Press Room

ARROWHEAD SUBSIDIARY SIGNS AGREEMENT TO INTEGRATE ITS PRODUCTS INTO MAJOR DISPLAY MANUFACTURER'S FLAT PANEL DISPLAYS

Pasadena, CA, July 30, 2007

Arrowhead Research (NASDAQ: ARWR) announced today that its majority owned subsidiary, Unidym, has entered an agreement with a major liquid crystal display (LCD) manufacturer to integrate carbon nanotube-based products into display applications.

"The market for flat panel displays is over eighty billion dollars annually, and we are now working with one of the world's leaders," remarked Art Swift, CEO of Unidym. "We expect our products to reduce manufacturing costs and improve image quality in flat panel displays."

Under the terms of the agreement, Unidym will work with the customer to integrate its products into the customer's manufacturing process. Upon conclusion of the development effort, the parties intend to enter a commercial relationship.

About Arrowhead Research Corp.
Arrowhead Research Corporation (www.arrowheadresearch.com) is a publicly-traded nanotechnology company commercializing new technologies in the areas of life sciences, electronics, and energy. Arrowhead is building value for shareholders through the progress of majority owned subsidiaries founded on nanotechnologies originally developed at universities. The company works closely with universities to source early stage deals and to generate rights to intellectual property covering promising new nanotechnologies. Currently, Arrowhead has four subsidiaries commercializing nanotech products and applications, including anti-cancer drugs, RNAi therapeutics, carbon-based electronics and compound semiconductor materials.

About Unidym, Inc.
Unidym, Inc. is developing low-cost, carbon-based materials, processes, and devices for the electronics industry. The Company's initial product is a thin, transparent film of carbon nanotubes that replaces the expensive, failure-prone materials currently employed by manufacturers of devices such as touch screens, flat panel displays, and solid state lighting. Unidym is also developing novel carbon nanotube-based transistors and conductive inks for the printable electronics industry to replace today¡¦s complex and capital intensive semiconductor manufacturing processes with inexpensive, solution-based printing processes. Unidym differentiates itself through its emphasis on low-cost materials and processes, in-house carbon nanotube production, aggressive partnership strategy, and significant intellectual property portfolio that includes foundational IP in both of its initial applications.

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 factorsand uncertainties, including the recent economic slowdown affecting technology companies, 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 filingsdiscuss 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.