Download Investigating the Biophysical Properties of Cytochrome c in

Investigating the Biophysical Properties of Cytochrome c in Hyaluronic Acid
Nanocarriers for Targeted Drug Delivery System Applications
Bethzaida N. Suárez1, Cindy M. Figueroa1 and Kai Griebenow1, Ph.D.
1Department
of Chemistry, University of Puerto Rico Rio Piedras, San Juan, P.R.
Currently, cancer is accountable for approximately 25% of all deaths in the United States.
Being one of the leading causes of mortality worldwide emphasizes the need for the
development of novel drug delivery systems that specifically target these rapidly proliferating
malignant cells without inducing toxicity in normal cells. Conventional chemotherapeutic
approaches for cancer have little or no specificity leading not only to systemic toxicity but also
to severe side effects. Targeted drug delivery systems have been studied extensively as they
reduce these particularly toxic side effects. Furthermore, tumor cells express an array of
receptors and molecular markers that can be used as targets for the delivery of cytotoxic drugs.
Cytochrome c (Cyt c) is a small heme protein, which induces apoptosis when released from the
mitochondria. Since it is impermeable to the cellular membrane, hyaluronic acid (HA) was
selected to deliver Cyt c into the intracellular space. HA has emerged as a promising drug
carrier as the HA receptor has been found to have elevated levels of expression in many tumors
as compared to its expression in normal cells. Most importantly, the active ligand HA can
provide protection and stability to Cyt c during the delivery process inside the cell. That is, HA
can function not only as a carrier but also as a stabilizer for the apoptotic protein, Cyt c. This
highlights one of the most significant challenges in the use of proteins for the development of
novel drugs, which is the instability issues that arise from their complex and colloidal nature
when faced to different chemical environments in the delivery process. Herein, the aim of this
project is to investigate the biophysical properties of Cyt c when assembled into Cyt c-HA
bioconjugates for its use in targeted cytotoxic drug delivery systems into the intracellular
space of cancer cells.