A major focus in gene therapy research for hemophilia is the development of new technologies
that mitigate the immune response, simultaneously delivering genes to target cells in order to
help host cells manufacture life-saving proteins, such as clotting factors. A team of researchers
from the Department of Bioengineering at the University of Washington recently reported the
development of a novel technology to transport drugs into hepatocytes, or liver cells, using gold
nanoparticles as the agents for delivery. The study, “Gold Nanoparticles as a Versatile Platform
for Optimizing Physiochemical Parameters for Targeted Drug Delivery,” was published in the
July 14, 2006 issue of Macromolecular Science. Although the focus of the study was broad – on
drug delivery, in general – it revealed a unique means of delivering gene therapy to treat
hemophilia that literally includes a little bit of gold.
Using the murine (mouse) model, Jamie M. Bergen, a graduate student in bioengineering at the
University of Washington in Seattle, and colleagues were able to learn a lot about how the body
responds to gold nanoparticles in-vivo, or inside the living body. Nanoparticles are no larger than
a billionth of a meter in size. After coating the pieces with gold, researchers began to experiment
with nanoparticles of varying size and different coatings. The researchers were able to identify
that the liver preferentially absorbs gold nanoparticles 50 nanometers in diameter coated with
pegylated-galactose* over gold nanoparticles of any other size.
Previous research showed that the liver is an apt target for gene therapy because hepatocytes can
express genes introduced into the genome via gene therapy at therapeutically significant levels,
for prolonged periods, while circumventing the body’s own immune response.
While many more experiments are necessary before research on gold nanoparticles are even
considered in humans, researchers at the University of Washington have presented a generative
scientific investigation that resonates with “It’s Time for a Cure,” a fundraising campaign first
launched in the 1990s by the National Hemophilia Foundation to foster research leading to a cure
for bleeding disorders.
Co-author Suzie H. Pun, PhD, is Assistant Professor of Bioengineering at the University of
Washington in Seattle. She received the National Hemophilia Foundation Career Development
Award in 2004.
* A polymer made of a simple sugar with polyethylene glycol, a therapeutic protein.
Source: Bergen J, von Recum H, Goodman T, et al. Gold nanoparticles as a versatile platform for
optimizing physiochemical parameters for targeted drug delivery. Macromolecular Science. July
14, 2006; 6: 506-516.