Reconsidering azobenzene as a component of small-molecule hypoxia-mediated cancer drugs: A theranostic case study

Azo‐Based Fluorogenic Probes for Biosensing and Bioimaging: Recent Advances and Upcoming Challenges

“…The first practical example of this dual imaging/therapy strategy was recently published by Verwilst et al. and concerned the design and construction of a theranostic drug‐delivery system (DDS) for cancer therapy (Figure b) . It was based on an AB scaffold that acted as both a fluorescence quencher (i.e., nonfluorescent azo‐RhoB hybrid) and deactivator of an alkylating anticancer drug (i.e., nitrogen mustard N , N ‐bis(2‐chloroethyl)‐ para ‐phenylenediamine), and it also contained a TPP group that combined excellent targeting of the hyperpolarized mitochondria of cancer cells in solid tumors with a convenient means for evading drug resistance.…”

“… a) Principle of small conjugate‐based theranostic agents activated through bioreduction of the azo bridge. b) Structure of a hypoxia‐activated prodrug recently reported by Verwilst et al . TPP=triphenylphosphonium.…”

“…The first practical example of this dual imaging/therapy strategyw as recently published by Verwilst et al and concerned the design andc onstruction of at heranostic drug-delivery system (DDS) for cancert herapy (Figure 25 b). [101] It was based on an AB scaffold that acted as both af luorescence quencher (i.e.,n onfluorescent azo-RhoB hybrid) andd eactivator of an alkylating anticancer drug (i.e.,n itrogen mustard N,Nbis(2-chloroethyl)-para-phenylenediamine), and it also contained aT PP group that combined excellent targeting of the hyperpolarizedm itochondriao fc ancer cells in solid tumors with ac onvenient means for evading drug resistance. As claimedb yt he authors and supported by preliminaryi nv ivo therapeutic experiments, this bioreductively activated theranostic DDS could result in the selectivee radication of hypoxic regionsw ithin solid tumors, providing better treatment options for this challenging fraction of cells within solid tumors.…”

A Noncovalent Fluorescence Turn‐on Strategy for Hypoxia Imaging

“…The disappearance of the azo absorption indicates ac omplete reduction reaction i.e.a ll four azo groups of CAC4A were reduced (Figure 3a). [29] Ther eduction product of CAC4A was further examined by using mass spectrometry analysis.T he mass spectrum of CAC4A shows peaks at 509 and 1017, corresponding to [M+ +2H] 2+ and [M+ +H] + ,r espectively (Supporting Information, Figure S10a). R 2 > 0.993), giving the rate constant of 0.905 min À1 (Supporting Information , Figure S9).…”

“…Theh alf-life was calculated as 46 s, which is at the same level of similar compounds containing as ingle azo group. [29] Ther eduction product of CAC4A was further examined by using mass spectrometry analysis.T he mass spectrum of CAC4A shows peaks at 509 and 1017, corresponding to [M+ +2H] 2+ and [M+ +H] + ,r espectively (Supporting Information, Figure S10a). Aminocalix [4]arene was found Figure 3.…”