Multimerized Fluorescent Dyes on Polyether Scaffolds
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Solution Overview
Problem
Conventional small molecule fluorescent dyes have limited brightness due to self-quenching and unspecific binding, limiting the fluorescence intensity of biomolecule conjugates, and existing solutions like phycobiliproteins face stability and availability issues.
Innovation Solution
Fluorescent dyes multimerized on branched polyether scaffolds, such as multi-arm polyethylene glycols, which provide high fluorescence intensity without quenching and improved stability, allowing for a high degree of fluorophore labeling on biomolecules like antibodies without loss of activity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If multiple fluorescent dye molecules are conjugated to biomolecules to increase brightness, then fluorescence intensity should increase proportionally, but self-quenching mechanisms cause fluorescence intensity to decrease at higher degrees of labeling
Solution Approach 1:
The invention divides the fluorescent labeling system into separate functional components: a water-soluble core structure that provides spacing and a fluorescent dye attached to this core. The core acts as a spacer that physically separates multiple dye molecules conjugated to the same biomolecule, preventing them from coming into close proximity where self-quenching would occur. This segmentation approach allows multiple dyes to be attached while maintaining individual fluorescence activity.
Solution Approach 2:
The water-soluble core structure serves as an intermediary element between the biomolecule and the fluorescent dye. This core with its hydrophilic groups (such as sulfonate, phosphate, or carboxylate) creates a hydrophilic barrier that prevents direct hydrophobic interactions between aromatic chromophores of adjacent dye molecules. The intermediary core thus mediates the interaction by providing both structural support and quenching prevention through its water-soluble character.
2Illumination intensity
If substituents are added to flat aromatic dye molecules to reduce dimerization, then water solubility and brightness improve, but the number of functionalization sites on biomolecules remains limited
Solution Approach 1:
The invention segments the labeling system into a reusable water-soluble core component and the fluorescent dye component. The core contains multiple identical functionalization sites (such as multiple carboxylate or amine groups) that can all react with the biomolecule. This segmentation allows the same core structure with its multiple sites to be used repeatedly, overcoming the limitation of having only a few functionalization sites on traditional dye molecules.
Solution Approach 2:
The invention changes the chemical parameters of the dye construct by attaching the fluorescent dye to a water-soluble core structure rather than directly to the biomolecule. This parameter change in the molecular architecture transforms the limited functionalization sites of traditional dyes into multiple accessible sites on the core, enabling higher degrees of labeling while maintaining the dye's brightness and water solubility characteristics.
3Illumination intensity
If phycobiliproteins are used to achieve high fluorescence intensity, then brightness increases significantly, but stability against non-physiological conditions and photostability are limited
Solution Approach 1:
The invention copies the successful multichromophore strategy of phycobiliproteins but implements it using synthetic organic chemistry principles rather than relying on protein structure. Instead of using multiple fluorophore subunits held together by protein bonds (which are sensitive to denaturation), the invention uses a stable water-soluble core with covalently attached dyes and covalent attachment to the biomolecule. This copying approach achieves similar high brightness while improving stability against non-physiological conditions.
Solution Approach 2:
The invention creates a composite fluorescent labeling system combining a water-soluble core structure (with hydrophilic groups like sulfonate, phosphate, or carboxylate) and a fluorescent dye molecule. This composite material integrates the water solubility and stability properties of the core with the high brightness of the dye, producing a conjugate that is more stable than phycobiliproteins while maintaining high fluorescence intensity. The composite nature allows optimization of both stability and brightness independently.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Achieves phycobiliprotein-like fluorescence intensity with low unspecific background staining and stability against environmental conditions, enabling high degrees of labeling without activity loss or increased unspecific binding.
Implementation Method 1
Fluorescent dyes multimerized on branched polyether scaffolds, such as multi-arm polyethylene glycols, which provide high fluorescence intensity without quenching
Implementation Method 2
Most of the aforementioned fluorescent dye molecules, such as rhodamines or cyanines, contain planar aromatic chromophores, which are prone to hydrophobic interactions leading to dye-dye dimers with low or no fluorescence
Data Source
AI summary
The invention is directed to a fluorescent dye according to the general formula I:withC is a core moiety comprising 20 to 200 atoms;S same or different ether residues comprising 1 to 10 carbon atoms;n is an integer ranging from 2 to 500;m is an integer ranging from 0 to 500;x is an integer ranging from 2 to 50;y is an integer ranging from 1 to 50;R same or different residue comprising a reactive group capable of forming a covalent bond with a biomolecule;F same or different fluorophores covalently bound to (S)n.The fluorescent dyes can be conjugated to a biomolecule and used for flow cytometry and/or by fluorescence microscopy.