Nanostructured hybrids derived from clays are materials of increasing interest based on both structural characteristics and functional applications, including environmental and biomedical uses. This review introduces some recent examples of nanostructured clay derivatives (organoclays) useful as adsorbents or photocatalysts for environmental applications such as the removal of pollutants or development of environmentally oriented pesticide formulations. The second group of nanostructured materials considered here are related to the so-called bio-nanohybrids, formed by combination of an inorganic solid (clay mineral) with organic entities from biological origin at the nanometric scale. Bionanocomposites are an emerging group of nanomaterials resulting from the assembly of different clay minerals and biopolymers. Among the proposed applications, the development of novel hybrid materials for scaffolds and regenerative medicine, as well as new substrates to immobilize biological species from enzymes to viruses, is notable. Hybrid materials based on layered double hydroxides are receiving special attention in view of the possible applications as drug delivery systems.

The present work introduces new hybrid materials based on the combination of layered double hydroxides (LDH) and two biopolymers (a protein and a polysaccharide) to produce LDH–biopolymer nanocomposites, able to act as effective drug delivery systems (DDS) in comparison to the LDH or the biopolymers alone. Ibuprofen (IBU) has been chosen as a model drug, being intercalated in a Mg–Al LDH matrix. The resulting hybrid is used to prepare bionanocomposite materials by association with two biopolymers: (i) zein, a highly hydrophobic protein, and (ii) alginate, a polysaccharide widely applied for encapsulating drugs. Characterization of the IBU/Mg–Al LDH intercalation compound and the bionanocomposites resulting from its incorporation into alginate–zein matrices of different composition was carried out by means of different experimental techniques: X-ray diffraction, infrared spectroscopy, chemical and thermal analysis, as well as optical and scanning electron microscopies. Preliminary kinetic studies of IBU liberation from bionanocomposites processed as beads show a better protection against drug release at the stomach pH and a controlled liberation in the intestinal tract conditions. This effect can be attributed to the hydrophobic nature of zein, which limits the passage of water and swelling of biocomposite beads prepared with such systems, delaying the release of the drug.