Date

2016

Document Type

Dissertation

Degree

Doctor of Philosophy

Department

Mechanical Engineering

First Adviser

Liu, Yaling

Other advisers/committee members

Voloshin, Arkady; Zhang, Xiaohui; Ou-yang, Daniel

Abstract

With the development of in vitro systems for tissue engineering, various substrates and mechanical stimuli have been utilized to modulate the cell behavior. It’s known that various micropatterns have been fabricated and applied to regulate cell adhesion, morphology and function. Micropatterns created by standard photolithography process are usually rectangular channels with sharp corners (microgrooves) which provide limited control over cells and are not favorable for cell-cell interaction and communication. We propose a new micropattern with smooth wavy surfaces (micro-waves) to control the position and orientation of cells. Results showed that cells adhered to the wavy surface displayed both improved alignment and adhesion strength compared to those on the flat surface. Shear flow was further applied to examine the cell adhesion response to the flow. In recent years, nanoparticles (NPs) have gained increasing interest due to its potential use as drug delivery, imaging and diagnostic agents in pharmaceutical and biomedical applications. While lots of cells in vivo are under mechanical forces, little is known about the correlation of the mechanical stimulation and the internalization of NPs into cells. We investigate the effects of applied cyclic strain on NPs uptake by bovine aortic endothelial cells (BAECs). The cyclic strain results in a significant enhancement in NP uptake which increases almost linearly with strain level. In my study, micro-patterned substrates, shear flow and cyclic strain have been applied to investigate the cell behavior including cell alignment, cell spreading, cell adhesion and cellular uptake of NPs. Studies of cells response to these mechanical stress promote our current understanding of how cells sense and response to their mechanical environment.

Share

COinS