Synthesis of magnetic field sensitive hydrogels and investigation of drug release behaviors

Within the scope of the thesis, magnetic field responsive poly (NIPAAm-co-VSA)-rGO/Fe3O4 IPN hydrogel composites (Ferrogels) containing different amounts of reduced graphene oxide (rGO) in its structure were synthesized. For this, firstly, poly (NIPAAm-co-VSA)-rGO IPN hydrogels which can be deswelling depending on temperature were synthesized. Then, ferrogels containing Fe3O4 nanoparticles were synthesized by the in situ reduction method by impregnating Fe2+/3+ ions in order for the hydrogels to show heating behavior under an alternating magnetic field (AMF). Structural characterizations of synthesized rGO were performed using XRD, EDX and mapping analysis techniques. Structural characterizations of poly (NIPAAm-co-VSA)-rGO/Fe3O4 ferrogels were performed using FT-IR, XRD, SEM, EDX, mapping and VSM analysis techniques. Doxorubicin (DOX) drug was loaded to the synthesized ferrogels by solution impregnation method and their heating and drug release behavior over time under magnetic fields of 1.37, 1.64 and 1.91 millitesla (mT) intensities were investigated. For this, drug loading capacities Qkap, amount of drug released per mass of dry polymer at any time qt (mg DOX/g polymer), amount of drug release at equilibrium qd, rate of drug release qv (mg DOX / min) and percent of drug release at equilibrium Qd characteristics were calculated. In all drug release studies using ferrogels, it has been determined that the drug release behavior of synthesized magnetic field and temperature responsive ferrogels under AMF is directly related to the amount of rGO and thus Fe3O4 in the structure. Keywords: Ferrogels, Magnetic field responsive hydrogels, Controlled drug release, Induction heating