U.S. Patent and Trademark Office Issues Fundamental Patent for Carbon Nanotube-Based Transparent Electrodes

Business Wire, Sept 12, 2007

MENLO PARK, Calif. -- Unidym, Inc., a majority-owned subsidiary of Arrowhead Research Corporation (NASDAQ:ARWR), announced today that U.S. Patent No. 7,265,174 has been issued by the U.S. Patent and Trademark Office. With respect to transparent conductive films, Clemson University has exclusively licensed this patent to Unidym. Unidym is a leader in the development and manufacture of carbon nanotubes for applications in the electronics industry. Unidym, which recently merged with Carbon Nanotechnologies, Inc. (CNI), possesses a foundational patent portfolio that covers nearly every aspect of carbon nanotube manufacturing and processing.

U.S. Patent No. 7,265,174 includes composition of matter claims covering nanotube-based films that are electrically conductive and at least 80% optically transparent. It is the latest addition to Unidym's extensive patent portfolio on carbon nanotechnology, now numbering over 70 issued U.S. Patents.

"The issued patent covers products that Unidym is currently developing for the touch screen, flat panel display, solar cell and solid state lighting markets," stated Art Swift, President and CEO of Unidym. "With its March 22, 2001 priority date, this patent predates any similar composition of matter claim that we know of."

In addition to this patent, Unidym owns or has exclusive rights to a growing number of issued patents covering fundamental compositions of matter, manufacturing of carbon nanotubes, and processing of carbon nanotubes (purification, dispersion, functionalization, and doping). Unidym also owns or has exclusive rights to issued patents and patent applications covering other nanotube-based products such as composites, therapeutics, solar cells, and transistors.

About Unidym, Inc.

Unidym (www.unidym.com) is a leader in the manufacture and application of carbon nanotubes (CNTs), a novel material with extraordinary electrical, thermal, and mechanical properties. Unidym provides bulk materials, CNT-enabled products, and intellectual property to a wide range of customers and business partners. As a result of its recent merger with CNI, Unidym possesses a foundational patent portfolio that covers nearly every aspect of CNT manufacturing and processing as well as multiple product applications.

Unidym is focused on the electronics industry where its initial products include transparent electrodes for touch screens, flat panel displays, solar cells, and solid state lighting; electrodes for fuel cells; and thin film transistors for printable electronics. Unidym is also pursuing a cross-industry partnership strategy to capture value from the wide ranging uses of CNTs. Unidym's licensing program, technical expertise and manufacturing facilities can enable partners to rapidly develop CNT solutions for their specific applications.

Unidym is a majority-owned subsidiary of Arrowhead Research Corporation (NASDAQ: ARWR) For more information about Arrowhead, please visit www.arrowheadresearch.com.

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 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. Arrowhead's 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 Statements on Form S-3, and other SEC filings discuss some of the important risk factors that may affect Unidym's business, results of operations and financial condition. We undertake no obligation to revise or update publicly any forward-looking statements for any reason.