Multifunctional magnetic nanocarrier: synthesis, characterization and pH-responsive doxorubicin release profile

Abstract

In this study, carboxymethyl cellulose (CMC) functionalized superparamagnetic iron oxide nanoparticles (SPIONs) have been synthesized as a novel theranostic platform which enables magnetic resonance (MR) imaging-guided and pH-responsive targeted drug delivery. In order to build up this platform, firstly, polyethyleneimine (PEI) modified SPIONs with the size of 15 nm in diameter have been preapared by coprecipitation technique. Then, the free amine groups on the PEI-SPIONs surface has been further functionalized covalently with CMC by the catalysis of N,N'-dicyclohexylcarbodiimide (DCC) and N,N'-dimethylpyridin-4-amine (DMAP) coupling to produce CMC-SPIONs. After the surface modification of PEI-SPIONs with CMC, the saturation magnetization just decreased from 60 to 58 emu/g compared to PEI-SPIONs which indicated that the CMC-SPIONs could be used as T1 agent in MRI. The resultant CMC-SPIONs have been loaded with a well-known anti-tumor durg Doxorubicin (Dox) and investigated its loading and releasing profiles from the nanocarrier. The CMC acted as an excellent nanocarrier for Dox with a loading efficinecy ≈ 86%. The drug releasing profile has been studied at different pH values (3.5; 5.5; and 7.4). The results show that when the pH of the release medium (phosphate buffer solution) was changed from 7.4 to 5.5 or 3.6, the Dox release has been incereased which indicates that the Dox releasing is pH dependent for the developed platform. The study provides a method to fabricate a multifunctional magnetic nanocarrier platform without loosing its magnetic efficiency during functionalization process and may utilize for biomedical imaging and cancer therapy.