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Activatable Polymeric Nanoprobe for Near‐Infrared Fluorescence and Photoacoustic Imaging of T Lymphocytes
Author(s) -
Zhang Yan,
He Shasha,
Chen Wan,
Liu Yinghua,
Zhang Xuefei,
Miao Qingqing,
Pu Kanyi
Publication year - 2021
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202015116
Subject(s) - nanoprobe , granzyme b , cyanine , photoacoustic imaging in biomedicine , cytotoxic t cell , fluorescence , chemistry , molecular imaging , immune system , fluorescence lifetime imaging microscopy , immunotherapy , in vivo , biophysics , materials science , cancer research , nanotechnology , medicine , in vitro , biochemistry , immunology , biology , physics , microbiology and biotechnology , quantum mechanics , nanoparticle , optics
Development of real‐time non‐invasive imaging probes to assess infiltration and activation of cytotoxic T cells (CTLs) is critical to predict the efficacy of cancer immunotherapy, which however remains challenging. Reported here is an activatable semiconducting polymer nanoprobe (SPNP) for near‐infrared fluorescence (NIRF) and photoacoustic (PA) imaging of a biomarker (granzyme B) associated with activation of CTLs. SPNP comprises a semiconducting polymer (SP) conjugated with a granzyme B cleavable and dye‐labeled peptide as the side chain, both of which emit NIRF and PA signals. After systemic administration, SPNP passively targets the tumor and in situ reacts with granzyme B to release the dye‐labeled peptide, leading to decreased NIRF and PA signals from the dye but unchanged signals from the polymer. Such ratiometric NIRF and PA signals of SPNP correlate well with the expression level of granzyme B and intratumoral population of CTLs. Thus, this study not only presents the first PA probes for in vivo imaging of immune activation but also provides a molecular design strategy that can be generalized for molecular imaging of other immune‐related biomarkers.