Compositions for expressing a polypeptide within a target organ, the composition comprising a delivery particle, and at least a first mRNA sequence complexed with, encapsulated by, or otherwise associated with the delivery particle, wherein the mRNA sequence comprises at least one coding sequence which codes for at least one polypeptide, at least a first untranslated region (UTR) sequence, and at least one micro-RNA (miRNA) binding site sequence, wherein the miRNA binding site sequence is located within, immediately 5′ to, or immediately 3′ to, the first UTR sequence; and wherein the miRNA binding site sequence provides for differential expression of the coding sequence between first and second cell types comprised within the target organ.