1064‐nm‐resonant gold nanorods for photoacoustic theranostics within permissible exposure limits

Abstract

Therapeutic and diagnostic methods based on photomechanical effects are attracting much current attention in contexts as oncology, cardiology and vascular surgery, for such applications as photoacoustic imaging or microsurgery. Their underlying mechanism is the generation of ultrasound or cavitation from the interaction of short optical pulses with endogenous dyes or targeted contrast agents. Among the latter, gold nanorods are outstanding candidates, but their use has mainly been reported for photoacoustic imaging and photothermal treatments. Conversely, much less is still known about their value as a precision tool for photomechanical manipulations, such as to impart local damage with high spatial resolution through the expansion and collapse of microbubbles. Here, we address the feasibility of gold nanorods exhibiting a distribution of surface plasmon resonances between about 900 to above 1100 nm as a contrast agent for photoacoustic theranostics. After testing their cytotoxicity and cellular uptake, we discuss their photostability and use to mediate cavitation and the photomechanical destruction of targeted cells. We find that the choice of a plasmonic band peaking around 1064 nm is key to enhance the translational potential of this approach. With respect to the standard alternative of 800 nm, at 1064 nm, relevant regulations on optical exposure are less restrictive and the photonic technology is more mature.

Surfactant‐Stripped Micelles for NIR‐II Photoacoustic Imaging through 12 cm of Breast Tissue and Whole Human Breasts

“…[14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] For PAI, the use of contrast agents with absorption at 1064 nm matches the output of Nd:YAG pulse lasers, has a higher American National Standards Institute (ANSI) safety limit for laser pulse power, and reduces scattering for deep tissue imaging. Many contrast agents have been explored for PAI at 1064 nm including copper sulfide [33] , semi-conducting polymers [34][35][36][37] , gold nanorods [38,39] and others.…”

Improving Plasmonic Photothermal Therapy of Lung Cancer Cells with Anti-EGFR Targeted Gold Nanorods

“…Zharov et al (2005) concluded that pulsed lasers were more effective at inducing cell death when AuNRs formed nanoclusters on the cell membrane, and this agrees with our findings. Highly localised bubble formation due to the presence of nanoparticles can have other benefits for both therapeutic and imaging applications [ 20 , 21 ].…”

Optically activated and interrogated plasmonic hydrogels for applications in wound healing

“…Gold nanorods were synthesized according to our variant of the protocol developed by Vigderman and Zubarev [71,72]. Thereafter, cetrimonium-capped particles were coated with a Ag shell according to the protocol reported in References [73,74].…”