents novel approaches for lithium monitoring and blood sample processing. These technologies have the potential to reduce barriers to therapeutic drug monitoring, improve accessibility to lithium treatment, and facilitate downstream analysis of blood biomarkers.