In one aspect, the invention provides a method for treating a protein-containing surface, including applying to the surface a microcapsule suspension including droplets of a dispersed water-immiscible core phase, an aqueous continuous phase, and a wall surrounding each core phase droplet, the wall including the salt formed from at least one amphiphilic Lewis acid reactant or amphiphilic Lewis base reactant, and at least one corresponding Lewis base reactant or Lewis acid reactant.