Dataset Information

Rapid Macrocycle Threading by a Fluorescent Dye-Polymer Conjugate in Water with Nanomolar Affinity.

ABSTRACT: A macrocyclic tetralactam host is threaded by a highly fluorescent squaraine dye that is flanked by two polyethylene glycol (PEG) chains with nanomolar dissociation constants in water. Furthermore, the rates of bimolecular association are very fast with k(on) ? 10(6)-10(7) M(-1) s(-1). The association is effective under cell culture conditions and produces large changes in dye optical properties including turn-on near-infrared fluorescence that can be imaged using cell microscopy. Association constants in water are ?1000 times higher than those in organic solvents and strongly enthalpically favored at 27 °C. The threading rate is hardly affected by the length of the PEG chains that flank the squaraine dye. For example, macrocycle threading by a dye conjugate with two appended PEG2000 chains is only three times slower than threading by a conjugate with triethylene glycol chains that are 20 times shorter. The results are a promising advance toward synthetic mimics of streptavidin/biotin.

SUBMITTER: Peck EM

PROVIDER: S-EPMC4643739 | biostudies-literature | 2015 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Rapid Macrocycle Threading by a Fluorescent Dye-Polymer Conjugate in Water with Nanomolar Affinity.

Peck Evan M EM Liu Wenqi W Spence Graeme T GT Shaw Scott K SK Davis Anthony P AP Destecroix Harry H Smith Bradley D BD

Journal of the American Chemical Society 20150629 27

A macrocyclic tetralactam host is threaded by a highly fluorescent squaraine dye that is flanked by two polyethylene glycol (PEG) chains with nanomolar dissociation constants in water. Furthermore, the rates of bimolecular association are very fast with k(on) ≈ 10(6)-10(7) M(-1) s(-1). The association is effective under cell culture conditions and produces large changes in dye optical properties including turn-on near-infrared fluorescence that can be imaged using cell microscopy. Association co ...[more]

PMID: 26106948

Similar Datasets

Project description:Tumor hypoxia is associated with the rapid proliferation and growth of malignant tumors, and the ability to detect tumor hypoxia is important for predicting tumor response to anti-cancer treatments. We have developed a class of dye-conjugates that are related to indocyanine green (ICG, ) to target tumor hypoxia, based on in vivo infrared fluorescence imaging using nitroimidazole moieties linked to indocyanine fluorescent dyes. We previously reported that linking 2-nitroimidazole to an indocyanine dicarboxylic acid dye derivative () using an ethanolamine linker (ethanolamine-2-nitroimidazole-ICG, ), led to a dye-conjugate that gave promising results for targeting cancer hypoxia in vivo. Structural modification of the dye conjugate replaced the ethanolamine unit with a piperazineacetyl unit and led a second generation dye conjugate, piperzine-2-nitroimidazole-ICG (). This second generation dye-conjugate showed improved targeting of tumor hypoxia when compared with . Based on the hypothesis that molecules with more planar and rigid structures have a higher fluorescence yield, as they could release less absorbed energy through molecular vibration or collision, we have developed a new 2-nitroimidazole ICG conjugate, , with two carbon atoms less in the polyene linker. Dye-conjugate was prepared from our new dye (), and coupled to 2-nitroimidazole using a piperazine linker to produce this third-generation dye-conjugate. Spectral measurements showed that the absorption/emission wavelengths of 657/670 were shifted ?100 nm from the second-generation hypoxia dye of 755/780 nm. Its fluorescence quantum yield was measured to be 0.467, which is about 5 times higher than that of (0.083). In vivo experiments were conducted with balb/c mice and showed more than twice the average in vivo fluorescence intensity in the tumor beyond two hours post retro-orbital injection as compared with . These initial results suggest that may significantly improve in vivo tumor hypoxia targeting.

Dataset Information

Rapid Macrocycle Threading by a Fluorescent Dye-Polymer Conjugate in Water with Nanomolar Affinity.

Publications

Rapid Macrocycle Threading by a Fluorescent Dye-Polymer Conjugate in Water with Nanomolar Affinity.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets