A porous reduced graphene oxide/chitosan-based nanocarrier as a delivery system of doxorubicin

Abstract

Nowadays, the concept of drug transmission is an important topic in the field of drug delivery research. Drug delivery is the method or process of administering a pharmaceutical compound to achieve a therapeutic effect in humans or animals. In this study, we report the development of a novel platform for the loading and release of doxorubicin (DOX). It is based on porous reduced graphene oxide (prGO) nanosheets and chitosan (CS) biocompatible polymer, where prGO can be dispersed in chitosan through amide linkages. The loading and release of DOX on the CS-prGO nanocomposite were investigated by voltammetry, FE-SEM, and FTIR and UV-Vis spectroscopy methods. We showed that chitosan-modified prGO (CS-prGO) was an extremely efficient matrix. An efficient loading of DOX (86% at pH 7.00, time 3 h and initial concentration of 0.5 mg mL^-1) was observed on CS-prGO as compared to the case of prGO due to the presence of the -OH and -NH₂ groups of chitosan. At the normal physiological pH of 7.00, approximately 10% of DOX could be released from CS-prGO in a time span of 1 h; however, when exposed to pH 4.00, 25% of DOX was released in 1 h. After 20 h, 18% and 62% of DOX was released at pH 7.00 and 4.00, respectively. This illustrates the major benefits of the developed approach for biomedical applications.

Fig. 1. Schematic for the preparation of the DOX/CS-prGO hybrid and its application in a drug delivery system.

Fig. 2. FE-SEM images of prGO (a), CS-prGO (b) and DOX/CS-prGO (c).

Fig. 3. (A) Cyclic voltammograms of 0.1 mM DOX at the GCE (a) and CS-prGO (b) and DOX/CS-prGO (c) modified GCE in 0.1 M PBS (pH 7.00) at 50 mV s⁻¹; (B) cyclic voltammogram of the DOX/CS-prGO modified GCE in 0.1 M PBS (pH 7.00) at the scan rates of (a) 10, (b) 25, (c) 50, (d) 75 and (e) 100 mV s⁻¹. (C) The plots of peak currents versus scan rate.

Fig. 4. UV-Vis spectra of prGO (a), CS (b), DOX (c) and DOX/CS-prGO (d).

Fig. 5. FTIR spectra of prGO (red), CS-prGO (violet) and DOX/CS-prGO (black).

Fig. 6. (A) The calibration curve of DOX absorbance vs. its concentration. (B) Comparison of the loaded DOX percent onto prGO and CS-prGO.

Fig. 7. (A) The effect of the pH of the PBS solution on the loading percent; (B) effect of shaking time on the loading percent; and (C) the release percent of DOX from CS-prGO in the PBS solution with pH 4.00 and 7.00.