Theranostics 2018; 8(10):2696-2708. doi:10.7150/thno.23686

Research Paper

A large, switchable optical clearing skull window for cerebrovascular imaging

Chao Zhang1,2, Wei Feng1,2, Yanjie Zhao1,2, Tingting Yu1,2, Pengcheng Li1,2, Tonghui Xu1,2, Qingming Luo1,2, Dan Zhu1,2✉

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, Collaborative Innovation Center for Biomedical Engineering, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China

Abstract

Rationale: Intravital optical imaging is a significant method for investigating cerebrovascular structure and function. However, its imaging contrast and depth are limited by the turbid skull. Tissue optical clearing has a great potential for solving this problem. Our goal was to develop a transparent skull window, without performing a craniotomy, for use in assessing cerebrovascular structure and function.

Methods: Skull optical clearing agents were topically applied to the skulls of mice to create a transparent window within 15 min. The clearing efficacy, repeatability, and safety of the skull window were then investigated.

Results: Imaging through the optical clearing skull window enhanced both the contrast and the depth of intravital imaging. The skull window could be used on 2-8-month-old mice and could be expanded from regional to bi-hemispheric. In addition, the window could be repeatedly established without inducing observable inflammation and metabolic toxicity.

Conclusion: We successfully developed an easy-to-handle, large, switchable, and safe optical clearing skull window. Combined with various optical imaging techniques, cerebrovascular structure and function can be observed through this optical clearing skull window. Thus, it has the potential for use in basic research on the physiopathologic processes of cortical vessels.

Keywords: in vivo skull optical clearing, in vivo optical imaging, laser speckle contrast imaging, hyperspectral imaging, cerebral blood flow (CBF), oxygen saturation (SO2).

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How to cite this article:
Zhang C, Feng W, Zhao Y, Yu T, Li P, Xu T, Luo Q, Zhu D. A large, switchable optical clearing skull window for cerebrovascular imaging. Theranostics 2018; 8(10):2696-2708. doi:10.7150/thno.23686. Available from http://www.thno.org/v08p2696.htm