DOI

10.17077/etd.kopomg6p

Document Type

Thesis

Date of Degree

Spring 2017

Access Restrictions

.

Degree Name

MS (Master of Science)

Degree In

Chemical and Biochemical Engineering

First Advisor

Grassian, Vicki H

Second Advisor

Fiegel, Jennifer

First Committee Member

Grassian, Vicki H

Second Committee Member

Fiegel, Jennifer

Third Committee Member

Salem, Aliasger K

Abstract

Nanoparticles are currently used in a wide range of applications including industrially processes, consumer products, and as drug delivery vehicles. The potential toxicity of these nanoparticles in living organisms is concerning due to their ever-expanding applications and accumulation in the environment. The effects of properties of the human body on the potential harmful nature of these nanoparticles must be understood in order to ensure safety in workplaces and at-home products.

In this thesis, the interactions between nanoparticles and the most abundant blood protein, serum albumin, were investigated. The effects of changing the aqueous environment was investigated over a range of different pH values and with different ionic salts dissolved in water. The effects of changing the nanoparticle substrate were investigated to determine if different nanoparticles affect proteins differently. Finally, the effects of changing the concentration of nanoparticles and the presence of protein were investigated in a model lung cell line in vitro.

The studies over different pH values revealed that serum albumin was able to adsorb to the silica nanoparticle surface, and retained its secondary structure both as a function of pH and adsorption in a 2-hour time frame. However, adsorption was greater on the titanium dioxide nanoparticle surface and the protein lost secondary structure at acidic pH (pH 2.0). Studies with different ionic salts revealed a possible correlation between BSA adsorption and nanoparticle aggregation in that the attractive interactions between nanoparticles were least when the least amount of protein was adsorbed. To the nanoparticle surface. In vitro studies with A549 human adenocarcinoma lung cells were inconclusive in determining the potential toxicity of these nanoparticles, but preliminary results suggested that the addition of protein to the system decreased toxicity compared with nanoparticles alone. This research aims to inform the field of nanotechnology to investigate the safety and efficacy of nanoparticles before they reach the consumer.

Public Abstract

The field of nanotechnology is rapidly growing and utilizes tiny particles for unique functions. The scientific advances in the field have led to an increase in nanoparticles used in common household products including: sunscreen, paints, and long-acting prescription drugs. However, harmful effects these nanoparticles may have on human health are widely unknown. The goal of this research is to investigate the properties of nanoparticles in the presence of the most-abundant blood protein to improve the understanding of nano-bio interactions. Studies were completed using a variety of aqueous solutions and comparing properties such as nanoparticle aggregation, protein adsorption to the nanoparticle surfaces, and the protein structure to determine whether these nanoparticles are harmful to biological components.

Silicon dioxide (silica) nanoparticles were chosen because they are used in all of the aforementioned products. The protein bovine serum albumin (BSA) was added to silica systems to investigate changes in the properties of the nanoparticles. Additionally, a model lung cell was used to determine the responses of the smallest living component to the human body. The results from this study suggest that silica nanoparticles are not harmful to human cells in low doses for short exposure times.

Keywords

bovine serum albumin, nano-bio interactions, nanoparticles

Pages

xiii, 77 pages

Bibliography

Includes bibliographical references (pages 68-77).

Copyright

Copyright © 2017 Brittany Estelle Givens

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