• 2019-07
  • 2019-08
  • 2019-09
  • 2019-10
  • 2020-03
  • 2020-07
  • 2020-08


    Fig. 3. A) The SDS-PAGE images of the gel after Coomassie blue staining. Lane 1: molecular markers; Lane 2: Cetuximab only; Lane 3: Dox-NPs (negative control); Lane 4: Dox-NPs-Cet. B) The stability of Dox-NPs-Cet in 0.01M Tris-HCl (pH7.4) at two different temperatures.
    Fig. 4, Dox-NPs-Cet were internalized into A549 cells. The nano-particles can be clearly observed both at the cell membrane and in vesicles in the cells. Arrows are used to show typical examples of the localization of Dox-NPs-Cet targeting nanocarriers within the cells. Fig. 4A represents control cells untreated with nanoparticles. As shown in Fig. 4B, aggregated particles were found on the surface of the cell membranes. This might be due to the specific targeting of the EGFR with the monoclonal antibody Cet. However we only observed Dox-NPs-Cet on parts of the cell membranes. In Fig. 4C, proof of cellular uptake of the Dox-NPs-Cet is visible on the TEM image. The nano-particles are present in cellular vesicles. In Fig. 4D, larger MDMB-FUBINACA M1 of particles are found in the cells. These results indicate that the small sized nanoparticles were MDMB-FUBINACA M1 efficient in targeting the cells and were easily internalized in endosomes.
    3.4. In vitro cytotoxicity of dextran-coated Fe3O4 nanoparticles, Dox-NPs and Dox-NPs-Cet
    As shown in Fig. 5, when treated with dextran-coated Fe3O4 nano-particles in the concentration range of 25–1000 µg/mL, viability of the A549 cells exceeded 85% at all concentrations (Fig. 5A). This demon-strates that dextran-coated Fe3O4 nanoparticles have a good bio-compatibility with A549 cells. When cells were co-cultured with Cet alone (Fig. 5B), cell viability was affected slightly and there was no statistically significant difference between the various concentrations
    Fig. 4. Representative TEM images of A549 control cells and A549 cells treated with Dox-NPs-Cet in modified RPMI-1640 at 37 °C for 3 h. Nanoparticles were located at the cell membrane and in intracellular ve-sicles in which they form large aggregates. Arrows are used to show typical examples of the localization of Dox-NPs-Cet targeting nanocarriers within the cells. A) Control cells, not treated. B) Nanocarriers con-centrate near some sites of the plasma membrane. C) A typical example of nano-carriers concentrated in an intracellular ve-sicle (arrow). Some particles can also be seen in the vicinity of the plasma mem-brane. D) Typical examples of large ag-gregates of nanocarriers concentrated in endosomes (arrows).
    and culture times. However, when incubated with Dox-NPs or with Dox-NPs-Cet a significant reduction of the viability of the A549 cells followed and this was already the case after 24 h. Stronger inhibition could be observed after 48 h. The IC50 value of Dox-NPs-Cet at 48 h (0.22 µg/mL) is much lower than that of Dox-NPs (0.68 µg/mL), in-dicating that conjugating Dox-NPs with Cet significantly increases the cytotoxicity of Dox-NPs (Fig. 5C, D).
    4. Discussion
    In this report, we synthesized co-conjugates of Cetuximab and Doxorubicin loaded on dextran-coated Fe3O4 magnetic nanoparticles (Dox-NPs-Cet) as novel targeted nanocarriers for potential use in non-small cell lung cancer treatment. The chemical composition and phy-sicochemical properties of the co-conjugates were analysed by FTIR, VSM, DLS, and SDS-PAGE. Coating of dextran-coated Fe3O4 magnetic nanoparticles with Dox and Cet was shown to be successful. The co-conjugated particles were shown by TEM to have an appropriate hy-drodynamic size of 144.5 nm, in the range of 100–200 nm, which al-lowed them to easily enter into the cell [34]. Large aggregates of Dox-NPs-Cet were found in the cells. Dox-NPs-Cet show cytotoxicity effects on A549 cell, a NSCLC cell line expressing the wild-type EGFR. The cytotoxicity test demonstrated that Cetuximab loaded Dox-NPs sig-nificantly reduced the cell viability in a dose-dependent manner. While the dextran-coated Fe3O4 magnetic nanoparticles were biocompatible with A549 cells and showed no concentration dependent cytotoxic ef-fects.
    As a delivery system in relation to Doxorubicin and Cetuximab, the dextran-coated Fe3O4 magnetic nanoparticles provided a large solid surface for drug loading. This could improve the drugs pharmacoki-netics and biological distribution [36]. Furthermore, magnetic nano-particles greatly facilitated the co-conjugate preparation process which is an important factor for a good anticancer nanomedicine [37].
    As mentioned above, the majority of patients with NSCLC present with already locally advanced or metastasised disease at the moment of diagnosis. Local treatments including surgery and radiotherapy and their combinations, very effective for local disease, are therefore