Insulin-Loaded Graphene Oxide Microparticles: Synthesis, Characterization, Insulin Delivery, and Physical Interactions Analysis

The graphene oxide (GO) microparticles were synthesized through ultrasonication for insulin delivery. The prepared GO microparticles and insulin-loaded GO/insulin composite were characterized by various techniques including ATR-FTIR (attenuated total reflection flourier transformed infrared spectroscopy), scanning electron microcopy (SEM), thermogravimetric analyzer (TG), zeta potential and dynamic lights scattering (DLS) measurements. The particle size analysis showed that the GO particle was well distributed, and the size was about 4 mu m with surface charge of -27.5 mV in MES solution (pH 4.7). SEM images showed that insulin successfully attached on surface of GO particles. The GO particles exhibited excellent insulin loading efficiency in lower pH solution (2.5, 4.7). The release study showed that insulin was released from GO/insulin composite in higher pH solution (7.4). This study provides valuable information for development of insulin carriers based on GO.