Self-Enhanced Carbonized Polymer Dots for Selective Visualization of Lysosomes and Real-Time Apoptosis Monitoring

Xiaohuan Zhao; Jing Li; Dongning Liu; Mingxi Yang; Wenjing Wang; Shoujun Zhu; Bai Yang

doi:10.1016/j.isci.2020.100982

Self-Enhanced Carbonized Polymer Dots for Selective Visualization of Lysosomes and Real-Time Apoptosis Monitoring

iScience. 2020 Apr 24;23(4):100982. doi: 10.1016/j.isci.2020.100982. Epub 2020 Mar 13.

Authors

Xiaohuan Zhao¹, Jing Li², Dongning Liu³, Mingxi Yang¹, Wenjing Wang¹, Shoujun Zhu⁴, Bai Yang⁵

Affiliations

¹ State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin 130012, P. R. China.
² The Scientific Research Center, China-Japan Union Hospital, Jilin University, Changchun, Jilin 130033, P. R. China.
³ Department of Periodontology, Stomatology Hospital, Jilin University, Changchun, Jilin 130021, P. R. China.
⁴ State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin 130012, P. R. China; Key Laboratory of Organ Regeneration & Transplantation of the Ministry of Education, The First Hospital of Jilin University, Changchun, Jilin 130061, P.R. China.
⁵ State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin 130012, P. R. China. Electronic address: byangchem@jlu.edu.cn.

Abstract

Protons are highly related to cell viability during physiological and pathological processes. Developing new probes to monitor the pH variation could be extremely helpful to understand the viability of cells and the cell death study. Carbonized polymer dots (CPDs) are superior biocompatible and have been widely applied in bioimaging field. Herein, a new type of extreme-pH suitable CPDs was prepared from citric acid and o-phenylenediamine (CA/oPD-CPDs). Due to the co-existence of hydrophilic and hydrophobic groups, CA/oPD-CPDs tend to aggregate in neutral condition with a dramatic decrease of fluorescence, but disperse well in both acidic and alkaline conditions with brighter emission. This specialty enables them to selectively illuminate lysosomes in cells. Moreover, CA/oPD-CPDs in the cytoplasm could serve as a sustained probe to record intracellular pH variation during apoptosis. Furthermore, CA/oPD-CPDs present a continuous fluorescence increase upon 2-h laser irradiation in living cells, underscoring this imaging system for long-term biological recording.

Keywords: Biotechnology; Optical Materials; Organic Chemistry.