Organic Semiconducting Polymer Nanoparticles for Photoacoustic Labeling and Tracking of Stem Cells in the Second Near-Infrared Window was written by Yin, Chao;Wen, Guohua;Liu, Chao;Yang, Boguang;Lin, Sien;Huang, Jiawei;Zhao, Pengchao;Wong, Siu Hong Dexter;Zhang, Kunyu;Chen, Xiaoyu;Li, Gang;Jiang, Xiaohua;Huang, Jianping;Pu, Kanyi;Wang, Lidai;Bian, Liming. And the article was included in ACS Nano in 2018.Electric Literature of C5H6ClN This article mentions the following:
Photoacoustic (PA) imaging and tracking of stem cells plays an important role in the real-time assessment of cell-based therapies. Nevertheless, the limitations of conventional inorganic PA contrast agents and the narrow range of the excitation wavelength in the first near-IR (NIR-I) window hamper the applications of PA imaging in living subjects. Herein, we report the design and synthesis of a second near-IR (NIR-II) absorptive organic semiconducting polymer (OSP)-based nanoprobe (OSPN+) for PA imaging and tracking of stem cells. Comparison studies in biol. tissue show that NIR-II light excited PA imaging of the OSPN+ has significantly higher signal-to-noise ratio than NIR-I light excited PA imaging, thereby demonstrating the superiority of the OSPN+ for deep tissue imaging. With good biocompatibility, appropriate size, and optimized surface property, the OSPN+ shows enhanced cellular uptake for highly efficient PA labeling of stem cells. In vivo investigations reveal significant NIR-II PA contrast enhancement of the transplanted OSPN+-labeled human mesenchymal stem cells by 40.6- and 21.7-fold in s.c. and brain imaging, resp., compared with unlabeled cases. Our work demonstrates a class of OSP-based nanomaterials for NIR-II PA stem cell imaging to facilitate a better understanding and evaluation of stem cell-based therapies. In the experiment, the researchers used many compounds, for example, Pyridinehydrochloride (cas: 628-13-7Electric Literature of C5H6ClN).
Pyridinehydrochloride (cas: 628-13-7) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). Several pyridine derivatives play important roles in biological systems. While its biosynthesis is not fully understood, nicotinic acid (vitamin B3) occurs in some bacteria, fungi, and mammals.Electric Literature of C5H6ClN