Abstract: A voltage-gated sodium channel expression system is described. The system comprises providing a polycistronic RNA message that encodes a polyprotein comprising a voltage-gated sodium channel alpha protein (Nav?) subunit and one or more voltage-gated sodium channel beta protein (Nav?) subunits, each of said subunits being separated by a 2A self-cleaving peptide. During translation, the polyprotein is cleaved into individual subunit proteins which can assemble into a voltage-gated sodium channel. Host cells and lipoparticles comprising the sodium channel expression system are also provided.

Abstract: Antibodies and antigen-binding fragments thereof that bind the human voltage-gated sodium channel Nav1.7? protein subunit (Nav1.7 binders) are described. In particular embodiments, the Nav1.7 binders comprise a heavy-chain immunoglobulin single variable domain (ISVD or VHH).