ASX/MEDIA RELEASE  31 July 2006

pSivida secures additional US$6.5m funding 

Boston, MA. and Perth, Australia - Global bio-nanotech company pSivida Limited (ASX:PSD, NASDAQ:PSDV, Xetra:PSI) is pleased to announce that it has signed an agreement with the Absolute Europe Catalyst Fund, Absolute Octane Fund and Australian IT Investments Ltd, subject to satisfaction of closing conditions, to purchase US$6.5m (AU$8.5m) of Subordinated Convertible Debentures convertible into pSivida American Depository Shares (ADSs) at an initial conversion price of US$2.00 per ADS (AU$0.27 per ordinary share).

The debentures will mature three years from the date of closing and will bear 8% interest payable quarterly in arrears and/or ADSs at an 8% discount to 10-day VWAP (Volume Weighted Average Price). The Company shall issue to the Investors warrant exercisable for a number of ADSs equal to 90% of the aggregate principal amount of the outstanding New Notes divided by the Conversion Price with an exercise price of US$2.00 and a term of 5 years. The Company may redeem the Notes at any time by payment of 108% of the face value and may force conversion when the ADR price remains above US$4.00 for a set period of 25 days.

ADSs issued upon conversion of the debentures or exercise of the warrants will be registered under the Securities Act of 1933 to permit resale in the United States within 180 days from the date of the agreement. The issue of shares underlying the ADSs and Warrants are subject to receipt of shareholder approval for the issuance at a Shareholders Extraordinary Meeting to be called in August and held in early September. The closing is anticipated to occur by September 15, 2006.

The US financing market for Biotech Companies has recently seen growing use of Convertible Note transactions. Mercury Investments Limited arranged the financing.

This announcement does not constitute an offer of any securities for sale or the solicitation of an offer to buy any securities. The securities offered will not be or have not been registered under the U.S. Securities Act of 1933, as amended, and may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements.

-ENDS-

pSivida Limited Brian Leedman Investor Relations pSivida Limited Tel: + 61 8 9226 5099 brianl@psivida.com US Public Relations Beverly Jedynak President Martin E. Janis & Company, Inc Tel: +1 (312) 943 1100 ext. 12 bjedynak@janispr.com European Public Relations Eva Reuter Tel: +49 (254) 393 0740 e.reuter@e-reuter-ir.com

NOTES TO EDITORS:

pSivida is a global bio-nanotech company committed to the biomedical sector and the development of drug delivery products. Retisert™ is FDA approved for the treatment of uveitis. Vitrasert® is FDA approved for the treatment of AIDS-related CMV Retinitis. Bausch & Lomb own the trademarks Vitrasert® and Retisert™. pSivida has licensed the technologies underlying both of these products to Bausch & Lomb. The technology underlying Medidur™, a treatment for diabetic macular edema, is licensed to Alimera Sciences and is in Phase III clinical trials.

pSivida owns the rights to develop and commercialise a modified form of silicon (porosified or nano-structured silicon) known as BioSilicon™, which has applications in drug delivery, wound healing, orthopaedics, and tissue engineering. pSivida’s subsidiary, AION Diagnostics Limited is developing diagnostic products and the subsidiary pSiNutria is developing food technology products both using BioSilicon™.

pSivida’s intellectual property portfolio consists of 70 patent families, 74 granted patents and over 290 patent applications. pSivida conducts its operations from offices and facilities near Boston in the United States, Malvern in the United Kingdom, Perth in Australia and Singapore.

pSivida is listed on NASDAQ (PSDV), the Australian Stock Exchange (PSD) and on the Frankfurt Stock Exchange on the XETRA system (German Symbol: PSI. Securities Code (WKN) 358705). pSivida is a founding member of the NASDAQ Health Care Index and the Merrill Lynch Nanotechnology Index.

The Company's largest shareholder and a strategic partner is QinetiQ, a leading international defence, security and Technology Company, formed in 2001 from the UK Government's Defence Evaluation & Research Agency (DERA). QinetiQ (QQ.) was instrumental in discovering BioSilicon^TM and pSivida’s strong relationship with QinetiQ includes access to its cutting edge research and development facilities.

For more information, visit www.psivida.com

This document contains forward-looking statements that involve risks and uncertainties. The statements reference potential products, applications and regulatory approvals. Although we believe that the expectations reflected in such forward-looking statements are reasonable at this time, we can give no assurance that such expectations will prove to be correct. Given these uncertainties, readers are cautioned not to place undue reliance on such forward-looking statements. Actual results could differ materially from those anticipated in these forward-looking statements due to many important factors including: our inability to develop proposed products, including without limitation, in the drug delivery, wound healing, orthopaedics, and tissue engineering, diagnostics and food technology fields; failure of our evaluation agreements to result in license agreements; failure to develop applications for BioSilicon™ due to regulatory, scientific or other issues; failure to complete negotiations for new centers for the BrachySil™ phase IIb clinical trial for inoperable primary liver cancer; failure of our discussions with the FDA for BrachySil™ to continue or to lead to FDA approval; failure of the BrachySil™ phase IIb clinical trial for inoperable primary liver cancer to determine the optimal dose, provide key safety data or support future pivotal efficacy trials or product registration or approval; failure of the BrachySil™ primary liver programme that is in phase IIb clinical trials to provide a valuable platform for the development and commercialisation of BrachySil™ for pancreatic cancer and other indications; failure to commence phase IIa BrachySil^TM trials for the treatment of pancreatic cancer; failure of the findings of the pancreatic cancer phase IIa trial to provide a platform for further multicentre efficacy and safety trials; failure of there to be optimisation and standardisation between our two  pancreatic cancer study centres; failure of the results of the Retisert™ for DME trial to be a good indicator of the results of pSivida’s ongoing phase III Medidur™ for DME trial; failure of the Medidur™ trials in DME to show a very similar improvement in visual acuity and diabetic retinopathy severity score as Retisert™ for DME; failure of Medidur™ to release fluocinolone acetonide at the same rate as Retisert™; our inability to recruit patients for the phase III Medidur™ for DME trial;. Other reasons are contained in cautionary statements in the Annual Report on Form 20-F filed with the U.S. Securities and Exchange Commission, including, without limitation, under Item 3.D, "Risk Factors" therein. We do not undertake to update any oral or written forward-looking statements that may be made by or on behalf of pSivida.