Organically modified silica (Ormosil) gels are three-dimensional matrices obtained by co-polymerizing
tetraalkyl orthosilicates and organoalkoxysilanes through the sol-gel technology. Ormosil matrices are highly flexible
with respect to macroscopic size and shape, as they can be prepared in the form of monoliths, layers, powders
and nanoparticles, and to their physical-chemical properties, with special regard to hydrophobicity or specific functionalization
of their alkyl and aryl groups. This makes Ormosils a very promising matrix, though not widely exploited
so far, for the immobilization of enzymes and other biomolecules either by encapsulation within the gel matrix
or by surface decoration of nanoparticles. Potential applications range from the development of biocatalysts and bioremediation devices
to intracellular drug delivery and photodynamic therapy.