Membrane Binding of poly(butylene oxide)-poly(ethylene oxide) Block Polymers

Poloxamers are a class of block polymers composed of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) segments. Due to their amphiphilicity, poloxamers can associate to unilamellar liposome membranes and influence properties such as membrane rigidity, fluidity, and permeability. They have also been used pharmaceutically to restore cell membrane integrity and to treat conditions such as Duchenne’s muscular dystrophy and ischemia reperfusion injury. This study investigates the effect of hydrophobicity on polymer/membrane binding. A series of PBO-b-PEO polymers with varying molar masses and compositions were synthesized using anionic polymerization. The critical micelle concentration of each polymer was determined using light scattering and dye solubilization experiments. Additional pulsed-field-gradient NMR and surface plasmon resonance techniques were used to compare the binding affinity of PBO and PPO systems.