Photoacoustic Sentinel Lymph Node Imaging with Self-Assembled Copper Neodecanoate Nanoparticles

Abstract

Photoacoustic tomography (PAT) is emerging as a novel, hybrid, and non ionizing imaging modality, because of its satisfactory spatial resolution and high soft tissue contrast. PAT combines the advantages of both optical and ultrasonic imaging methods. It opens up the possibilities for non-invasive staging of breast cancer and may replace sentinel lymph node (SLN) biopsy in clinic in the near future. In this work, we demonstrate for the first time that Copper can be used as a contrast metal for near infrared detection of SLN using PAT. A unique strategy is adopted to encapsulate multiple copies of Cu as organically soluble small molecule complexes within a phospholipids-entrapped nanoparticle. The nanoparticles assumed a size of 80–90nm, which is the optimum hydrodynamic diameter for its distribution throughout the lymphatic systems. These particles provided at least six times higher signal sensitivity in comparison to blood, which is a natural absorber of light. We also demonstrated that high SLN detection sensitivity with PAT can be achieved in rodent model. This work clearly demonstrates for the first time, the potential use of copper as an optical contrast agent.

Intra‐operative ex vivo photoacoustic nodal staging in a rat model using a clinical superparamagnetic iron oxide nanoparticle dispersion

“…Recently, Akers et al visualized the SLN of rats after methylene blue injection and verified their results using SPECT/CT [30]. Pan et al proved that copper nanoparticles can be used to enhance and visualize SLN(s) in vivo using PA imaging [31].…”

Graphene-based contrast agents for photoacoustic and thermoacoustic tomography

“…Contrast-enhanced PAT has been applied in lymph node mapping [7], multiscale imaging of tissue engineering scaffolds [8, 9], and molecular, cellular, and functional imaging [10, 11]. A variety of CAs for PAT have been reported, such as, carbon nanoparticles [7, 12-14], metallic nanoparticles [11] [15-17], and organic dyes [18]. In comparison to PAT, fewer reports have focused on development of CAs for TAT.…”

Carbon nanoparticles as a multimodal thermoacoustic and photoacoustic contrast agent

“…Thus, exogenous contrast agents such as optical dyes, gold nanoparticles, copper nanoparticles, and carbon nanotubes are needed for TAT/PAT in these cases. [3][4][5][6] TAT and PAT have been developed for different applications in rodent models, such as breast cancer imaging, brain structural and functional imaging, blood oxygenation and flow velocity monitoring, and tumor angiogenesis. 1,[7][8] Although a lot of contrast agents are available for TAT and PAT, they have their disadvantages.…”