Safety, pharmacokinetics, and pharmacodynamics of LBP-EC01, a CRISPR-Cas3-enhanced bacteriophage cocktail, in uncomplicated urinary tract infections due to Escherichia coli (ELIMINATE): the randomised, open-label, first part of a two-part phase 2 trial.

Background: The rate of antibiotic resistance continues to grow, outpacing small-molecule-drug development efforts. Novel therapies are needed to combat this growing threat, particularly for the treatment of urinary tract infections (UTIs), which are one of the largest contributors to antibiotic use and associated antibiotic resistance. LBP-EC01 is a novel, genetically enhanced, six-bacteriophage cocktail developed by Locus Biosciences (Morrisville, NC, USA) to address UTIs caused by Escherichia coli, regardless of antibiotic resistance status.

A selenium analogue of firefly D-luciferin with red-shifted bioluminescence emission.

A selenium analogue of amino-D-luciferin, aminoseleno-D-luciferin, is synthesized and shown to be a competent substrate for the firefly luciferase enzyme. It has a red-shifted bioluminescence emission maximum at 600 nm and is suitable for bioluminescence imaging studies in living subjects.

Sensing cooperativity in ATP hydrolysis for single multisubunit enzymes in solution.

In order to operate in a coordinated fashion, multisubunit enzymes use cooperative interactions intrinsic to their enzymatic cycle, but this process remains poorly understood. Accordingly, ATP number distributions in various hydrolyzed states have been obtained for single copies of the mammalian double-ring multisubunit chaperonin TRiC/CCT in free solution using the emission from chaperonin-bound fluorescent nucleotides and closed-loop feedback trapping provided by an Anti-Brownian ELectrokinetic trap. Observations of the 16-subunit complexes as ADP molecules are dissociating shows a peak in the bound ADP number distribution at 8 ADP, whose height falls over time with little shift in the position of the peak, indicating a highly cooperative ADP release process which would be difficult to observe by ensemble-averaged methods.

Molecules and methods for super-resolution imaging.

By looking at a fluorescently labeled structure one molecule at a time, it is possible to side-step the optical diffraction limit and obtain "super-resolution" images of small nanostructures. In the Moerner Lab, we seek to develop both molecules and methods to extend super-resolution fluorescence imaging. Methodologies and protocols for designing and characterizing fluorophores with switchable fluorescence required for super-resolution imaging are reported.

Azido push-pull fluorogens photoactivate to produce bright fluorescent labels.

Dark azido push-pull chromophores have the ability to be photoactivated to produce bright fluorescent labels suitable for single-molecule imaging. Upon illumination, the aryl azide functionality in the fluorogens participates in a photochemical conversion to an aryl amine, thus restoring charge-transfer absorption and fluorescence. Previously, we reported that one compound, DCDHF-V-P-azide, was photoactivatable.

DCDHF fluorophores for single-molecule imaging in cells.

There is a persistent need for small-molecule fluorescent labels optimized for single-molecule imaging in the cellular environment. Application of these labels comes with a set of strict requirements: strong absorption, efficient and stable emission, water solubility and membrane permeability, low background emission, and red-shifted absorption to avoid cell autofluorescence. We have designed and characterized several fluorophores, termed "DCDHF" fluorophores, for use in live-cell imaging based on the push-pull design: an amine donor group and a 2-dicyanomethylene-3-cyano-2,5-dihydrofuran (DCDHF) acceptor group, separated by a pi-rich conjugated network.

Cy3-Cy5 covalent heterodimers for single-molecule photoswitching.

Covalent heterodimers of the Cy3 and Cy5 fluorophores have been prepared from commercially available starting materials and characterized at the single-molecule level. This system behaves as a discrete molecular photoswitch, in which photoexcitation of the Cy5 results in fluorescence emission or, with a much lower probability, causes the Cy5 to enter into a long-lived, but metastable, dark state. Photoinduced recovery of the emissive Cy5 is achieved by very low intensity excitation (5 W cm(-2)) of the Cy3 fluorophore at a shorter wavelength.

A photoactivatable push-pull fluorophore for single-molecule imaging in live cells.

We have reengineered a red-emitting dicyanomethylenedihydrofuran push-pull fluorophore so that it is dark until photoactivated with a short burst of low-intensity violet light. Photoactivation of the dark fluorogen leads to conversion of an azide to an amine, which shifts the absorption to long wavelengths. After photoactivation, the fluorophore is bright and photostable enough to be imaged on the single-molecule level in living cells.

Bulk and single-molecule characterization of an improved molecular beacon utilizing H-dimer excitonic behavior.

Pairs of fluorophores in close proximity often show self-quenching of fluorescence by the well-known H-dimer mechanism. We use a pair of fluorophores in the new dicyanomethylenedihydrofuran (DCDHF) dye family in the design and characterization of a new fluorescent probe for nucleic acid detection, which we refer to as a self-quenched intramolecular dimer (SQuID) molecular beacon (MB). We obtain a quenching efficiency of 97.

Toward nanometer-scale optical photolithography: utilizing the near-field of bowtie optical nanoantennas.

Optically resonant metallic bowtie nanoantennas are utilized as fabrication tools for the first time, resulting in the production of polymer resist nanostructures <30 nm in diameter at record low incident multiphoton energy densities. The nanofabrication is accomplished via nonlinear photopolymerization, which is initiated by the enhanced, confined optical fields surrounding the nanoantenna. The position, size, and shape of the resist nanostructures directly correlate with rigorous finite-difference time-domain computations of the field distribution, providing a nanometer-scale measurement of the actual field confinement offered by single optical nanoantennas.