Synthesis, characterization, and reusability of novel nanobiocomposite of endophytic fungus Aspergillus flavus and magnetic nanoparticles (Fe3O4) with dye bioremediation potential.

The incorrect disposal of textile dyes, such as Reactive Black 5 (RB5), causes several problems for living beings and the quality of the environment. Nanobiocomposites (NBC) produced from endophytic fungi (potentially remediation dyes-agents) and magnetic nanoparticles have high biotechnological potential due to their superparamagnetic behavior, which would allow their recovery through the magnetic field after the bioremediation process. This work aimed to obtain a new nanobiocomposite from the interaction of magnetite nanoparticles (Fe3O4) with the endophyte Aspergillus flavus (Af-CL-7) to evaluate its bioremediation capacity and to reduce the toxicity of RB5 and its reuse. Before obtaining the NBC, Af-CL-7 showed discoloration of RB5 and it was tolerant to all tested concentrations of this dye. The discovery of the nanobiocomposite textile dye bioremediator product presents a significant environmental advantage by addressing the issue of water pollution caused by textile dyes. The NBC called Af-Fe3O4 was successfully obtained with the magnetized endophyte, and their magnetic properties were verified by VSM analysis and by action of magnetic fields generated by Nd-Fe-B magnets SEM analyzes showed that the nanoparticles did not cause any damage to the hypha morphology, and TEM analyzes confirmed the presence of nanoparticles in the fungus wall and also inside the cell. The NBC Af-Fe3O4 and Af-CL-7 showed, respectively, 96.1% and 92.2% of RB5 discoloration in the first use, 91.1% e 86.2% of discoloration in the validation test, and 89.0% in NBC reuse. In the toxicological bioassay with Lactuca sativa seeds, NBC showed a positive reduction in the toxicity of RB5 after treatment, allowing the hypocotyl growth to be statistically similar to the control with water. Thus, we highlight the promising obtaining process of NBC that could be applied in bioremediation of contaminated waters, wherein the industrial economic cost will depend on the fermentation efficiency, biomass production and nanoparticle synthesis.

Doxorubicin-Loaded Iron Oxide Nanoparticles Induce Oxidative Stress and Cell Cycle Arrest in Breast Cancer Cells.

Cancer is one of the most common diseases nowadays and derives from the uncontrollable growth of a single cell. Magnetic nanoparticles (NpMag) offer various possibilities for use in the biomedical area, including drug delivery mediated by magnetic fields. In the current study, we evaluated the in vitro effects of iron-oxide magnetic nanoparticles conjugated with the antitumor drug doxorubicin (Dox) on human breast cancer cells. Our results revealed that magnetic nanoparticles with Dox (NpMag+Dox) induce cellular redox imbalance in MCF-7 cells. We also demonstrate that iron-oxide nanoparticles functionalized with Dox induce oxidative stress evidenced by DNA damage, lipid peroxidation, cell membrane disruption, and loss of mitochondria potential. As a result, NpMag+Dox drives MCF-7 cells to stop the cell cycle and decrease cell migration. The association of NpMg+Dox induced a better delivery of Dox to MCF cells, mainly in the presence of a magnetic field, increasing the death of MCF cells which might reduce the toxicity for healthy cells providing a better efficacy for the treatment. Thus, iron-oxide nanoparticles and doxorubicin conjugated may be candidate for anticancer therapy.