Comparison of photoacoustic and fluorescence tomography for the in vivo imaging of ICG-labelled liposomes in the medullary cavity in mice

Abstract

Few reports quantitatively compare the performance of photoacoustic tomography (PAT) versus fluorescence molecular tomography (FMT) in vivo . We compared both modalities for the detection of signals from injected ICG liposomes in the tibial medullary space of 10 BALB/c mice in vivo and ex vivo . Signals significantly correlated between modalities (R² = 0.69) and within each modality in vivo versus ex vivo (PAT: R² = 0.70, FMT: R² = 0.76). Phantom studies showed that signals at 4 mm depth are detected down to 3.3 ng ICG by PAT and 33 ng by FMT, with a nominal spatial resolution below 0.5 mm in PAT and limited to 1 mm in FMT. Our study demonstrates comparable in vivo sensitivity, but superior ex vivo sensitivity and in vivo resolution for our ICG liposomes of the VevoLAZR versus the FMT2500. PAT provides a useful new tool for the high-resolution imaging of bone marrow signals, for example for monitoring drug delivery.

Utilizing Sphingomyelinase Sensitizing Liposomes in Imaging Intestinal Inflammation in Dextran Sulfate Sodium-Induced Murine Colitis

“…As we have previously shown that ICG-loaded SM- liposomes are excellent tracers in photoacoustic (PA) technics [ 35 , 36 , 37 ], we used PA imaging to validate ICG liposome targeting the inflamed tissues in the DSS treated mice. Figure 5 demonstrates a representative image of a colon of mice at day four of DSS treatment with ICG liposomes applied 24 h earlier ( Figure 5 b).…”

Lipid-Iron Nanoparticle with a Cell Stress Release Mechanism Combined with a Local Alternating Magnetic Field Enables Site-Activated Drug Release

“…Surgeons can detect cell stress, potential micrometastases, and tumor borders in the intraoperative environment. Additionally, photoacoustic imaging is a new method that offers in-depth visualization possibilities, up to 10 cm, of fluorescent nano-bio sensors using ICG [ 61 ]. Currently, a robotic DaVinci system equipped with a camera with fluorescence filters suited for ICG imaging is available [ 62 ].…”

Biomedical Photoacoustic Imaging for Molecular Detection and Disease Diagnosis: “Always‐On” and “Turn‐On” Probes

“…Liposomes inhibited ICG aggregation in the bone marrow cavity, and PA tomography imaging was more sensitive, penetrated deeper tissue, and had a greater spatial resolution. [ 60 ] Li et al employed PA tomography imaging to assess the heterogeneity of breast cancer. They developed estrone and progesterone‐modified polyethylene glycol (PEG) wrapping probes with two PA signals (square amine SQ650 (660 nm) and ICG (780 nm)).…”