Arrowhead Scientific Advisory Board Member Appointed to the President's Council of Advisors on Science and Technology

PASADENA, Calif.--(Business Wire)--
Arrowhead Research Corporation (Nasdaq: ARWR) today announced that the Company`s
Scientific Advisory Board member Dr. Chad Mirkin has been appointed to the
President's Council of Advisors on Science and Technology (PCAST). PCAST is part
of the Executive Office of the President and is administered by the Office of
Science and Technology Policy.

PCAST was established in 1990 to enable the President of the United States to
receive advice from the private sector and academic community on issues related
to technology, scientific research priorities and math and science education.
President Obama announced the new membership of PCAST on April 27, 2009, which
includes 20 of the nation`s leading scientists and engineers.

Dr. Christopher Anzalone, Arrowhead`s President and CEO, stated, "We
congratulate Dr. Mirkin on this distinguished honor which recognizes a career of
outstanding accomplishments both as a leading nanotechnology researcher and
successful entrepreneur in the field. Dr. Mirkin has been a valuable advisor to
Arrowhead, and we view this appointment as an endorsement of his key role in
making nanotechnology a driving force for innovation. We wish him the very best
as he contributes his extraordinary knowledge and perspectives to President
Obama`s Council of Advisors on Science and Technology."

More information about PCAST is available at http://www.ostp.gov/cs/pcast.

Dr. Chad Mirkin - Biography

Dr. Chad Mirkin has been recognized for his accomplishments with over 50
national and international Awards. These include a iCON Innovator of the Year
Award (2007), NIH Director`s Pioneer Award, the Collegiate Inventors Award
(2002, 2004), an Honorary Doctorate Degree from Dickinson College, the
Pennsylvania State University Outstanding Science Alumni Award, the ACS Nobel
Laureate Signature Award for Graduate Education in Chemistry, a Dickinson
College Metzger-Conway Fellowship, the 2003 Raymond and Beverly Sackler Prize in
the Physical Sciences, the Feynman Prize in Nanotechnology, the Leo Hendrick
Baekeland Award, Crain`s Chicago Business "40 under 40 Award," the Discover 2000
Award for Technological Innovation, I-Street Magazine`s Top 5 List for Leading
Academics in Technology, the Materials Research Society Young Investigator
Award, the ACS Award in Pure Chemistry, the PLU Fresenius Award, the Harvard
University E. Bright Wilson Prize, the BF Goodrich Collegiate Inventors Award,
the Camille Dreyfus Teacher-Scholar Award, the Alfred P. Sloan Foundation Award,
the DuPont Young Professor Award, the NSF Young Investigator Award, the Naval
Young Investigator Award, the Beckman Young Investigator Award, and the Dreyfus
Foundation New Faculty Award. He is a Fellow of the American Association for the
Advancement of Science and has served on the Editorial Advisory Boards of over
twenty scholarly journals. At present he is a member of the Editorial Advisory
Boards of Accounts of Chemical Research, Advanced Materials, Angewandte Chemie,
BioMacromolecules, Macromolecular Bioscience, SENSORS, Encyclopedia of
Nanoscience and Nanotechnology, Chemistry-A European Journal, Chemistry &
Biology, Nanotechnology Law & Business, The Scientist, Journal of Materials
Chemistry, and Journal of Cluster Science, Plasmonics. Dr. Mirkin is the
founding editor of the journal Small, one of the premier international
nanotechnology journals, and he has co-edited two bestselling books on the field
of nanobiotechnology.

Dr. Mirkin holds a B.S. degree from Dickinson College (1986, elected into Phi
Beta Kappa) and a Ph.D. degree in chemistry from the Pennsylvania State
University (1989). He was an NSF Postdoctoral Fellow at the Massachusetts
Institute of Technology prior to becoming a chemistry professor at Northwestern
University in 1991.

About Arrowhead Research Corporation

Arrowhead Research Corporation (www.arrowheadresearch.com) (NASDAQ: ARWR) is a
nanotechnology company commercializing new technologies in the areas of life
sciences, electronics, and energy. Arrowhead is seeking to build value for
shareholders through the progress of majority owned subsidiaries. Currently,
Arrowhead has four subsidiaries commercializing nanotech products and
applications and minority investments in two privately held nanobiotech
companies.

Safe Harbor Statement under the Private Securities Litigation Reform Act of
1995:

This news release contains forward-looking statements within the meaning of the
"safe harbor" provisions of the Private Securities Litigation Reform Act of
1995. These statements are based upon our current expectations and speak only as
of the date hereof. Our actual results may differ materially and adversely from
those expressed in any forward-looking statements as a result of various factors
and uncertainties, including the recent economic slowdown, capital resources
available to us, the future success of our scientific studies, our ability to
successfully develop products, rapid technological change in our markets,
changes in demand for our future products, legislative, regulatory and
competitive developments and general economic conditions. Our Annual Report on
Form 10-K and 10-K/A, recent and forthcoming Quarterly Reports on Form 10-Q and
10-Q/A, recent Current Reports on Forms 8-K and 8-K/A, our Registration
Statement on Form S-3, and other SEC filings discuss some of the important risk
factors that may affect our business, results of operations and financial
condition. We undertake no obligation to revise or update publicly any
forward-looking statements for any reason.

Investor Contact:
The Piacente Group
Sanjay M. Hurry, 212-481-2050
sanjay@tpg-ir.com

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