<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A synthetic peptide used to formulate and deliver deoxyribonucleic acids (DNA, usually in plasmid form) in gene therapy. The carrier peptides may condense plasmids into nano-particles with a hydrodynamic diameter ranging from 40 to 200 nm, which are sterically stable for long periods of time. Peptide-based gene delivery systems are used for transfection in a variety of cell lines. (NCI04)</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>