Physical and chemical mechanisms of tissue optical clearing

Tingting Yu; Jingtan Zhu; Dongyu Li; Dan Zhu

doi:10.1016/j.isci.2021.102178

Physical and chemical mechanisms of tissue optical clearing

iScience. 2021 Feb 12;24(3):102178. doi: 10.1016/j.isci.2021.102178. eCollection 2021 Mar 19.

Authors

Tingting Yu^{1

2}, Jingtan Zhu^{1

2}, Dongyu Li^{1

2}, Dan Zhu^{1

2}

Affiliations

¹ Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China.
² MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China.

Abstract

Advanced optical methods combined with various probes pave the way toward molecular imaging within living cells. However, major challenges are associated with the need to enhance the imaging resolution even further to the subcellular level for the imaging of larger tissues, as well as for in vivo studies. High scattering and absorption of opaque tissues limit the penetration of light into deep tissues and thus the optical imaging depth. Tissue optical clearing technique provides an innovative way to perform deep-tissue imaging. Recently, various optical clearing methods have been developed, which provide tissue clearing based on similar physical principles via different chemical approaches. Here, we introduce the mechanisms of the current clearing methods from fundamental physical and chemical perspectives, including the main physical principle, refractive index matching via various chemical approaches, such as dissociation of collagen, delipidation, decalcification, dehydration, and hyperhydration, to reduce scattering, as well as decolorization to reduce absorption.

Keywords: Biological Sciences; Biological Sciences Tools; Optical Imaging; Research Methodologies.

Publication types

Review