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USE OF SILICA-COATED SILVER NANOPARTICLES AS CYTOTOXIC AGENTS
WO10066938
The selective and efficient induction of cell death is the most promising biomedical applications of nanoparticles (NPs). Silver, a metal generally used for the preparation of NPs, has been used for decades as a bactericidal agent and its antibiotic effects have been successfully tested. The University of Valencia has developed a new type of silver nanoparticles coated with a silica nanocoating, able to exert selective killing of bacteria by irradiating at their surface plasmon frequency. The nanoparticles bind to the surface of the bacteria without interfering with their growth, as the toxic silver core is covered with silica. Exposing the NPs to radiation in the absorption band of the silver core triggers effective and selective killing of the bacteria.
Applications: The main application of the technology is in biomedicine, in phototherapy methods for the treatment of infectious illnesses through the inducement of cell death. Advantages: The most remarkable advantages provided by this technology are: • Photoswitchable toxicity, allowing the inducement of cell death upon proper irradiation at a specific length wave. • Low power of radiation needed to induce cytotoxicity, so cell death may not be due to thermal effects. • High level of interaction with biological materials, like bacterial cells, due to the large surface area and high reactivity of the nanoparticles.