In situ-based green synthesis of selenium and tellurium nanoparticles as biomedical agents

Abstract

Antimicrobial resistance to antibiotics and cancer are two of the main concerns that the healthcare system is facing nowadays. Nanotechnology, understood as the science of materials when they reach the limit of 100 nm size, was developed as a powerful technique whose application to medicine has supposed a considerable impact on society. However, the development of nanomaterials brought some environmental concerns related to the production of toxic by-products and biocompatibility issues once the nanostructures were contacted with biological tissue. Therefore, new alternatives have been developed, with Green Chemistry as one of the most promising ones. From all the green chemical methodologies, plant-based production of nanomaterials is among the most relevant ones, since they are easy and straightforward, cost-effective and environmentally-friendly. In this thesis, chalcogen nanoparticles -both selenium (Se) and tellurium (Te)- were prepared using a simple green methodology using pepper, coffee and tea extracts as unique reducing and capping agents, triggering the production of different nanoparticles. After characterization, the structures were used for their biomedical applications as antibacterial and anticancer agents, remaining biocompatible over a wide range of concentrations. Therefore, a novel and environmentally-friendly production of selenium and tellurium nanoparticles have been proposed employing natural dietary compounds as reducing agents, overcoming the main limitations of traditional physicochemical approaches.