Investigating Biomechanical Behaviors of Single Cells Using Micro-engineered Systems

Abstract

Developing micro engineered systems is critical for characterizing the micro-scale biomechanical properties of biomolecules and biological cells. In this thesis, two different micro engineered systems are introduced: 1) a micro cytometer for comprehensively characterizing biomechanical and biochemical properties of single floating cells and 2) a cell – matrix hybrid micro system for inspecting cell contractility-related behaviors. To develop a practical micro cytometry for analyzing liquid biopsies, micro confining channel arrays are embedded into a microfluidic chip such that the cell deformation can be controlled by the microscale fluidic flows. And a multiplexed phenotypic profiling scheme based on the cell deformation is introduced to characterize both biomechanical and biochemical properties of single floating cells. In the meanwhile, by analyzing transient deformations of cells along a confining channel, the viscoelastic properties of floating single cells are illustrated. The mechanical properties of the largely deformed cells are further revealed by a modified contact model. A cell – ECM hybrid micro system is developed by applying the contractility of biological cells. Various micro contact printing techniques are introduced to fabricate patterned surfaces, in which cells actively interact with the ECM patterns and remodel the ECM patterns by a mechanism related to the cell traction forces. Following the investigation of cell interacting with ECM protein on a substrate, one of the cell active behaviors, i.e. cell spreading, is characterized by a viscoelastic cell spreading model. These micro systems will facilitate the researches in liquid biopsy based cancer diagnostics, new biomarker identification and tissue engineering.

Date of Award	7 Dec 2017
Original language	English
Awarding Institution	City University of Hong Kong
Supervisor	Hiu Wai Raymond LAM (Supervisor)