The compositions, systems, and methods relate to substituted and asymmetric gemini surfactants for use in delivering biologically active agents, such as nucleic acids, to a subject. The described compositions, systems, and methods are useful for gene therapy.
 Funding was provided by the Natural Sciences and Engineering Research Council of Canada (NSERC), the Canadian Institutes of Health research (CIHR), and a fellowship from the Saskatchewan Synchrotron Institute. Use of the National Synchrotron Light Source, Brookhaven National Laboratory, was supported by the U.S. Department of Energy under Contract No. DE-AC02-98CH10886. Accordingly, the Canadian and/or United States government(s) may retain certain rights in the present invention.