(432b) Multifunctional Hybrid Plasmonic-Superparamagnetic Nanoparticles for Photothermal Cancer Cell Killing
Plasmonic nanoparticles play an important role in biomedical applications today as they can serve as superior optically-stable bioimaging agents, be employed in biosensor devices for the early diagnosis of diseases, and exhibit promising results for their employment in vivo as therapeutic agents. For several bioapplications, however, nanoparticles that express more than one functionality are often advantageous. This has led to the synthesis of multifunctional plasmonic nanoparticles that combine the attractive plasmonic properties with other functionalities like magnetism, photoluminescence, dispersibility in aqueous solutions and resistance to degradation. Furthermore, tumor ablation by thermal energy via the irradiation of plasmonic nano-particles is a relatively new oncology treatment. Here, hybrid plasmonic-superparamagnetic nanoaggregates (50–100 nm in diameter) consisting of SiO2-coated Fe2O3 and Au (≈30 nm) nanoparticles were fabricated using scalable flame aerosol technology. By finely tuning the Au interparticle distance using the SiO2 film thickness (or content) the plasmonic coupling of Au nanoparticles can be finely controlled bringing their optical absorption to the near-IR that is most important for human tissue transmittance. The SiO2 shell facilitates also dispersion and prevents the reshaping or coalescence of Au particles during laser irradiation, thereby allowing their use in multiple treatments. Their effectiveness as photo-thermal agents is demonstrated by killing human breast cancer cells with a short, four minute near-IR laser irradiation (785 nm) at low flux (4.9 W cm-2).
 G.A. Sotiriou, T. Sannomiya, A. Teleki, F. Krumeich, J. Vörös, S.E. Pratsinis, “Non-toxic, Dry-coated Nanosilver for Plasmonic Biosensors”, Adv. Funct. Mater. 20, 4250-4257 (2010).
 G.A. Sotiriou, A. Hirt, P.-Y. Lozach, A. Teleki, F. Krumeich, S.E. Pratsinis, “Hybrid Silica-coated, Janus-like Plasmonic-Magnetic Nanoparticles”, Chem. Mater. 23, 1985-1992 (2011).
 G.A. Sotiriou, F. Starsich, A. Dasargyri, M.C. Wurnig, F. Krumeich, A. Boss, J-C. Leroux, S.E. Pratsinis. “Photothermal Killing of Cancer Cells by the Controlled Plasmonic Coupling of Silica-coated Au/Fe2O3 Nanoaggregates”, Adv. Funct. Mater. in press, DOI: 10.1002/adfm.201303416 (2014).