Abstract: The present invention provides methods for loading of agents and substances into per-formed liposomes, preferably a suspension of pre-formed liposomes as well as to methods for the controlled quantum (step-wise) release of agents and substances from liposomes. One of the principle features of the methods of the invention is to expose the liposomes to ultrasound irradiation having predefined parameters, resulting in an increase in permeability of the liposomes, thereby permitting, respectively, the loading and/or release of agents and substances into and/or from the liposomes.