pH-dependent permeability change and reversible structural transition of PEGylated polyion complex vesicles (PICsomes) in aqueous media

The acidic pH-sensitivity of polyion complex vesicles (PICsomes) was investigated, using dynamic light scattering (DLS) and confocal laser scanning microscopy (CLSM). PICsomes showed pH-dependent and reversible structural transition, and also underwent a change in permeability by sensing acidic pH. Increased membrane permeability at the pH corresponding to cellular endosomes may be useful for future applications of PICsomes as a delivery vehicle of biologically active compounds to intracellular compartment.