Nanoparticle effects on cell migration

It has been found that gold nanoparticles (Au NPs) are excellent materials for biological applications such as diagnosis and drug delivery, which makes it crucial to understand the interface between gold nanoparticles and cells. Previous work has shown that gold nanoparticles can affect cellular migration, even if outside cells. However, the fundamental of interaction between Au NPs and cells has remained unclear. The most accepted mechanism currently is that by sequestering biomolecules from the environment nanoparticles can change the local molecular concentration, and thus influence cell behavior. Chemotaxis is the movement of cells in response to a chemical stimulus. Chemoattractants are inorganic and organic substances, usually proteins, that create a concentration gradient that attracts cells to move towards them. Chemoattractants are known to be involved in immune responses and wound healing processes in eukaryotic cells. With the presence of chemoattractants, cells move directionally towards the infected sites or wound. Similar processes exist in wound healing. To study the intervention of gold nanoparticles in chemotaxis, two systems were chosen. The first system that was examined in the human monocytes THP-1 cells. As a type of monocyte, THP-1 is known to migrate in response peptide formyl peptides. Another cell/chemoattractant pair that was examined was human dermal fibroblasts (HDF) and platelet-derived growth factor (PDGF). Cells were cultured and placed into 3D collagen gel in a specialized chemotaxis slide, in which a steady chemoattractant concentration was produced. Cell migration was recorded through bright-field optical microscopy. Gold nanospheres with different surface chemistries were introduced into the system. Surface chemistries include cationic PDADMAC, and anionic PSS and citrate. The hypothesis under consideration was that chemoattractant would adsorb mostly strongly to the nanoparticle of the opposite charge, thus affecting chemotaxis. A set of experiments was designed to test this hypothesis.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2020

Author dc:creator

• Zhang, Yishu

Contributors dc:contributor

• Murphy, Catherine Jones

• Gold nanoparticles
• chemotaxis
• cell migration

Statement dc:rights

• Copyright 2020 Yishu Zhang

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/108525

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/108525