Functionalization of surfactant templated magnetite by chitosan and PEGylated/Chitosan – In vitro studies on drug loading, release and anti-proliferative activity

Abstract

Magnetite iron oxide nanoparticles (MNPs) were synthesized using micro emulsion assisted co-precipitation method. The surface functionalization of MNPs was done with chitosan and PEGylated/chitosan and three samples of each were prepared. These materials were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron (SEM), and transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The Methotrexate (MTX) drug was then loaded on each functionalized MNPs as MCT-1–3 (chitosan; 0.1,0.5, and 1%) and MPCT-1–3 (PEGylated/chitosan (1% each with volume ratio 1:1, 3:1, and 1:3). Each composition showed maximum encapsulation efficiency (>95%). The pH dependent drug release studies were done under acidic (pH 5.0) and physiological (pH 7.4) conditions. These studies revealed consistent drug release and no burst release was observed from both functionalized MNPs. A comparatively delayed release from MPCTs than MCTs could be attributed to the formation of more compact sphere due to cross-linking of chitosan with PEG. The drug release was found greater at pH 5.0 for all functionalized MNPs. However, among all functionalized MNPs, maximum drug release was found to be 78.88% by MPCT-1 in acidic medium (pH 5.0). Cyclic voltametric (CV) analysis at slow scan rate (10 mV/s) further indicated controlled drug release and complimented the UV-findings. The MCF-7 (human breast cancer) cell line studies, however, indicated anticancer potential only for MPCT-1–3 with IC50 values ranging from 1.4 to 1.7 μM. Overall results pointed that methotrexate loaded PEGylated/chitosan coated magnetic nanoparticles MPCT-1 is the more compassionate material to be used as vehicle for controlled drug delivery.