University of Illinois Urbana-Champaign

Development of a non-living model system for cell membranes and investigation of its mechanical and tribological properties

Shoaib, Tooba

Content Files
SHOAIB-THESIS-2016.pdf

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https://hdl.handle.net/2142/95436

Description

Title
Development of a non-living model system for cell membranes and investigation of its mechanical and tribological properties
Author(s)
Shoaib, Tooba
Issue Date
2016-07-22
Director of Research (if dissertation) or Advisor (if thesis)
  • Abelson, John R.
  • Espinosa-Marzal, Rosa M.
Department of Study
Materials Science & Engineerng
Discipline
Materials Science & Engr
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
M.S.
Degree Level
Thesis
Date of Ingest
2017-03-01T16:36:31Z
Keyword(s)
  • model cell membrane
  • hydrogel
  • soft matter friction
  • lipid bilayer
  • nanomechanics
Abstract
While our exposure to nanomaterials (NMs) has increased with advancements in nanotechnology, understanding harmful effects of such materials on humans is still wanting. Here we have proposed and developed a non-living model system for cell membranes which is suitable for elucidating interactions between NMs and living cells. In contrast to existing model systems for cell membranes, PAAm hydrogel was used as soft support for the lipid. Grafting of lipid with PAAm was achieved through layer by layer deposition of alternating poly(allylamine hydrochloride) (PAH)and poly(sodium 4-styrenesulfonate) (PSS) polyelectrolyte multilayers (PEM). Single step bilayer formation was observed under QCM on the PAAm-PEM support owing to high electrostatic interactions between the PEM and lipid vesicles with frequency and dissipation changes of ~-30 Hz and ~0.8x10-6, respectively. It is also shown that the PEM architecture is robust and reproducible on gels of different elastic modulus. AFM images confirm bilayer formation on top of PAAm-PEM supports with uniform bilayer patches of ~ 0.5 μm. AFM indentation experiments show significant differences in the elastic modulus and adhesion forces for systems with soft underlying supports compared to systems having a hard substrate. The physiological relevance of the developed system is clear from its mechanical characterization via AFM, where the system undergoes considerable deformation before and after bilayer rupture. This behavior is similar to behavior of real cells, in which deformation of cytoskeleton is dominant over that of the cell membrane. The model cell membrane system was also used to study shear forces at the interface of the lipid bilayer on hydrogel, which gave insights into the frictional behavior of the system and its mechanical interactions with nanoprobes.
Graduation Semester
2016-12
Type of Resource
text
Permalink
http://hdl.handle.net/2142/95436
Copyright and License Information
Copyright 2016 Tooba Shoaib

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Graduate Theses and Dissertations at Illinois
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