Multifunctionalized gold nanoparticles for controlled drug-release by non-linear excitation

V. Voliani, F. Ricci, G. Signore, R. Nifosì, S. Luin, F. Beltram
Center for nanotechnology innovation @NST, Istituto italiano di tecnologia and Scuola normale superiore, IT

Keywords: multiphoton, gold nanoparticles, release, peptide coating, photochemistry

Summary:

Photocleavable molecules have a great potential and interest as diagnostic and therapeutic tools, but several unsolved problems hinder their widespread clinical use. One of these open issues is the radiation frequency required for photocleaving. Usually it belongs to the UV-violet region of the spectrum and is consequently toxic for living cells and marred by low penetration depth in tissues. Here we present the first modular nanosystem designed for the photorelease of molecular payloads by irradiation with yellow-green light. Standard click-chemistry is used to covalently conjugate the molecular payload to peptide-coated 30-nm gold nanoparticles via a 1,2,3-triazole-ring photo-cleavable linker. We show that this system can effectively release its payload by low-intensity irradiation with 561-nm wavelength cw laser light. Photocleaving is made possible by the field enhancement occurring in the proximity of metallic nanostructures owing to the stimulation of localized surface plasmon resonance. The ability to perform the controlled photocleavage of UV-labile molecules by means of visible or NIR radiations opens exciting perspectives in nanomedicine. In this article we present the behavior of these nanosystems and demonstrate the controlled photorelease of dyes in living cells.