Compositions and methods use the gel-forming properties of microporous particles to create useful formulations combining two free-flowing materials to produce a hydrogel mass. The free-flowing materials preferably provide dry microporous particles (preferably as an aerosol) that may contain additional agents, and a second composition of a fluid material which is an aqueous solution of one or more high molecular weight polymers capable of forming a hydrogel upon further concentration and/or reaction. The hydrogels can be preferably formed on a surface by spraying the two compositions as fluids together in the proper ratio onto the surface.
