Triphenylphosphonium Bolaamphiphile-Liposomes Loaded with Resveratrol and Trolox: Mitochondriotropic Formulations with Therapeutic Potential in Neurodegeneration and Cancer

Purpose: We aimed to develop mitochondriotropic liposomes (TPP3-liposomes) formulated with a phospholipid (PC) and thetriphenylphosphonium bolaamphiphile TPP3, and encapsulate two antioxidants, trans-resveratrol (hydrophobic) and Trolox (hydro-philic), for mitochondrial therapy of neurodegeneration and drug-resistant tumors.Methods: The influence of the PC (saturated or unsaturated) and TPP3/PC ratio on liposome physico-chemical properties (diameter,polydispersity, charge, transition temperature, and stability over time) were investigated by Dynamic and Dielectrophoretic LightScattering measurements. Evaluation of cytotoxicity, mitochondrial targeting and effect on mitochondrial membrane potential ofTPP3-liposomes were conducted utilizing an MTT assay, laser scanning confocal microscopy and flow cytometry on drug-resistanthuman breast cancer cells (MDA-MB231) and murine skeletal muscle cells (C2C12): MDA-MB231 cells have been selected asa model for studying multiple drug resistance (MDR) in cancer; C2C12 cells have been chosen to investigate the oxidative stressassociated with the ageing process and neurodegenerative muscle diseases. Two different strategies were explored for antioxidantloading: active loading into the liposome aqueous cavity (resveratrol, Trolox) and passive loading inside the lipid bilayer membrane(resveratrol).