Triaryl Phosphonium Compounds for Gram-Negative Membrane Penetration
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Solution Overview
Problem
Existing antibiotics face challenges in penetrating the outer membrane and cell wall of gram-negative bacteria due to their double-membrane cell envelope structure and multidrug efflux systems, leading to antibiotic resistance and limited efficacy.
Innovation Solution
Development of compounds comprising a triaryl phosphonium cation and a linker, such as a pleuromutilin or pleuromutilin analog, designed to permeabilize the bacterial membrane and retain the antibiotic inside the pathogen by using a hydrolysable linker to dissociate the TPP+ moiety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing antibiotics are used to treat gram-negative bacteria, then the treatment approach is simple and straightforward, but the antibiotics cannot effectively penetrate the outer membrane and cell wall due to the double-membrane structure and multidrug efflux systems
Solution Approach 1:
The patent introduces a cell-penetrating peptide (CPP) as an intermediary component that facilitates antibiotic penetration through the gram-negative bacterial outer membrane and cell wall. The CPP acts as a mediator that enables the antibiotic to cross the membrane barrier and efflux systems that would otherwise prevent effective treatment
Solution Approach 2:
The invention creates a composite structure consisting of a cell-penetrating peptide conjugated to an antibiotic molecule. This composite material combines the membrane-penetration capabilities of the CPP with the antimicrobial activity of the antibiotic, enabling effective delivery of the therapeutic agent through the bacterial defense mechanisms
2Reliability
If antibiotics are designed to overcome the membrane barrier, then penetration capability improves, but the complexity of the drug molecule increases
Solution Approach 1:
The patent segments the therapeutic function into two distinct components: a cell-penetrating peptide responsible for membrane crossing and an antibiotic moiety responsible for antimicrobial activity. This segmentation allows each component to be optimized independently while maintaining overall functionality
Solution Approach 2:
The conjugate structure is designed to be dynamic, with the CPP and antibiotic portions working together in a coordinated manner. The CPP facilitates entry into the bacterial cell, and once inside, the antibiotic component is released or activated to exert its antimicrobial effect, creating a dynamic delivery system
3Reliability
If the bacterial cell envelope structure is targeted for penetration, then drug delivery effectiveness improves, but the bacteria's resistance mechanisms become more challenging to overcome
Solution Approach 1:
The patent exploits the electrostatic properties of the bacterial cell envelope, which is highly negatively charged, by using a positively charged cell-penetrating peptide. The harmful negative charge that contributes to membrane barrier function is converted into a beneficial attraction force that guides the CPP to the membrane and facilitates penetration
Solution Approach 2:
The invention changes the physical-chemical parameters of the drug delivery system by using a CPP with specific charge, size, and hydrophobicity characteristics. These parameter changes enable the conjugate to interact with and penetrate the bacterial cell envelope in ways that traditional antibiotics cannot
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 compounds effectively penetrate and inhibit gram-negative bacteria, overcoming resistance mechanisms and enhancing antibiotic efficacy against pathogens like Escherichia coli and Klebsiella pneumoniae.
Implementation Method 1
The gram-negative bacterial cell wall is a rigid and cross-linked matrix of peptidoglycan that is enriched in carboxyl and amino groups. The outer membrane consists of phospholipids on the inside and lipopolysaccharides on the outside in a structure that confers the membrane barrier and efflux activity. The impermeability of drugs into gram-negative bacteria is rooted in these bacteria's double-membrane cell envelope structure which is highly negatively charged.
Implementation Method 2
Lipophilic cations such as the TPP+ moiety have been widely used to target drugs and probes into the mitochondria where it was first described in 1970. The driving force for the accumulation of the lipophilic cation into mitochondria relies on the negative membrane potential maintained across the mitochondrial inner membrane.
Data Source
AI summary
Disclosed herein are compounds of the formulas (I) as well as analogs thereof, wherein the variables are defined herein. Also provided are pharmaceutical compositions thereof. In some aspects, the compounds and compositions provided herein may be used to contact Gram-negative bacteria. Also provided are methods of administering compounds and compositions provided herein to a patient in need thereof, for example, for the treatment or prevention of bacterial infections or diseases.