Provided herein are, inter alia, compositions and methods useful for the in vivo delivery of bioactive agents (e.g., therapeutic or diagnostic agents). The compositions provided herein include cationic lipids, helper lipids and a biostability enhancing agent, which together form a lipid aggregate with the bioactive agent and allow for the systemic delivery of the bioactive agent to, for example, lung tissue without the requirement for biomolecular targeting.