PSMA-Targeted NIR Dye Conjugates for Tumor Imaging

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Solution Overview

Problem

Current diagnostic methods for prostate cancer, particularly those targeting prostate-specific membrane antigen (PSMA), face challenges such as low specificity, slow clearance, high non-specific uptake, and high manufacturing costs due to the use of large molecular weight agents and unstable linkers, leading to suboptimal tumor-to-background ratios and prolonged hospital stays.

Innovation Solution

Development of PSMA-targeted ligands linked to near-infrared (NIR) dyes via novel linkers that improve stability, pharmacokinetic properties, solubility, and tumor accumulation, with the option to vary the linker's charge for enhanced skin clearance and fluorescence, allowing for more precise and efficient imaging and surgery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If large molecular weight agents are used for PSMA-targeted imaging, then targeting capability is improved, but clearance speed decreases and hospital stay is prolonged

Engineering Contradiction:
Improvetargeting capabilityVSAvoidclearance speed
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent changes the molecular weight parameter by using small molecular weight compounds (e.g., 2-[(3-(1,3-dicarboxypropyl)ureido)pentanedioic acid] and its derivatives) instead of large molecular weight agents. This parameter change enables both rapid renal clearance and effective PSMA targeting, resolving the contradiction between targeting capability and clearance speed.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If conventional fluorescent dyes are used, then imaging capability is achieved, but tumor-to-background ratio is suboptimal due to high non-specific uptake

Engineering Contradiction:
Improveimaging capabilityVSAvoidnon-specific uptake
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent creates composite structures by conjugating PSMA-targeting ligands (such as DUPA derivatives) with near-infrared fluorescent dyes through specifically designed linkers. This composite approach combines the targeting specificity of the ligand with the imaging capability of the dye, while the linker design minimizes non-specific uptake and improves tumor-to-background ratio.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent introduces a linker as an intermediary component between the PSMA-targeting ligand and the fluorescent dye. This linker (which may include PEG chains or amino acid sequences) mediates the interaction, enabling the ligand to specifically bind PSMA while the dye provides imaging signal, thereby reducing non-specific uptake and improving imaging contrast.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If unstable linkers are used for conjugation, then manufacturing is simplified, but compound stability decreases leading to suboptimal imaging results

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidcompound stability
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent changes the chemical stability parameter of the linker by using stable amide bonds formed through carbodiimide chemistry (e.g., EDC/NHS coupling) or other stable conjugation methods. This ensures the conjugate remains stable during storage and administration while still being manufacturable through well-established chemical procedures.

Inventive Principle:
Principle #35Parameter changes

4Measurement precision

If visible light dyes are used for imaging, then fluorescence detection is possible, but penetration depth is limited due to tissue absorption

Engineering Contradiction:
Improvefluorescence detectionVSAvoidpenetration depth
Core Design Contradiction:
Measurement precisionVSLength of stationary object

Solution Approach 1:

The patent changes the wavelength parameter of the fluorescent dye by selecting near-infrared (NIR) dyes with absorption and emission maxima between 600-900 nm. This parameter change allows deeper tissue penetration (several centimeters) while maintaining fluorescence detection capability, as NIR light experiences less absorption and scattering by biological tissues compared to visible light.

Inventive Principle:
Principle #35Parameter changes

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 approach results in higher tumor-to-background ratios, faster skin clearance, and improved fluorescence intensity, enabling more accurate and efficient detection of PSMA-expressing tumors, including prostate cancer, with potential for reduced treatment duration and costs.

Implementation Method 1

fluorescent dyes that flow passively from the primary tumor into draining lymph nodes

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Implementation Method 2

PSMA-targeted ligands linked to near-infrared (NIR) dyes

Methodology Applied
Scientific EffectNear-infrared absorption and emission: Absorption (EM radiation)

Data Source

PatentEP3510399B1PSMA-targeted NIR dyes and their uses
Publication Date: 2023.03.01 ON TARGET LABORATORIES LLC
  • EP3510399B1 patent drawingFigure 1
  • EP3510399B1 patent drawingFigure 2
  • EP3510399B1 patent drawingFigure 3

AI summary

The present disclosure relates to prostate specific membrane antigen (PSMA) targeted compounds conjugated to near-infra red (NIR) dyes and methods for a method for synthesizing a compound of the formula (I).