Oxygen is an essential nutrient for life. Yet, excessive combinations of certain forms of reactive oxygen species—known as free oxygen radicals—can result in cell mutations and cell death. Indeed, many diseases have been linked to free oxygen radials, including adult respiratory distress syndrome, heart attack, stroke, Parkinson’s disease, and complications associated with organ transplantation. Additionally, it has been shown that the harmful effects of exposure to toxic chemicals and radiation are directly related to generation of free oxygen radicals.

Tego Biosciences has developed a patented technology platform to treat such diseases. The platform is based on fullerenes, soccer-ball shaped molecules comprised of sixty carbon atoms. Because fullerenes have an external electron cloud, they can pick up electrons and eliminate dangerous free radicals. Indeed, they have been described as the most powerful anti-oxidant known. By themselves, however, fullerenes cannot be used for therapeutic purposes. Tego uses its proprietary technology to attach groups to the surface of fullerenes to make them more soluble and capable of reaching specific tissues in the body. If targeted to the right sites, fullerenes can stop the production of free radicals at their source. Since one free radical can damage hundreds or thousands of molecules, it is more effective to eliminate the free radical at the site it is produced rather at one of the thousands of sites it is damaging downstream.

Oxygen is an essential nutrient for life. Yet, excessive combinations of certain forms of reactive oxygen species—known as free oxygen radicals—can result in cell mutations and cell death. Indeed, many diseases have been linked to free oxygen radicals, including adult respiratory distress syndrome, heart attack, stroke, Parkinson’s disease, and complications associated with organ transplantation. Additionally, it has been shown that the harmful effects of exposure to toxic chemicals and radiation are directly related to generation of free oxygen radicals.

Substantial efforts have been devoted to developing antioxidants that can remove free radicals. Despite some success, there are no commercial products that are highly effective, non-toxic, inexpensive to manufacture, and can be tuned to possess other desirable properties such as the ability to cross the blood-brain barrier.

Tego Biosciences has developed a new class of therapeutics to treat oxidative injury. Tego’s strategy is to initially commercialize products that require the least capital and regulatory scrutiny. The company is initially focused on commercializing anti-wrinkle skin creams and cosmetics. Tego is also developing products to reduce the side effects of radiation therapy and chemotherapy and mitigate complications associated with organ transplantation and tissue engineering. In the long run, Tego intends to extend its platform to other, more complicated diseases such as neurological disorders.

Arrowhead Research Corporation 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 its majority-owned subsidiaries founded on nanotechnologies originally developed at universities. The company works closely with universities to source early-stage deals and to generate intellectual property covering promising new nanotechnologies. At present, Arrowhead has four other subsidiaries commercializing nanotechnology products and applications: Insert Therapeutics (drug delivery of anti-cancer therapeutics), Calando Pharmaceuticals (drug delivery of RNAi therapeutics), Unidym (carbon-based electronics) and Aonex Technologies (compound semiconductor materials).

Russ Lebovitz, Acting Chief Executive Officer
Russ worked for 15 + years as a successful senior scientist and research physician in a variety of academic settings before transitioning to a second career focused on financial, operational and executive management of emerging technology companies. In 1995 and 1996 Russ studied management and finance at Rice and Stanford Universities and subsequently worked for a variety of early and intermediate-stage biotech and medical device companies throughout the US . Between 1997 to 2003, Russ managed global projects in operations, marketing and finance for a number of Fortune 100 technology companies including Royal Dutch Shell, Nextel, Cingular Wireless, Johnson & Johnson, Compaq Computer and JPMorganChase, as well as with leading venture capital and investment banking firms. Russ has developed financial models and marketing plans that helped to raise over $100 million for early and intermediate stage pharmaceutical and biomedical device companies. Russ completed undergraduate studies at University of Michigan (Phi Beta Kappa), received his M.D. and Ph.D. degrees from Washington University in St. Louis and completed post-graduate biomedical training at the University of Pennsylvania, University of Toronto, Baylor College of Medicine and Washington University. Russ also served on the faculty of Baylor College of Medicine in Houston and The Fox Chase Cancer Center in Philadelphia.

Andreas Hirsch, Chief Science Officer
Andreas Hirsch is a Professor of Organic Chemistry at Friedrich-Alexander-Universität Erlangen-Nürnberg. He obtained his PhD at the University of Tuebingen, Germany and carried out postdoctoral research at the Institute of Polymers and Organic Solids in Santa Barbara, California, with Fred Wudl. He has received the Otto Roehm Preis (1994), the ADUC Jahrespreis für Habilitanden 1994 and the Elhuyar-Goldschmidt Prize 2006. Dr. Hirsch’s main research activities have been focused on the development of methodologies for efficient syntheses of exohedral derivatives of fullerenes and the use of such compounds as structural templates and building blocks for supramolecular architectures and nanomaterials. Other research interests are in the area of dendrimers, calixarene conjugates, new alkynes, new types of synthetic lipids and amphiphiles, model compounds for photoinduced charge transfer, chemical derivatization and solubilization of carbon nanotubes, including the investigation of their synthetic potential and properties as new materials. The group of Prof. Hirsch consists of about 20 doctoral students, diploma students and post docs. Andreas Hirsch is author of more than 150 publications.

Virginia Dadey, V.P. Business Development
Also the Vice President of Investor Relations at Arrowhead Research, Tego’s parent company, Ms. Dadey has 15 years of experience in financial markets as an investment specialist. Ms. Dadey has developed intimate knowledge of a wide array of nanotech and biotech companies, including emerging players. She brings to Tego a successful track record in nanotech deal-making and a wide network of contacts, including domestic and international analysts and fund managers. Prior to Arrowhead, Dadey worked for the Maxim Group and its predecessor company, Investec, since 2001. She was a vice president at Gruntal & Co. from 1996 to 2001. She received her B.S. in Nutritional Science from Purdue University.

MyPhuong Lam, VP of Finance
MyPhuong received her MBA from Rice University in 2003, with a concentration in finance. Since graduating from the Rice MBA program in 2003, MyPhuong has served as the Director of Finance for
C Sixty Inc., a Houston pharmaceutical start-up from 2003-2006. In 2006 and 2007, MyPhuong worked with Deloitte Financial Advisory Services peforming business valuation for both pre- and post transaction deals across a variety of industries. Prior to business school, she also served as part of the Research Mission Management team on international scientific projects for the NASA/Mir and the International Space Station programs in which she worked extensively in both the US and Russia.

Andrew Barron, PhD
Professor Barron is the Charles W. Duncan, Jr. – Welch Chair of Chemistry, a Professor of Materials Science, and the Associate Dean for Industry Interactions and Technology Transfer at Rice University. Research in the Barron Group at the Rice University is currently aimed at the development of rational molecular design approach to materials synthesis, with an emphasis on the leap from synthesis to application of nano-based materials.

Dennis Choi, MD PhD
Dr. Choi is currently Executive Director of Emory¹s university-wide neurosciences initiative. He also directs the Comprehensive Neurosciences Center within Emory’s Woodruff Health Sciences Center, responsible for integrating patient care, research, and education. Prior to joining Emory, Dr. Choi served as Executive Vice-President for Neuroscience at Merck Research Labs from 2001 to 2006. Between 1991 and 2001, Dr. Choi served as head of the Neurology Department at Washington University Medical School; there he established the Center for the Study of Nervous System Injury, and directed the McDonnell Center for Cellular and Molecular Neurobiology.

Derivatized fullerenes can be used in a wide range of applications outside of Tego’s development efforts such as MRI imaging and osteoporosis therapy. Tego’s patent portfolio covers derivatized fullerene compositions of matter, methods of making, and a range of different applications. Tego is seeking partners who are interested in licensing intellectual property and commercializing products outside the scope of Tego’s development efforts.

Arrowhead’s New BioScience Subsidiary Plans Preclinical Studies and Collaboration With NCI

PASADENA, Calif.—June 25, 2007—Arrowhead Research Corporation (NASDAQ: ARWR), announced today that its new wholly-owned nanobioscience subsidiary has changed its name from “C Sixty Acquisition Corp”. to “Tego BioSciences Corporation”. The subsidiary recently acquired the assets of C Sixty, Inc. and is focused on the development of new protective products based on the anti-oxidant properties of modified buckministerfullerenes (also known as fullerenes or buckyballs). Tego is initially developing products to reduce oxidative damage caused by sun exposure, radiation therapy, and chemotherapy and mitigate complications associated with organ transplantation and tissue engineering.

“Tego is set to commence preclinical animal studies in collaboration with the National Cancer Institute this summer,” said R. Bruce Stewart, Chairman of Arrowhead. “Tego is in the process of assembling a business and technical team with expertise in nanoparticle-based therapeutics and skin care products.”

The preclinical studies will be performed in the NCI’s Nanotechnology Characterization Lab (NCL) to measure the ability of a Tego fullerene formulation to protect against harmful side effects of two anti-cancer drugs, cisplastin and adriamycin. The first stage of the studies will use NCL’s resources, with follow on funding from Tego, as appropriate.

The National Cancer Institute (NCI), working in concert with the National Institute of Standards and Technology (NIST) and the U.S. Food and Drug Administration (FDA), established the Nanotechnology Characterization Laboratory (ncl.cancer.gov) to perform preclinical efficacy and toxicity testing of nanoparticles. The NCL serves as a national resource and knowledge base for all cancer researchers to facilitate the regulatory review of nanotechnologies intended for cancer therapies and diagnostics. By providing the critical infrastructure and characterization services to nanomaterial providers, the NCL can accelerate the transition of basic nanoscale particles and devices into clinical applications, thereby reducing suffering and death from cancer.

About Arrowhead Research Corporation
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 five subsidiaries commercializing nanotech products and applications, including anti-cancer drugs, RNAi therapeutics, carbon-based electronics and compound semiconductor materials.

About Tego BioSciences Corporation
Tego BioSciences Corporation (www.tegobio.com) is developing and commercializing therapeutics and other products based on the antioxidant properties of modified fullerenes. The patent protected platform forms the basis for several products. The company is initially focused on developing products to reduce oxidative damage caused by sun exposure, radiation therapy, and chemotherapy and mitigate complications associated with organ transplantation and tissue engineering. For other applications of derivatized fullerenes such as MRI imaging or central nervous system disorders, Tego BioSciences will establish a program to license and partner the commercialization of its intellectual property to third parties.

Fullerenes are a highly structured, nanoscale form of carbon, similar to carbon nanotubes.  Roughly one nanometer in diameter, the molecules are composed of 60 carbon atoms and have the symmetry of soccer balls. The spherical shape, hollow interior, and 60 carbon atoms of the molecule allow drug designers the opportunity to attach therapeutic and targeting chemical groups in many configurations.

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. 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 Statements 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.

Virginia E. Dadey
Arrowhead Research Corporation
212-541-3707
vdadey@arrowres.com