Development and Evaluation of Crocetin-Functionalized Pegylated Magnetite Nanoparticles for Hepatocellular Carcinoma

Abstract

Liver cancer remains among the leading causes of cancer-related deaths worldwide. This is due to many reasons, including limitations of available drugs, late diagnosis due to the overlapping symptoms with many other liver diseases, and lack of effective screening modalities. Compared to conventional chemotherapy, targeted drug delivery systems are advantageous in many ways, as they minimize drug resistance and improve therapeutic value for cancer patients. Nanomaterials, in general, and nanoparticles, in particular, possess nm size, which provides a high surface area for a great extent of functionalization to be used for the targeted delivery of cancer drugs. Amongst the different formulations of nanoparticles, magnetic nanoparticles (MNPs) have unique chemical and physical characteristics and magnetic behavior, making them preferable candidates as a core for drug delivery systems. To maintain the nanosized structure of MNPs, a polymeric coating is usually applied to maintain the nanoparticles dispersed in the solution. Moreover, the polymeric coating provides a plate form for carrying drug molecules on its surface. In the present study, poly(ethylene glycol) (PEG)-coated MNPs were successfully synthesized, where the optimum concentration of PEG on the surface of the MNPs was investigated. The PEG-coated MNPs were further coated with crocetin at different concentrations. The crocetin-coated pegylated MNPs were evaluated in vitro using a hepatic cell line (HepG2) for up to 72 h. Results showed good release kinetics under acidic and neutral conditions. The optimally prepared drug delivery system showed a high potential for reducing the HepG2 cell proliferation in vitro using an MTT assay. The calculated IC50 for Cro-PEG-MNPs were 0.1019, 0.0903, and 0.0462 mg/mL of 5×, 10× and 20×, respectively.

Keywords: PEG; crocetin; hepatocellular carcinoma; magnetite nanoparticles.

Figure 1

(a) XRD pattern, (b) FT-IR spectrum, (c) TGA thermogram, (d) magnetization thermogram, and (e) TEM micrograph of the as-prepared magnetite nanoparticles.

Figure 2

(a) XRD patterns of the PEG-coated MNPs as a function of the concentration of PEG, (b) FT-IR spectra of the PEG-coated MNPs as a function of the concentration of PEG, (c) TGA thermograms of the PEG-coated MNPs as a function of the concentration of PEG, (d) the extent of coating of MNPs with PEG as depicted from their TGA thermograms.

Scheme 1

Mechanism of the formation of PEG and hydrated layers onto MNPs surfaces.

Figure 3

TEM micrographs of PEG-coated MNPs as a function of [PEG]: (a) 0%, (b) 1.5%, (c) 3.0%, (d) 4.5%, (e) 6.2%, (f) 9.0%, (g) 12.0%, and (h) 18.5% by weight, and (i) average particle size distribution as depicted from the TEM micrographs.

Figure 4

Magnetization hysteresis of the as-prepared PEG-coated MNPs as a function of the concentration of PEG.

Figure 5

FT-IR spectra of the crocetin-functionalized PEG-coated MNPs as a function of the concentration of crocetin.

Figure 6

(a) TGA thermograms of the crocetin-functionalized pegylated MNPs as a function of the concentration of crocetin, (b) TGA thermograms of pure PEG and crocetin.

Scheme 2

Representation of the possible binding mechanism of crocetin to PEG-MNPs.

Figure 7

Cumulative release study of crocetin-functionalized pegylated MNPs at different pH values: (a) 5×-Cro-PEG-MNP, (b) 10×-Cro-PEG-MNPs, (c) 20×-Cro-PEG-MNP.

Figure 8

(a) Cell viability of HepG2 cells against pure crocetin as a function of the concentration of crocetin after 24 h of culture at 37 °C. (b) Cell viability of HepG2 cells against pure crocetin after 72 h of culture at 37 °C. (c) Cell viability of HepG2 cells against crocetin-functionalized PEG-coated MNPs after 24 h of culture at 37 °C. (d) Cell viability of HepG2 cells against crocetin-functionalized PEG-coated MNPs after 72 h of culture at 37 °C.