•  
  •  
 
Nano Research

Article Title

pH-sensitive and biodegradable charge-transfer nanocomplex for second near-infrared photoacoustic tumor imaging

Authors

Zhimin Wang, Division of Chemistry and Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
Paul Kumar Upputuri, School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore 637459, Singapore
Xu Zhen, School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore 637459, Singapore
Ruochong Zhang, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
Yuyan Jiang, School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore 637459, Singapore
Xiangzhao Ai, Division of Chemistry and Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
Zhijun Zhang, Division of Chemistry and Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
Ming Hu, Division of Chemistry and Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
Zhenyu Meng, Division of Chemistry and Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
Yunpeng Lu, Division of Chemistry and Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
Yuanjing Zheng, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
Kanyi Pu, School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore 637459, Singapore
Manojit Pramanik, School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore 637459, Singapore
Bengang Xing, Division of Chemistry and Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore

Keywords

charge-transfer nanocomplex, second near-infrared window, photoacoustic imaging, pH-sensitive, biodegradable, tumor acidic microenvironment

Abstract

The emerging technique of photoacoustic imaging, especially in the near infra-red (NIR) window, permits high resolution, deep-penetration, clinically reliable sensing. However, few contrast agents are available that can specifically respond to intricate biological environments, and which are biodegradable and biocompatible. Herein, we introduce a new class of pH-sensitive organic photoacoustic contrast agent that operates in the second NIR window (NIR-II, 960–1,700 nm), which is derived from the self-assembled charge-transfer nanocomplex (CTN) by 3,3’,5,5’-tetramethylbenzidine (TMB) and its dication structure (TMB++). The unique NIR-II-responsive CTN can specifically respond to pH change in the physiological range and allows noninvasive and sensitive visualization of the tumor acidic microenvironment (e.g. at pH 5) in mice with higher signal-to-noise ratio. The CTN is biodegradable under physiological conditions (e.g. pH 7.4), which alleviates the biosafety concern of nanoparticle accumulation in vivo. These results clearly show the potential of the TMB/TMB++-based CTN as a promising pH-activated and biodegradable molecular probe for specific tumor photoacoustic imaging in the NIR-II region.

Graphical Abstract

Publisher

Tsinghua University Press

Share

COinS