Abstract: Compositions and methods are provided for treating cancer by administering a complex formed between a therapeutic polynucleotide and a 3E10 antibody or variant thereof, or antigen-binding fragment thereof. In some instances, the complexes are stabilized through a molar ratio of 3E10 antibody or variant thereof, or antigen-binding fragment thereof to therapeutic polynucleotide of at least about 2:1.

Abstract: Compositions and methods are provided for treating myopathies by administering a complex formed between a therapeutic mRNA polynucleotide and a 3E10 antibody or variant thereof, or antigen-binding fragment thereof. In some instances, the complexes are stabilized through a molar ratio of 3E10 antibody or variant thereof, or antigen-binding fragment thereof to therapeutic polynucleotide of at least about 2:1.

Abstract: Compositions and methods are provided for delivering therapeutic polynucleotides by administering a complex formed between a therapeutic polynucleotide having a 3E10 or 3E10 variant binding domain and a 3E10 antibody or variant thereof, or antigen-binding fragment thereof. In some instances, the complexes are stabilized through a molar ratio of 3E10 antibody or variant thereof, or antigen-binding fragment thereof to therapeutic polynucleotide of at least about 2:1.

Abstract: Compositions and methods of use thereof for delivering nucleic acid cargo into cells are provided. The compositions typically include (a) a 3E10 monoclonal antibody or an antigen binding, cell-penetrating fragment thereof; a monovalent, divalent, or multivalent single chain variable fragment (scFv); or a diabody; or humanized form or variant thereof, and (b) a nucleic acid cargo including, for example, a nucleic acid encoding a polypeptide, a functional nucleic acid, a nucleic acid encoding a functional nucleic acid, or a combination thereof. Elements (a) and (b) are typically non-covalently linked to form a complex.