Designing silver nanoparticles impregnated acacia and tragacanth gum based copolymeric hydrogels for drug delivery applications

Abstract

The current study investigates the utilization of gum acacia (GA) & tragacanth gum (TG) for the synthesis of silver nanoparticles (NPs) and their subsequent incorporation into hydrogels for potential applications in drug delivery (DD). Cefoperazone, an antibiotic drug, was encapsulated into hydrogels to enhance their antimicrobial activity. Copolymers were characterized by UV–Vis, TEM, FESEM, AFM, XPS, XRD, FTIR, TGA and DSC techniques. UV–Vis spectroscopy revealed the formation of NPs at a wavelength of 436 nm with an optical density of 2.65. TEM images depicted AgNPs with an average size of 37.29 ± 7.25 nm with their uniform distribution. XRD analysis demonstrated distinct crystalline peaks at 2θ = 38.34o, 43.80o, 64.60o and 77.42o attributed to AgNPs. XPS peaks observed at 368 & 374 eV, corresponding to the 3d5/2 and 3d3/2 modes of silver, respectively, confirmed the incorporation of AgNPs in the polymer matrix. Hydrogels demonstrated pH responsive sustained release of cefoperazone. The diffusion mechanism was non-Fickian and described by the Higuchi kinetic model. In the DPPH assay, copolymers exhibited a 32.36 % inhibition of free radicals, whereas in the F–C reagent assay, antioxidant activity was measured as 22.25 μg equivalent of gallic acid. The copolymers displayed blood compatible nature, as evidenced from haemolysis (2.11 ± 0.03 %) and thrombogenicity (74.71 ± 1.63 %) results. The interactions of copolymer with intestinal membrane attributed to mucoadhesive properties and required detachment force of 55.30 ± 2.80 mN to separate from the biological membrane. Growth of E. coli, P. aeruginosa and S. aureus bacteria was inhibited by copolymers with and without antibiotic drug. These characteristic properties of copolymers make them ideal materials for DD carriers.