Surfactant-mediated sub-nanostructure engineering of morphology-tailored magnesium fluoride derivatives for resistant bacterial wound repair

Controlled synthesis of subnano-sized magnesium fluoride (MgF 2 ) and its multi-element derivatives remains a critical challenge limiting their functional exploitation. Here, we develop a mild colloidal chemical synthesis strategy to fabricate uniform MgF 2 , NaMgF 3 , and KMgF 3 sub-nanocrystals with tunable morphologies (nanorods, nanoneedles, nanosheets) and precise size control by regulating nucleation and growth processes using surfactants with distinct functional groups. The synthesis mechanism involves surfactant-mediated interaction between metal trifluoroacetate precursors and surfactants (oleic acid, oleylamine), followed by fluorination upon thermal decomposition of the formed intermediates. Oleic acid promotes anisotropic one-dimensional (1D) growth through carboxyl-Mg 2+ coordination on specific facets, while oleylamine modulates growth kinetics by balancing crystal plane energies, enabling diverse sub-nanostructures. Structure-activity relationship analysis reveals that KMgF 3 nanorods exhibit superior antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) by impairing bacterial proton motive force. In vivo studies confirm that treatment with these nanorods accelerates the healing of infected wounds, an effect linked to concurrent infection control and tissue regeneration. This work highlights the critical role of surfactant regulation in sub-nanostructuring MgF 2 derivatives, paving the way for advanced biomedical applications.