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Development of lab-on-a-chip acoustofluidic platform with a potential application in extracellular vesicles purification

University of British Columbia

Extracellular vesicles (EVs) play an important role in intercellular communication, as they are responsible for the transportation of proteins from their cells of origin to other locations within the body. They are found in a variety of bodily fluids and have proven to be promising candidates for the early diagnosis of different types of diseases. To use EVs as diagnostic tools their purification is a prerequisite step. Traditional methods of EV purification are time-consuming and expensive and can lead to morphology disruptions due to high induced shear stress. To address these problems, novel lab-on-a-chip-based purification methods have been employed. Among various methods introduced for separation and purification of EVs, cells, and synthetics microparticles, acoustofluidics (i.e., a combination of microfluidics and acoustics) has been one of the most effective methods. Unlike common separation techniques carried out in clinical laboratories that are based on chemical properties, the acoustofluidic process relies on the physical properties of the sample. Using acoustofluidics, the manipulation of cells and microparticles can be achieved in a label-free, contact-free, and highly biocompatible manner. This thesis reviews two types of acoustofluidic platforms which work based on parallel standing surface acoustic wave (pSSAW) and tilted standing surface acoustic wave (tSSAW). pSSAW is mainly used for microparticle alignments while tSSAW is implemented for microparticle separation based on particle size differences. In order to optimize the functionality of the aforementioned platforms, a two-dimensional numerical simulation has been established in this thesis. Such a model has subsequently followed by an experimental test using the pSSAW method. The numerical simulation is used to investigate the effects of the platform geometrical and operational conditions on the separation efficiency. Next, the optimal values are tested in an experimental setting to validate the optimal parameters and conditions. A similar experimental approach is applied to design and test the tSSAW platform although numerical simulation cannot be developed as such geometry requires three-dimensional modeling which is computationally expensive. Using the tSSAW chip, a separation efficiency of > 90% is demonstrated for the separation of 0.6 μm microparticles from 15 μm and 20 μm microparticles by adjusting the operational conditions.

Text

2021-01-01

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/72929

Mechanical Engineering

University of British Columbia

UBCO

http://creativecommons.org/licenses/by-nc-nd/4.0/