Campus Access Only

All rights reserved. This publication is intended for use solely by faculty, students, and staff of University of the Pacific. No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, now known or later developed, including but not limited to photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author or the publisher.

Date of Award

2012

Document Type

Thesis - Pacific Access Restricted

Degree Name

Master of Science (M.S.)

Department

Biological Sciences

First Advisor

Bhaskara Jasti

First Committee Member

Xiaoling Li

Second Committee Member

Lisa Wrischnik

Third Committee Member

Craig Vierra

Abstract

Current chemotherapeutics pose many di sadvantages due to their lack of specificity and low therapeutic index. To overcome these challenges, research has focused its attention on the development of nano-based delivery systems that can penetrate the leaky vasculature of tumor endothelium, use site-directed ligands that can bind with high affinity and specific ity to tumor cells, physically entrap poorly soluble drugs, and deliver these cytotoxic agents directly to the tumor site. One approach to nanosystem drug delivery is with the use of peptide amphiphiles (PAs) that are conjugated with the Arginine-Glycine-Aspartic Acid (RGD) motif to actively target a αVβ3 integrin receptors on cancer cells or tumor endothelium. The current work is focused on mechanistic studies to evaluate the uptake of novel RGD amphiphi les with varying alkyl chain lengths (palmitic acid : Cl 6 and stearic acid: C 18) and hydrophilic linkers, 8-amino- 3,6-dioxaoctonoic acid (ADA) or glucose, as micellar delivery systems of hydrophobic anticancer agents. PAs were confirmed for their self-assembling properties and further evaluated for their RGD-mediated binding specificity to purified αVβ3 integrin through a competitive binding fluorescence polarization assay (with novel RGD micelles displacing an integrin-bound fluorescent RGD probe by as much as 63.03%). Ultimately, these nanocarriers were assessed for their ability to deliver phys ically entrapped fluorescein isoth iocyanate (FITC) to A2058 cells overexpressing αVβ3 integrin receptors. Results from confocal microscopy indicate that uptake of RGD micelles was driven by an energy-dependent mechanism, as statistically significant levels of FITC internalization was seen at 37°C versus 4°C (p-value<0.05 for all treatment groups); moreover, intracellular fluorescence was notably higher (as much as 4-fold) when delivered through novel RGD conjugates as opposed to its free form. Regardless of chain length and the number of hydrophilic linkers, all RGD PAs showed promising results as micellar carriers that can effectively deliver their payload to the target tumor site via receptor mediated endocytosis.

Pages

86

To access this thesis/dissertation you must have a valid pacific.edu email address and log-in to Scholarly Commons.

Find in PacificSearch

Share

COinS

If you are the author and would like to grant permission to make your work openly accessible, please email

 

Rights Statement

Rights Statement

In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/
This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).