[0016] (Hybrid) Beads according to the invention are advantageously prepared through a coacervation process which relies on the decrease in solubility of the hybrid sol containing one or more silica precursor(s) and an alginate solution, due to the addition of a silica concentrator (such as a polycationic organic polymer). In fact, the alginate acts as a template and the silica concentrator plays both the role of a concentrator of silicate and that of a catalyst to accelerate the hydrolysis and polycondensation of silica precursor(s) at the periphery of the bead, thus creating a porous crust (shell). The core of the beads is composed of a sodium alginate-silica composite in which components or bioactive substances, such as enzymes, organelles such as thylakoids, vacuoles, chloroplasts, vesicles, or living cells are encapsulated (entrapped). The obtained external layer (shell) of the bead is formed of a porous layer of silica concentrated by the silica concentrator.