(650c) Aloe Vera-Mediated Green Synthesis of Tellurium Nanostructures with Both Antimicrobial and Anticancer Activity

Antimicrobial resistance to antibiotics is a huge concern that presents significant challenges to modern healthcare. Thus, an alternative solution that does not require the use of antibiotics is needed. One of the most promising methodologies comes from the implementation of nanotechnology. Unlike antibiotics, bacteria are unable to develop resistance to nanoparticles. Many methods for synthesis of various types of nanostructures have been reported. Nevertheless, they are often accompanied by significant drawbacks such as cost, harsh processing conditions, and production of toxic by-products that are a concern for both the environment and society. In this work, an environmentally-friendly and cost-effective approach for synthesis of tellurium nanorods in aqueous media have been developed using aloe vera extract as a unique reducing agent. Nanorods were characterized using Transmission Electron Microscopy and Energy-Dispersive X-Ray Spectroscopy to determine size, morphology and composition. Resulting nanoparticles with a length 100±19 nm and width of 5±2 were produced. Nanoparticles were also characterized and tested for their ability to inhibit bacterial growth. A decay in bacterial growth after 24 hours was achieved for both Staphylococcus aureus and Escherichia coli at tellurium nanoparticle concentrations from 5 to 75 µg/mL. Biocompatibility assays were also performed, and the nanoparticles showed no cytotoxic effects for human dermal fibroblast cells after 48 hours. Anticancer properties were tested as well, and results indicated that the nanoparticles (in concentrations ranging from 5 to 75 µg/mL) were able to delay cancer cell proliferation. Aloe vera extracts afforded synthesis of tellurium nanoparticles in a quick, cost-effective and completely green approach that showed both antimicrobial and anticancer effects with low cytotoxicity for healthy cells.