Abstract: Particles which enclose cavities can be produced by adding a water-insoluble solid, liquid or gaseous cavity generating compound to an aqueous solution of a matrix material. Subsequent to forming particles by dispersion in a water-insoluble dispersion medium, the matrix is rendered insoluble in water by cooling, by covalent cross-linking or by polymerization. The cavity generating compound is washed out, whereafter the particles can be used as ion exchangers in gel filtration processes, in hydrophobic chromatography or in affinity chromatography, optionally subsequent to derivatizing the particles. The particles can also be used to advantage as microcarriers in the cultivation of anchorage dependent cells.