Psivida earns new European patent

Perth-based biotech-nanotech company pSivida (ASX:PSD) announced today that its UK subsidiary PsiMedica has been granted the latest in a series of European patents on its proprietary biocompatible-biodegradable silicon technology, BioSilicon.

European Patent 1 175 233 B1 relates to the use of Psivida's nanoporous silicon -- a biocompatible, biodegradable form of silicon honeycombed with ultra-microscopic holes -- as a substrate for a range of surface-bound chemical molecules, including proteins.

According to the company, the patent describes a suite of techniques for attaching chemical molecules, including large protein molecules, to BioSilicon chips. The processes induce tight binding between the molecules and 'derivatised' BioSilicon chips, in such a way that the molecules function as ligands for complementary molecules.

The range of molecules that can be attached to Psivida's BioSilicon chips includes large proteins like monoclonal antibodies, which the company says can be used as diagnostics for infectious and non-infectious diseases, or as prognostics to monitor fluctuating levels of hormones and other biochemical compounds that may indicate disease states such as relapse in cancer patients.

The surface of the chips can be customised -- or 'derivatised', as pSivida describes the synthesis procedure -- to produce a charge that induces the selected ligand type to bind tightly to the nanoporous silicon surface.

Psivida MD Gavin Rezos said the new European patent further added to the company's already strong IP portfolio, in the wake of its recent US patent grant for potential 'smart' drug delivery systems based on BioSilicon, one of six previous patent grants in the UK and US.

Rezos said pSiMedica's IP portfolio now consisted of 17 patent families, with nine patents already granted, and more than 70 patent applications still pending. They cover bioactive, resorbable and biocompatible forms of silicon for intelligent drug delivery devices, orthopaedic implants and intelligent diagnostic tools.