Abstract
The study investigates curcumin/SPIONs hybridized mesocellular foam type silica for potential dual purpose of drug delivery (curcumin) and magnetic resonance imaging. Magnetization capability and curcumin release was assessed for different structured silica such as spherical silica (Q-10), Si-MCM-41, Si-SBA-16, mesocellular foam (MSU-Foam), Si-KIT-6, ULPFDU-12, and silicalite. The phase, textural, and morphological variation was systematically scrutinized using various physico-chemical techniques. Ten weight percent SPIONs loading was found to generate magnetically active SPIONs in the following order: Q-10 (1.44 emu/g) > SBA-16 (0.80 emu/g) > MSU-Foam (0.24 emu/g) > Si-MCM-41 (0.07 emu/g) > Si-KIT-6 (0.07 emu/g) > silicalite (0.08 emu/g), respectively. The iron oxide dispersion, specific surface area, and porosity play a major role in various structured silicas. MSU-Foam with wormhole structure showed highest specific surface area occupation of SPIONs (73%). The presence of interconnected porosity of foam tends to generate external agglomeration of SPIONs (7–18 nm) at the pore surface contributing to expansion of pore sizes from 16.4 to 40.2 nm. The SPIONs over spherical micron-sized silica Q-10 showed the formation of large nanoclusters (10–25 nm). Thirty to 390 μg/ml of curcumin was loaded over silica and SPIONs/silica structured hybrid, and drug release was studied at pH 5.6 for 72 h. SPIONs/MSU-Foam with less magnetization showed the highest cumulative curcumin release (53.2%), while Q-10 spherical silica with high magnetization property showed less cumulative release of curcumin (12%).