Design of psyllium-g-poly(acrylic acid-co-sodium acrylate)/cloisite 10A semi-IPN nanocomposite hydrogel and its mechanical, rheological and controlled drug release behaviour.

Soft biomaterials derived from polysaccharides are generally suffers from lack of mechanical robustness and instability. The naturally occurring highly abundance low cost polysaccharide has immense aspect as biomaterial after functionalization which can be designed as stretchable and rubber-like elastic with reversible ductility. A highly swellable, stretchable, low creep, non-cytotoxic nanocomposite hydrogel has been fabricated by simple one-pot Michael type covalent grafting of acrylic acid based copolymer onto psyllium biomacromolecular chian by free radical gelation technique. The fabricated hydrogel was rheologically tested which implies its viscoelastic and thixotropic like features. The porous morphology of the hydrogel was confirmed by scanning electron micrograph. The cryo-transmission electron micrograph shows the random dispersion of the nanoclay (cloisite 10A) tactoids in exfoliated as well intercalated forms. These random distributions of clay nanosheets also enhance the mechanical toughness and reversible ductility of the hydrogels which was also supported by the mechanical and loading-unloading cycle measurement. Nonetheless, the nanocomposite hydrogel was non-cytotoxic against human cell-line (human osteosarcoma) and shows good cell attachment of live cells in a 5-day 'live-dead' assay with almost negligible quantity of cell death. These attributes can promote this material as a soft biomaterial for controlled release device with mechanical robustness and rubber-like elasticity.