Effective diuretic drug uptake employing magnetic carbon nanotubes derivatives: Adsorption study and in vitro geno-cytotoxic assessment

In this study, furosemide (FUR) adsorption was performed employing magnetic carbon nanotubes (CNT center dot Fe3O4) with different amounts of incorporated magnetite. The CNT and magnetic CNTs were synthesized by chemical vapor deposition (CVD) and co-precipitation methods, respectively. The nanoadsorbents were characterized by FTIR, XRD, Raman, SEM, and VSM techniques. The adsorption experiments revealed that the best performance was obtained by CNT center dot Fe3O4 1:10, showing values of 82.39% and 83.5 mg g-1 of removal percentage and maximum adsorption capacity at pH 2.0, due to the improvement in pi-pi interactions, and the presence of iron nanoparticles enhanced the adsorption, suggesting that cation-pi interactions control the process. The sorption process exhibited high dependence on pH, adsorbent dosage, and initial concentration of adsorbate. Sips and Elovich models showed the best adjustment for experimental data, suggesting that the process occurs on a heterogeneous surface and with different energy adsorption sites, respectively. The thermodynamic parameters indicated a spontaneous and exothermic process. The outcome of in vitro cytotoxicity assays revealed that the adsorbent/drug complex, after adsorption, exhibited lower toxic effects than the free drug. On the other hand, the genotoxicity assay showed that only the Fe3O4 caused damage at the DNA level. Magnetic carbon nanotubes prove to be efficient in the removal of furosemide from the aqueous solution. Also, the complex after adsorption showed good biocompatibility, allowing a promising application in the biological area and stimulating future studies in drug repositioning.