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The design and synthesis of the near‐infrared (NIR)‐II emissive conjugated oligoelectrolyte COE‐BBT are reported. COE‐BBT has a solubility in aqueous media greater than 50 mg mL−1, low toxicity, and a propensity to intercalate lipid bilayers, wherein it exhibits a higher emission quantum yield relative to aqueous media. Addition of COE‐BBT to cells provides two emission channels, at ≈500 and ≈1020 nm, depending on the excitation wavelength, which facilitates in vitro confocal microscopy and in vivo animal imaging. The NIR‐II emission of COE‐BBT is used to track intracranial and subcutaneous tumor progression in mice. Of relevance is that the total NIR‐II intensity increases over time. This phenomenon is attributed to a progressive attenuation of a COE‐BBT self‐quenching effect within the cells due to the expected dye dilution per cell as the tumor proliferates.

We developed a series of transmembrane conjugated oligoelectrolytes (COEs) with tunable optical emissions from the UV to the near IR to address the false-positive problem when detecting nanometer-sized extracellular vesicles (EVs) by flow cytometry. The amphiphilic molecular framework of COEs is defined by a linear conjugated structure and cationic charged groups at each terminal site. Consequently, COEs have excellent water solubility and the absence of nanoaggregates at concentrations up to 50 μM, and unbound COE dyes can be readily removed through ultrafiltration. These properties enable unambiguous and simple detection of COE-labeled small EVs using flow cytometry with negligible background signals. We also demonstrated the time-lapsed tracking of small EV uptake into mammalian cells and the endogenous small EV labeling using COEs. Briefly, COEs provide a class of membrane-targeting dyes that behave as biomimetics of the lipid bilayer and a general and practical labeling strategy for nanosized EVs.

Background/aimsTo identify factors that influence the diagnostic performance of circumpapillary retinal nerve fibre layer (RNFL) thickness measurements in the detection of primary open-angle glaucoma (POAG).Methods1592 eyes from 1076 healthy controls and 758 eyes from 502 patients with POAG underwent optical coherence tomography (OCT) imaging to assess RNFL parameters. Visual field (VF) mean deviation (MD) from standard automated perimetry was used to indicate severity in subjects with glaucoma.ResultsRNFL thickness significantly decreased with age (ρ=−0.10 to −0.16, p<0.001) and increased with spherical equivalent (SE) refractive error (ρ=0.23–0.29, p<0.001) in healthy and glaucoma groups but showed a significant reduction with SE (ρ=−0.20, p<0.001) in the temporal RNFL of healthy subjects. RNFL measurements significantly decreased with VF MD (ρ=0.08–0.53, p<0.05) in subjects with POAG. When healthy subjects and subjects with glaucoma were matched to subgroups within a factor, significant differences in area under the curve (AUC) between subgroups were only found with SE AUCs increased significantly with disease severity, particularly in the global, inferior and superior measurements (p<0.001). Overall, the diagnostic performance of the inferior and global RNFL measurements were found to be more resilient to different factors.ConclusionDiagnostic accuracy in glaucoma was influenced by SE but could be mitigated by using controls with similar refractive characteristics. Increasing disease severity led to significantly better diagnostic accuracy. These factors should be considered when using OCT for glaucoma diagnosis in practice.

We report a rationally designed membrane‐intercalating conjugated oligoelectrolyte (COE), namely COE‐IC, which endows aerobic N2‐fixing bacteria Azotobacter vinelandii with a light‐harvesting ability that enables photosynthetic ammonia production. COE‐IC possesses an acceptor‐donor‐acceptor (A‐D‐A) type conjugated core, which promotes visible light absorption with a high molar extinction coefficient. Furthermore, COE‐IC spontaneously associates with A. vinelandii to form a biohybrid in which the COE is intercalated within the lipid bilayer membrane. In the presence of L‐ascorbate as a sacrificial electron donor, the resulting COE‐IC/A. vinelandii biohybrid showed a 2.4‐fold increase in light‐driven ammonia production, as compared to the control. Photoinduced enhancement of bacterial biomass and production of L‐amino acids is also observed. Introduction of isotopically enriched 15N2 atmosphere led to the enrichment of 15N‐containing intracellular metabolites, consistent with the products being generated from atmospheric N2.