synthesis and characterization of mnps hydrogel with ph-responsiveness properties to release diclofenac sodium as a model drug

In the present study, the loading and releasing of diclofenac sodium (ds) were investigated using a ph-sensitive magnetic nanocomposite hydrogel. the hydrogel was prepared through grafting copolymerization of acrylic acid (aa) and acrylamide (aam) and using ammonium persulfate (aps) as a free radical initiator in the presence of fe3o4@sio2@ (3-aminopropyl) trimethoxysilane (aptms)@maleic anhydride (man) as a cross-linker. the nanocomposite hydrogel structure (fe3o4@sio2@aptms@man) was confirmed as the result of xrd, vsm, ft-ir, sem, eds, and tem spectroscopy techniques. furthermore, thermal properties were deliberated using tga and dtg. the effects of different parameters such as ph, time, fe3o4@sio2@aptms@man content, and salt solutions on swelling behavior were investigated considering the abovementioned outcomes. the adsorption isotherm was studied at 25°c using langmuir, freundlich, and temkin. the adsorption data were well described by the langmuir isotherm model. a kinetic study revealed the applicability of pseudo-first-order and pseudo-second-order models for the adsorption of mentioned ds. moreover, the ph sensitivity of nanocomposite hydrogel and loading/releasing drugs were studied. examining in vitro drug release in different buffer solutions indicated that the ph of the solution could mainly lead to the ds drug-releasing behavior of hydrogel. however, the cumulative release ratio of ds in ph: 7.4 solutions reached up to 93% within 120 min. consequently, the investigated nanocomposite hydrogel of this study (fe3o4@sio2@aptms@man) can be applied in widespread biomedical applications, particularly for controlled, targeted drug delivery purposes.