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Heparan sulfate (HS) plays important roles in many biological processes. The inherent complexity of naturally existing HS has severely hindered the thorough understanding of their structure‐activity relationship. To facilitate biological studies, a new strategy has been developed to synthesize a HS‐like pseudo‐hexasaccharide library, where HS disaccharides were linked in a “head‐to‐tail” fashion from the reducing end of a disaccharide module to the non‐reducing end of a neighboring module. Combinatorial syntheses of 27 HS‐like pseudo‐hexasaccharides were achieved. This new class of compounds bound with fibroblast growth factor 2 (FGF‐2) with similar structure‐activity trends as HS oligosaccharides bearing native glycosyl linkages. The ease of synthesis and the ability to mirror natural HS activity trends suggest that the new head‐to‐tail linked pseudo‐oligosaccharides could be an exciting tool to facilitate the understanding of HS biology.

Heparan sulfate (HS) plays important roles in many biological processes. The inherent complexity of naturally existing HS has severely hindered the thorough understanding of their structure‐activity relationship. To facilitate biological studies, a new strategy has been developed to synthesize a HS‐like pseudo‐hexasaccharide library, where HS disaccharides were linked in a “head‐to‐tail” fashion from the reducing end of a disaccharide module to the non‐reducing end of a neighboring module. Combinatorial syntheses of 27 HS‐like pseudo‐hexasaccharides were achieved. This new class of compounds bound with fibroblast growth factor 2 (FGF‐2) with similar structure‐activity trends as HS oligosaccharides bearing native glycosyl linkages. The ease of synthesis and the ability to mirror natural HS activity trends suggest that the new head‐to‐tail linked pseudo‐oligosaccharides could be an exciting tool to facilitate the understanding of HS biology.

In a conjugated polymer‐based single‐particle heterojunction, stochastic fluctuations of the photogenerated hole population lead to spontaneous fluorescence switching. We found that 405 nm irradiation can induce charge recombination and activate the single‐particle emission. Based on these phenomena, we developed a novel class of semiconducting polymer dots that can operate in two superresolution imaging modes. The spontaneous switching mode offers efficient imaging of large areas, with <10 nm localization precision, while the photoactivation/deactivation mode offers slower imaging, with further improved localization precision (ca. 1 nm), showing advantages in resolving small structures that require high spatial resolution. Superresolution imaging of microtubules and clathrin‐coated pits was demonstrated, under both modes. The excellent localization precision and versatile imaging options provided by these nanoparticles offer clear advantages for imaging of various biological systems.

In a conjugated polymer‐based single‐particle heterojunction, stochastic fluctuations of the photogenerated hole population lead to spontaneous fluorescence switching. We found that 405 nm irradiation can induce charge recombination and activate the single‐particle emission. Based on these phenomena, we developed a novel class of semiconducting polymer dots that can operate in two superresolution imaging modes. The spontaneous switching mode offers efficient imaging of large areas, with <10 nm localization precision, while the photoactivation/deactivation mode offers slower imaging, with further improved localization precision (ca. 1 nm), showing advantages in resolving small structures that require high spatial resolution. Superresolution imaging of microtubules and clathrin‐coated pits was demonstrated, under both modes. The excellent localization precision and versatile imaging options provided by these nanoparticles offer clear advantages for imaging of various biological systems.