Disulfide-Linked Compound Nanoparticles for Tumor-Selective SN-38 Release

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Solution Overview

Problem

Existing methods for producing carrier-free nano-drugs do not effectively enable drug release specifically in tumor cells, lacking surfactants and efficient targeting mechanisms.

Innovation Solution

A compound represented by General Formula (1) or its salt, with specific alkyl and alkylene groups, is used to form nanoparticles that release the active ingredient SN-38 selectively in tumor cells due to higher glutathione concentrations, utilizing a method involving injection of a water-miscible organic solvent solution into water.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a carrier-free nano-drug is produced using existing top-down or bottom-up methods, then the nanoparticle can be formed without surfactants, but the drug cannot be released specifically in tumor cells

Engineering Contradiction:
Improvespecific drug release in tumor cellsVSAvoidtargeting mechanism
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The nanoparticle incorporates a disulfide bond-containing linker with specific local chemical properties that respond to the high glutathione concentration environment within tumor cells. This local chemical characteristic enables selective drug release only in the tumor cell interior where glutathione levels are elevated, while maintaining stability in normal cells with lower glutathione concentrations.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention exploits the parameter difference of glutathione concentration between tumor cells (high) and normal cells (low) to achieve selective drug release. The disulfide bond in the linker undergoes reduction cleavage specifically under the high glutathione conditions inside tumor cells, changing the chemical state of the drug-nanoparticle complex to release the active ingredient selectively at the target site.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the compound is designed for tumor cell targeting, then drug release occurs specifically in tumor cells, but rapid release in normal cells must be avoided

Engineering Contradiction:
Improveselective drug releaseVSAvoiddrug stability in normal cells
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The disulfide bond linker provides different stability characteristics in different biological environments: it remains stable in the low-glutathione environment of normal cells (maintaining drug stability) but undergoes reduction in the high-glutathione environment of tumor cells (enabling selective release). This spatially differentiated stability resolves the contradiction between selective release and drug stability.

Inventive Principle:
Principle #3Local quality

3Device complexity

If nanoparticles are formed without surfactants, then the structure is simplified, but the ability to control drug release is reduced

Engineering Contradiction:
Improvenanoparticle structureVSAvoidcontrolled drug release capability
Core Design Contradiction:
Device complexityVSEase of manufacture

Solution Approach 1:

The invention extracts and removes the surfactant component from the nanoparticle formulation, simplifying the overall structure. Instead of using surfactants for stabilization and control, the design relies on the intrinsic properties of the disulfide bond-containing linker molecule itself to provide both structural integrity and controlled release functionality, achieving simplification without sacrificing control capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The disulfide bond-containing linker serves multiple functions simultaneously: it acts as a connecting bridge between the nanoparticle core and the active ingredient, provides structural stabilization to the nanoparticle, and enables controlled drug release through glutathione-induced reduction. This multi-functionality compensates for the removal of surfactants while maintaining controlled release capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 compound or its salt, when formulated into nanoparticles, allows for stable transport and controlled release of SN-38 in tumor cells, avoiding rapid release in normal cells and providing a sustained drug delivery system.

Implementation Method 1

nanoparticles that release the active ingredient SN-38 selectively in tumor cells due to higher glutathione concentrations

Methodology Applied
Scientific EffectRedox reactions: Redox Reactions

Implementation Method 2

a method involving injection of a water-miscible organic solvent solution into water

Methodology Applied
Scientific EffectSolvation: Solvation

Data Source

PatentEP4631949A1Compound, nanoparticles, medicine and method for producing nanoparticles
Publication Date: 2025.10.15 THE JAPAN SCI & TECH AGENCY
  • EP4631949A1 patent drawingFigure 1~2
  • EP4631949A1 patent drawingFigure 3~4
  • EP4631949A1 patent drawingFigure 5~6

AI summary

A compound represented by General Formula (1) or a salt thereof, in which each of R1 and R2 independently represents an alkyl group having 1 to 4 carbon atoms, R1 and R2 may be bonded to each other to form a ring together with a carbon atom to which R1 and R2 are bonded, and each R3 independently represents an alkylene group having 1 to 4 carbon atoms; nanoparticles containing the compound or a salt thereof; a medicine containing the compound or a salt thereof; and a method for producing nanoparticles, including a step of injecting a water-miscible organic solvent solution of the compound or a salt thereof into water are provided.