In‐vivo two‐photon visualization and quantitative detection of redox state of cancer

Abstract

Glutathione (GSH), the most common and abundant antioxidant in the body, is particularly concentrated in cancer cells (2–10 mM). This concentration is approximately 1000 times that of normal cells, making GSH a specific tumor marker. Overexpression of GSH is critical for mapping the redox state of cancer cells. However, there are few probes and detection methods responsive to GSH that can quantitatively visualize GSH in vivo in two‐photon excitation fluorescence (TPEF) imaging mode. The experimental results show that TPEF‐GSH could not only target GSH in tumors, but also establish the quantitative relationship between TPEF signal and GSH concentration. We explored the optimal two‐photon excitation wavelength of TPEF‐GSH, the optimal cell incubation duration with TPEF‐GSH, the best imaging time point for GSH in cells, and the quantitative relationship between the TPEF signal and the changes in GSH concentrations. In zebrafish embryo and zebrafish experiments, the ratiometric value of TPEF‐GSH increased with the decrease of GSH concentration. Microinjection and co‐incubation were used to verify whether the ratiometric value could quantify endogenous GSH in tumor‐bearing zebrafish, and the obtained GSH levels were 4.66 mM and 5.16 mM, respectively. The ratio TPEF probe could accurately visualize and quantify GSH in vivo, reflecting the redox status of the tumor. The design of the ratiometric molecular probe provides a reliable strategy for the development of TPEF nanoprobe in vivo. In this article, a new GSH sensitive molecular probe, TPEF‐GSH, has been developed with good specificity and sensitivity. TPEF‐GSH was successfully used to image cancer cells in vitro and tumor‐bearing zebrafish in vivo, and to further detect GSH levels.

Scattering/Fluorescence Dual-Mode Imaging in MnO2-Coated Silicon Nanospheres for Cancer Cell Detection

“…In Figure j, the PL intensity in HEK293 cells is larger than that outside a cell. A possible explanation for the slight PL recovery in HEK293 cells is the presence of small amounts of GSH and H 2 O 2 in the normal cells. − Note that the large distribution of the PL intensity in Figure j comes mainly from that of the NS core diameter; i.e., a larger NP has a larger surface area and thus has larger amounts of dye molecules on the surface, as can be seen in Figure b. Similar Si NS core-size dependence of the PL intensity is obtained in cells (Figure S8 in the Supporting Information).…”

Molecular imaging of tumour‐associated pathological biomarkers with smart nanoprobe: From “Seeing” to “Measuring”

“…With this ratiometric probe, the endogenous GSH levels of tumours in zebrafish were determined as 4.66 and 5.16 mm through injection and incubation administration routes, respectively, which is in line with the traditional cognition of GSH concentration in solid tumours (2-10 mm). [26] In addition to the tumour diagnosis and prognosis evaluation, the ratiometric optical quantitative imaging was also be employed to early evaluate the effectiveness of tumour immunotherapy. As known, the therapeutic efficacy of adoptive cellular immunotherapy is closely associated with the survival rate and durability of transplanted immune cells.…”

“…Quantitative tumour hypoxia imaging in vivo [25] TPEF-GSH Ratiometric OI GSH detection (3.125-9.375 mm) in vivo Quantification and visualization of GSH in pretreated living embryos. [26] DCNP/IR786s Ratiometric NIR-II OI NK cell viability (0-100%) in vitro Tracking of NK cell viability in vivo [28] MnMoOx-PEG PAI/MRI Generating responsive signals to GSH (0-20 mm, down to 0.5 mm) in vitro GSH detection of tumour in vivo [35] C-HSA-BPOx-IR825 Ratiometric PAI/OI Generating responsive signals to pH (4-8) in vitro pH responsive tumour imaging [37] F3-SNARF-PAA Ratiometric PAI Generating response signals to pH (5.8-7.8) in vitro pH responsive tumour imaging [38] QSY21-GPLGVRGY-Cy5.5 OI/Ratiometric PAI MMP-2 detection (0-160 ng mL −1 , down to 0.52 ng mL −1 ) in vitro Quantitative imaging of MMP-2 in tumour in vivo [39] AcDEVD-Cy-RGD NIR OI/ Ratiometric PAI Caspase-3 detection (0-500 ng mL −1 , down to 3.4 ng mL −1 ) in vitro…”

“…With this ratiometric probe, the endogenous GSH levels of tumours in zebrafish were determined as 4.66 and 5.16 m m through injection and incubation administration routes, respectively, which is in line with the traditional cognition of GSH concentration in solid tumours (2–10 m m ). [ 26 ]…”

Review of optical methods for noninvasive imaging of skin fibroblasts—From in vitro to ex vivo and in vivo visualization

“…It is also worth emphasizing the importance of visualizing virus-infected and cancerous fibroblasts, because studying changes in the morphology, behavior and gene expression of fibroblasts will provide a better understanding of how viruses and cancer cells interact with host cells and manipulate them for their own benefit [36][37][38]. This information is important for the development of new methods for the diagnosis and treatment of viral infections and cancer [39,40].…”