Marina Biotech, Inc.

Novosom Verwaltungs Gmbh

Claudia Müller

Steffen Panzner

Silke Lutz

Evgenios Siepi

Christian Reinsch

Ute Vinzens

An amphoteric liposome composed of a mixture of lipids, said mixture comprising a cationic amphiphile, an anionic amphiphile and optionally one or more neutral amphiphiles, at least one of said cationic and anionic amphiphiles being chargeable and the respective amounts of said cationic and anionic amphiphiles being selected such there is a stoichiometric excess of positively charged cationic amphiphile at a first lower pH, a stoichiometric excess of negatively charged anionic amphiphile at a second higher pH and said mixture has an isoelectric point intermediate said first and second pHs; characterised in that said positively charged cationic and negatively charged anionic amphiphiles are adapted to form a lipid salt with one another at said isoelectric point. Also disclosed are methods of predicting the fusogenicity of an amphoteric liposome at a given pH, formulating an amphoteric liposome and loading an amphoteric liposome with a cargo moiety.

Amphoteric liposomes, a method of formulating an amphoteric liposome and a method of loading an amphoteric liposome

Lipid assemblies, such as liposomes, comprising transfection enhancer elements (TEE's), which are complexed with the lipid assemblies by means of ionic interactions, or lipids incorporating such TEE's are disclosed for enhancing the fusogenicity of the lipid assemblies. The TEE's have the formula:hydrophobic moiety-pH sensitive hydrophilic moiety&#x2003;&#x2003;(II)The pH sensitive hydrophilic moiety of each TEE is a weak acid having a pka of between 2 and 6 or a zwitterionic structure comprising a combination of acidic groups with weak bases having a pKa of between 3 and 8. Lipids incorporating one or more such TEEs have the formula (I):Lipid moiety-[Hydrophobic moiety-pH sensitive hydrophilic moiety]&#x2003;&#x2003;(I).

Lipids and lipid assemblies comprising transfection enhancer elements

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Munich, Georgia

Claudia Müller