Low-toxicity FePt nanoparticles for the targeted and enhanced diagnosis of breast tumors using few centimeters deep whole-body photoacoustic imaging

Yubin Liu,Pei-Chun Wu,Sen Guo,Pi-Tai Chou,Chuxia Deng,Shang-Wei Chou,Zhen Yuan,Tzu-Ming Liu

doi:10.1016/j.pacs.2020.100179

Yubin Liu, Pei-Chun Wu + Show 6 more

Open Access

https://doi.org/10.1016/j.pacs.2020.100179

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Journal: Photoacoustics	Publication Date: Apr 11, 2020
Citations: 16	License type: cc-by

Affiliation: University of Macau, National Taiwan University

Abstract

A considerable amount of early breast tumors grown at a depth over 2 cm in breast tissues. With high near-infrared absorption of iron-platinum (FePt) nanoparticles, we achieved few centimeters deep photoacoustic (PA) imaging for the diagnosis of breast tumors. The imaging depth can extend over 5 cm in chicken breast tissues at the low laser energy density of 20 mJ/cm2 (≤ ANSI safety limit). After anti-VEGFR conjugation and the tail-vein injection, we validated their targeting on tumor sites by the confocal microscopy and PA imaging. Using a home-made whole-body in vivo PA imaging, we found that the nanoparticles were rapidly cleared away from the site of the tumor and majorly metabolized through the liver. These results validated the clinical potential of the FePt nanoparticles in the low-toxicity PA theragnosis of early breast cancer and showed the capacity of our whole-body PA imaging technique on monitoring the dynamic biodistribution of nanoparticles in the living body.

Highlights

Breast cancer is the second most common type of cancer after lung cancer worldwide, and one in four women in the United States will develop breast cancer during their lifetime
Fourier Transform Infrared (FTIR) spectra of the as-prepared FePt nanoparticles and cysteamine-modified FePt NPs reveal the characteristic bands from the adsorbed ligands, including oleic acid, oleyl amine, and cysteamine, on the surface (Fig. 2b)
In the 488 nm excited fluorescence confocal image of cryosectioned tumor tissues, this contrast of FePt NPs can reveal the targeted distribution of particles in the microenvironment of green fluorescence protein (GFP)-labeled tumor cells. These results demonstrated that the anti-VEGFR conjugated FePt nanoparticles have good targeting ability for breast tumors

Summary

Introduction

Breast cancer is the second most common type of cancer after lung cancer worldwide, and one in four women in the United States will develop breast cancer during their lifetime. While x-ray mammography is the current clinical tool for screening and diagnosis of breast cancer, it has numerous limitations such as the inability of imaging dense breast and the use of ionization radiation. The 5−10 mm spatial resolution of DOT is hard to identify few millimeters sized lumps in breast tissues, which is critical for the early diagnosis of breast tumor [1]. PAI used acoustic detection to overcome the problem of light scattering and offer sub-millimeter resolution of anatomical, functional and molecular imaging at few centimeters imaging depth [2,3,4]. PAI is a very suitable imaging modality for the early detection of breast cancer in vivo. After finding suspected lumps in breast tissues, to increase the sensitivity of detection, the specificity of diagnosis, and the depth of exploration, exogenous contrast agents for nearinfrared PAI are necessary.

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