Carbon nanotubes/ordered mesoporous carbon/chitosan nanocomposite as a promising carrier for everolimus targeted delivery toward lung cancer cells

Abstract

Lung cancer is the leading cause of cancer deaths worldwide. Everolimus (Eve) was observed to upregulate the expression of phosphatase and tensin homolog and microRNA-4328 and inhibits the proliferation and migration of A549 cells. In the present study, a new nanocarrier based on composite containing chitosan (CS), carbon nanotubes (CNT) and ordered mesoporous (OMC) was used to load the anticancer drug everolimus (EVE). The existence of EVE on CNT/OMC/CS nanocarrier is confirmed by FE-SEM images, Raman, UV-Vis, FT-IR, BET and TGA analyses. The results showed that the introduction of CS improved the drug loading by 89.4% at pH 7.0, time 2 h and EVE to CNT/OMC/CS ratio of 1.5. Moreover, release study of EVE showed that 15.2% of EVE is released from EVE@CNT/OMC/CS at pH=7.4 for 15 h, while 78.9% of EVE is released at pH = 4.5. After 25 h, 16.8% and 88.0% of EVE were released at pH 7.4 and 4.5, respectively. Based on the MTT assay results, CNT/OMC/CS exhibited negligible cytotoxicity and good compatibility on the A549 lung cancer cell line. The cytotoxicity of the EVE@CNT/OMC/CS (IC50 of ~9 μg/mL) on the A549 cell line was higher as compared to free Eve drug (IC50 of ~13 μg/mL) after 48 h exposure time. All the data confirmed the synergistic effect of EVE in combination with CNT/OMC/CS could serve as an ideal candidate in treating lung cancer.

Fig. 1

Raman spectra of CNT, OMC, CNT/OMC, CNT/OMC/CS, and EVE@CNT/OMC/CS

Fig. 2

UV-Vis spectra of aqueous solutions of EVE (90 ppm), CNT, OMC, CS, and EVE@CNT/OMC/CS with concentration of 1 mg/mL

Fig. 3

FE-SEM images of a CNT, b OMC, c CNT/OMC, d CNT/OMC/CS and e EVE@CNT/OMC/CS

Fig. 4

FT-IR spectra of CNT/OMC and EVE@CNT/OMC/CS

Fig. 5

a TGA curves of CNT/OMC/CS and EVE@CNT/OMC/CS; b Cyclic voltammograms of CNT/OMC, CNT/OMC/CS and EVE@CNT/OMC/CS modified CPE using [Fe(CN)₆]^3-/4- (2 mmol L⁻¹)/PBS (0.1 mol L⁻¹); c Nitrogen adsorption-desorption isotherm of CNT/OMC/CS and EVE@CNT/OMC/CS

Fig. 6

a The calibration curve of EVE absorbance to its concentration; b Comparison of the loaded EVE percent onto CNT, OMC, CNT/OMC and CNT/OMC/CS; c Effect of time on loading percent in 0.1 mol L⁻¹ PBS (pH 7.0) at room temperature and time of 2 h; d The pH effect of 0.1 mol L⁻¹ PBS solution on loading percent at room temperature and time of 2 h

Fig. 7

a The release percent of EVE from EVE@CNT/OMC/CS in 0.1 mol L⁻¹ PBS solution with pH 4.5 and 7.4 at 25 °C temperature and different times; b The concentration effect of PBS with pH 4.5 on release percent at 25 °C temperature and time of 15 h; c The temperature effect of 0.1 mol L⁻¹ PBS with pH 4.5 on release percent at time of 6 h; d The cell viability of A549 cells after treatment with 50 μg/ml EVE, CNT/OMC/CS and EVE@CNT/OMC/CS for 48 h

Fig. 8

The cell viability of A549 cells after treatment with various concentrations of EVE and EVE@CNT/OMC/CS for 24 and 48 h