Marina Biotech, Inc., a leading RNAi-based drug discovery and development company, today announced that the U.S. Patent and Trademark Office has issued a Notice of Allowance for patent application U.S. 11/745,003 broadly covering amphoteric liposomal formulations, including the Company's proprietary SMARTICLES(R) technology, for delivery of siRNAs and other compounds with therapeutic application.

"Delivery of nucleic acids remains the biggest hurdle to successful development of RNAi-based therapeutics," said Barry Polisky, Ph.D., Chief Scientific Officer of Marina Biotech. "Amphoteric liposomes enable the precise control of the charge and fusion properties of a liposome which are key requisites for effective delivery, and do not require additional surface modification to stabilize and mask the particle from undesirable biological interactions. These unique characteristics differentiate amphoteric liposomes from standard liposomes used by others in the RNAi field, and provide a broad platform for the efficient delivery of RNAi-based therapeutics."

"We believe this patent allowance represents the fundamental IP necessary for developing amphoteric liposomal delivery systems for RNAi-based therapeutics," stated J. Michael French, President and CEO at Marina Biotech. "This allowance significantly enhances the company's IP position, and firmly establishes our competitive advantage with respect to RNAi-based delivery systems. In the near future, we expect to see additional patent allowances for Marina Biotech related to our fundamental IP covering the DiLA2 delivery platform, tkRNAi platform (bacterial delivery platform) and our peptide nanoparticle delivery platform."