tThe present article deals with preparation of pH responsive nanohydrogels based on tragacanth gum (TG)biopolymer for drug delivery. The nanohydrogels were prepared using different chemical reagents suchas 3-aminopropyltriethoxysilane (APTES) modifier and glyceroldiglycidylether (GDE), polyvinyl alcohol(PVA), and glutaraldehyde (GA) as cross-linkers. The obtained nanohydrogels were characterized usingdifferent techniques such as scanning electron microscope (SEM), elemental analysis, FT-IR, zeta sizer andthermogravimetric analysis (TGA). The gel content increased with increasing the cross-linkers contentsand reached to a maximum of 90%. The swelling behavior of nanohydrogels was investigated in termsof the effect of pH (2.2, 7.4 and 9), temperature (27, 37 and 60◦C), and reaction time (2–24 h). Loadingof Indomethacin (IND) as a model drug showed dependence on the network structure of nanohydrogels.The total in vitro IND release showed dependence on the network structure of nanohydrogels and was inthe range of 50–80% at pH 9 after 24 h.
