Bioresponsive inulin‐azobenzene nanostructures for targeted drug delivery to colon

Abstract Here, a series of amphiphilic inulin‐azobenzene (IAb) conjugates has been synthesized by the reaction of inulin, a naturally occurring polysaccharide, with varying amounts of 6‐(3‐(4‐[4‐dimethylaminophenylazo]‐phenyl)‐thioureido)‐hexanoic acid (Azo‐ahx), an azobenzene linker. The resulting IAb conjugates (IAb‐1, IAb‐2 and IAb‐3 with 1, 3, and 5% substitution of the linker, respectively) self‐assembled into nanostructures in aqueous environment, which were then used to encapsulate the hydrophobic drug molecules, ornidazole (OZ) and 5‐fluorouracil (FU). Drug loaded and unloaded nanostructures were subjected to characterization by spectroscopic and dynamic light scattering (DLS) techniques. The sustained drug release behavior of these nanostructures was studied by dialysis bag method at different pH values. Enzyme‐responsive drug release behavior was investigated under the influence of inulinase. Besides, the best formulation, IAb‐1, not only showed antioxidant potential but also exhibited good wound healing properties as evidenced by in vitro scratch assay in HaCaT cells. The self‐assembled nanostructures of IAb‐1 were found be non‐toxic to cells even up to 700 μg/ml as tested by MTT assay on HEK 293 and HeLa cells. In conclusion, the potential of self‐assembled drug loaded inulin‐azo nanostructures has been demonstrated for the targeted drug delivery applications.