Siderophore-Daptomycin Conjugates for Gram-Negative Uptake
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Solution Overview
Problem
Current antibiotics are ineffective against Gram-negative bacteria due to their outer membrane permeability barriers, and there is a dire need for new antibiotics to address the rise of antibiotic-resistant infections.
Innovation Solution
Development of siderophore-antibiotic conjugates that utilize the bacterial iron transport system to deliver antibiotics into Gram-negative bacteria, exploiting the natural iron sequestration processes to bypass resistance mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If daptomycin is used to treat Gram-negative bacteria, then antibacterial activity is improved, but the outer membrane permeability barrier prevents the antibiotic from reaching the target
Solution Approach 1:
The patent uses siderophores as intermediary molecules that exploit the bacterial iron transport system to mediate the delivery of daptomycin across the outer membrane barrier. The siderophore-daptomycin conjugate acts as a carrier that bypasses the permeability restriction by hijacking the natural iron uptake pathways (FepA, FhuA, FhuD receptors) of Gram-negative bacteria, thereby enabling the antibiotic to reach its target site within the periplasmic space.
2Reliability
If conventional antibiotics are used, then treatment of Gram-positive infections is effective, but resistance develops rapidly due to overuse and bacterial adaptation
Solution Approach 1:
The patent converts the harmful effect of bacterial iron sequestration mechanisms into a beneficial delivery pathway. By designing siderophore-daptomycin conjugates, the invention exploits the bacteria's own iron uptake systems (which are essential for their survival and growth) to deliver the antibiotic directly into the cell. This approach turns the bacteria's metabolic vulnerability into a targeted delivery mechanism, achieving effective treatment while potentially reducing resistance development through precise intracellular action.
3Ease of operation
If siderophore-antibiotic conjugates are developed, then uptake through iron transport system is achieved, but molecular weight increases beyond porin diffusion limits
Solution Approach 1:
The patent inverts the conventional approach to overcoming membrane barriers. Instead of attempting to reduce molecular weight to enable passive diffusion through porins, the invention increases molecular weight by conjugating daptomycin with siderophores, thereby enabling active transport through the iron uptake system. This inversion transforms the size limitation into an advantage by utilizing the bacteria's energy-dependent transport mechanisms that are specifically designed to handle larger, complex molecules.
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
The siderophore-antibiotic conjugates demonstrate significantly enhanced antibacterial activity against Gram-negative species, including multi-drug resistant strains, by facilitating the uptake of antibiotics through the bacterial iron transport system, effectively treating infections caused by Pseudomonas aeruginosa and Acinetobacter baumanni.
Implementation Method 1
bacteria must assimilate nutrients. One nutrient that is absolutely essential for growth of virtually all forms of life, including bacteria, is iron. Competition for iron between a host and pathogenic bacteria is one of the most important factors in determining the course of a bacterial infection. Due to the extreme insolubility of ionic forms of iron, bacteria and fungi have evolved highly specific iron sequestration processes that involve energy-dependent active transport of relatively low-molecular-weight iron chelators called siderophores.
Implementation Method 2
bacteria and fungi have evolved highly specific iron sequestration processes that involve energy-dependent active transport of relatively low-molecular-weight iron chelators called siderophores
Implementation Method 3
In Gram-negative bacteria, iron-siderophore complexes are recognized and are bound by specific outer-membrane receptors (OMR) at the cell surface. Binding of the siderophore-iron complexes initiates the active transport process that translocates the iron complex to the periplasm.
Implementation Method 4
Daptomycin works by disrupting bacterial membrane function. It inserts into and aggregates in the cell membrane and induces changes that induce depolarization and eventual inhibition of protein, DNA, and RNA biosynthesis.
Data Source
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AI summary
A compound, comprising: an Fe(III)-binding and/or Fe(III)-bound siderophore; one or more optional linker covalently bound to the siderophore; and daptomycin covalently bound to the linker, or, if no linker is present, then to the siderophore; or pharmaceutically acceptable salt or solvate thereof.