Plasmonic nanobubbles for cancer theranostics

Abstract

Biomedical functions of plasmonic nanoparticles are usually determined by physical properties which are preset during their chemical synthesis. These properties are assumed to stay constant during continuous or pulsed optical excitation of plasmonic nanoparticles. We show that nonstationary excitation with short laser pulse creates entirely new transient photothermal and spectral properties of plasmonic nanoparticles that do not fit into the above stationary paradigm. Our novel nonstationary approach allowed, for example, to shift the spectral peak of standard gold colloids from visible to the near-infrared region, to narrow its width from hundreds to 1-2 nm, and to increase the photothermal efficacy. Replacing chemical engineering of sophisticated nanoparticles with the dynamic tuning of transient properties of standard and clinically proved nanoparticles opens principally new opportunities for nanomedicine including diagnosis, therapy, and theranostics. Furthermore, a nonstationary mechanism allowed to replace the photothermal therapy that cannot provide single cell selectivity and suffers from high optical and nanoparticle doses and their nonspecific uptake, by the cell-specific mechanical treatment that can rapidly and selectively destroy only pathological cells, deliver drugs and genetic cargo and unite diagnosis and treatment in one rapid theranostic procedure.