Unprecedented Sensitivity in a Probe for Monitoring Cathepsin B: Chemiluminescence Microscopy Cell‐Imaging of a Natively Expressed Enzyme

Abstract

Until recently, chemiluminescence cell images could only be obtained using luciferase‐activated probes. Moreover, chemiluminescence microscopy cell‐imaging has not been demonstrated for natively expressed enzymes like cathepsin B. Herein, we describe the design, synthesis, and evaluation of the first chemiluminescence probe for the detection and imaging of cathepsin B. The probe activation mechanism relies on the release of a dioxetane intermediate, which undergoes chemiexcitation to emit green light with high efficiency under physiological conditions. Using the probe, we obtained clear images of cancerous leukemia and colon cells. This is the first demonstration of chemiluminescence cell images obtained by a probe for a natively expressed endogenous enzyme. We anticipate that the concept presented in this study will be broadly used to develop analogous probes for other important proteases relevant to biomolecular processes.

Development of organic semiconducting materials for deep-tissue optical imaging, phototherapy and photoactivation

“…A class of chemiluminescent small molecular probes based on dioxetane have been developed for imaging of different disease biomarkers. [95][96][97][98][99] These small-molecular probes do not require any prior oxidation steps to trigger chemiexcitation because the dioxetane compounds are pre-oxidized in a thermally stable form, which is different from most of other chemiluminescent nanoprobes. [100][101][102] Such chemiluminescence is excited upon removal of the protecting groups (PGs), which results in an electron transfer from a phenolate to the peroxide bond of dioxetane (Fig.…”

Activatable Photodynamic Therapy with Therapeutic Effect Prediction Based on a Self-correction Upconversion Nanoprobe

“…Cancer cell MCF-7 with higher CaB expression , and normal cell NIH 3T3 with suppressed CaB expression , were further incubated with the upconversion nanoprobe for activatable PDT and simultaneous therapeutic effect prediction. The green fluorescence from MUCNPs at 540 nm as internal standard was clearly shown in both cells, indicating efficient endocytosis process of upconversion nanoprobes.…”

Prevent or Cure—The Unprecedented Need for Self‐Reporting Materials

“…[123,125,132] By carefully choosing the phenol substituents (and their position) of Schaapsd ioxetane discovered in 1987, aplethora of CL 1,2-dioxetane derivatives for (bio-)labeling and imaging have been developed, which are also suitable for in vivo applications under physiological conditions. [126,[171][172][173][174][175][176][177] Besides the thermal and chemical activation, the CL of 1,2-dioxetanes can also be triggered by mechanical forces. Theincorporation of bis(adamantyl)1,2-dioxetanes into polymeric materials (e.g.p olyurethane, [178][179][180][181] poly(methyl methacrylate), [182] poly(methyl acrylate), [183,184] )p oly(dimethylsiloxane) [185] )e nabled the facile,r eal-time monitoring of bond breaking events in such materials,s ince mechanical force leads to ab ond scission of the dioxetane moiety into two adamantone-terminated polymer chain visualized by the emission of light, as can be seen in Scheme 3C.C learly,1 ,2dioxetanes represent an important class for the development of versatile,s mart, self-reporting materials since the CL can be easily tailored to the desired stimulus by thorough choice of the respective 1,2-dioxetane derivative.…”