Photoacoustic microscopy for evaluating combretastatin A4 phosphate induced vascular disruption in orthotopic glioma

Abstract Detection of sentinel lymph nodes (SLNs) is critical to guide the treatment of breast cancer. However, distinguishing metastatic SLNs from normal and inflamed lymph nodes (LNs) during surgical resection remains a challenge. Here, we report a CD44 and scavenger receptor class B1 dual-targeting hyaluronic acid nanoparticle (5K-HA-HPPS) loaded with the near-infra-red fluorescent dye DiR-BOA for SLN imaging in breast cancer. The small sized (~40 nm) self-assembled 5K-HA-HPPSs accumulated rapidly in the SLNs after intradermal injection. Compared with normal popliteal LNs (N-LN), there were ~3.2-fold and ~2.4-fold increases in fluorescence intensity in tumour metastatic SLNs (T-MLN) and inflamed LNs (Inf-LN), respectively, 6 h after nanoparticle inoculation. More importantly, photoacoustic microscopy (PAM) of 5K-HA-HPPS showed a significantly distinct distribution in T-MLN compared with N-LN and Inf-LN. Signals were mainly distributed at the centre of T-MLN but at the periphery of N-LN and Inf-LN. The ratio of PA intensity (R) at the centre of the LNs compared with that at the periphery was 5.93 ± 0.75 for T-MLNs of the 5K-HA-HPPS group, which was much higher than that for the Inf-LNs (R = 0.2 ± 0.07) and N-LNs (R = 0.45 ± 0.09). These results suggest that 5K-HA-HPPS injection combined with PAM provides a powerful tool for distinguishing metastatic SLNs from pLNs and inflamed LNs, thus guiding the removal of SLNs during breast cancer surgery.

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High-resolution in vivo imaging of rhesus cerebral cortex with ultrafast portable photoacoustic microscopy

NeuroImage ◽

10.1016/j.neuroimage.2021.118260 ◽

2021 ◽

pp. 118260

Author(s):

Wei Qin ◽

Qi Gan ◽

Lei Yang ◽

Yongchao Wang ◽

Weizhi Qi ◽

...

Keyword(s):

Cerebral Cortex ◽

High Resolution ◽

In Vivo Imaging ◽

Photoacoustic Microscopy

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Recovery of photoacoustic images based on accurate ultrasound positioning

Visual Computing for Industry Biomedicine and Art ◽

10.1186/s42492-021-00072-2 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Yinhao Pan ◽

Ningbo Chen ◽

Liangjian Liu ◽

Chengbo Liu ◽

Zhiqiang Xu ◽

...

Keyword(s):

Biological Tissue ◽

Large Field ◽

Photoacoustic Microscopy ◽

Label Free ◽

Imaging Data ◽

Motor Speed ◽

Image Correction ◽

Microscopy Imaging ◽

Scanning Method

AbstractPhotoacoustic microscopy is an in vivo imaging technology based on the photoacoustic effect. It is widely used in various biomedical studies because it can provide high-resolution images while being label-free, safe, and harmless to biological tissue. Polygon-scanning is an effective scanning method in photoacoustic microscopy that can realize fast imaging of biological tissue with a large field of view. However, in polygon-scanning, fluctuations of the rotating motor speed and the geometric error of the rotating mirror cause image distortions, which seriously affect the photoacoustic-microscopy imaging quality. To improve the image quality of photoacoustic microscopy using polygon-scanning, an image correction method is proposed based on accurate ultrasound positioning. In this method, the photoacoustic and ultrasound imaging data of the sample are simultaneously obtained, and the angle information of each mirror used in the polygon-scanning is extracted from the ultrasonic data to correct the photoacoustic images. Experimental results show that the proposed method can significantly reduce image distortions in photoacoustic microscopy, with the image dislocation offset decreasing from 24.774 to 10.365 μm.

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