The present invention relates to a retro viral system for the transfer of non-viral RNA into target cells and more particularly a retroviral particle capable of delivering multiple RNAs. More particularly, it relates to retroviral particles comprising a protein derived from the Gag polyprotein, an envelope protein, optionally an integrase and at least two encapsidated non-viral RNAs, the encapsidated non-viral RNAs each comprising an RNA sequence of interest linked to an encapsidation sequence, each encapsidation sequence being recognised by a binding domain introduced into the protein derived from the Gag polyprotein and/or into the integrase.

The present invention relates to a retroviral system for the transfer of non-viral RNA into target cells and more particularly a retroviral particle capable of delivering multiple RNAs. More particularly, it relates to retroviral particles comprising a protein derived from the Gag polyprotein an envelope protein, optionally an integrase and at least two encapsidated non-viral RNAs, the encapsidated non-viral RNAs each comprising an RNA sequence of interest linked to an encapsidation sequence, each encapsidation sequence being recognised by a binding domain introduced into the protein derived from the Gag polyprotein and/or into the integrase.

The present invention relates to a retroviral system for the transfer of non-viral RNA into target cells and more particularly a retroviral particle capable of delivering multiple RNAs. More particularly, it relates to retroviral particles comprising a protein derived from the Gag polyprotein an envelope protein, optionally an integrase and at least two encapsidated non-viral RNAs, the encapsidated non-viral RNAs each comprising an RNA sequence of interest linked to an encapsidation sequence, each encapsidation sequence being recognised by a binding domain introduced into the protein derived from the Gag polyprotein and/or into the integrase.

A combined packing and assembly method that efficiently packs ribonucleic acid (RNA) into virus like particles (VLPs) has been developed. The VLPs can spontaneously assemble and load RNA in vivo, efficiently packaging specifically designed RNAs at high densities and with high purity. In some embodiments the RNA is capable of interference activity, or is a precursor of a RNA capable of causing interference activity. Compositions and methods for the efficient expression, production and purification of VLP-RNAs are provided. VLP-RNAs can be used for the storage of RNA for long periods, and provide the ability to deliver RNA in stable form that is readily taken up by cells.