Abstract: Compositions for transporting a bioactive agent across a biological membrane include the bioactive agent, an oil, an oil-immiscible compound and a noncationic surface active agent. The compositions may deliver the bioactive agent through a chemical microporulation mechanism, which allows transfer of the agent across both cellular, intracellular organelle, and nuclear membranes. Compositions for nucleic acid delivery include nucleic acid, oil, oil-immiscible compound, noncationic surface active agent and essentially no cationic lipid, or include nucleic acid, oil, oil-immiscible compound and two noncationic surface active agents. The nucleic acid may be hydrophobically-modified, and be in combination with an oil, an oil-immiscible compound and at least one surface active agent. The compositions may be used for gene delivery to a cell, as well as delivery of other therapeutic agents.