Polymeric Gas-Core Microparticles for Multimodal Imaging

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Solution Overview

Problem

Current imaging technologies lack effective multimodal contrast agents that can simultaneously enhance both ultrasound and photoacoustic imaging, particularly for superficial tissue characterization and drug delivery, with limited spatial resolution and penetration depth.

Innovation Solution

Development of poly(n-butyl cyanoacrylate) microparticles with a gas core and a shell containing photoacoustic agents like indocyanine green, gold nanoparticles, or iron oxide nanoparticles, which are suitable for both ultrasound and photoacoustic imaging, and can be used for drug delivery and photodynamic therapy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If conventional ultrasound imaging is used, then penetration depth is improved, but spatial resolution for superficial lesions deteriorates

Engineering Contradiction:
Improvepenetration depthVSAvoidspatial resolution
Core Design Contradiction:
Length of moving objectVSMeasurement precision

Solution Approach 1:

The patent combines ultrasound and photoacoustic imaging modalities into a single dual-modal contrast agent system. The microbubbles provide ultrasound contrast while embedded fluorophores provide photoacoustic signal, allowing simultaneous acquisition of both imaging modes to resolve the trade-off between penetration depth and spatial resolution for superficial lesions

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The contrast agent is designed with multi-functionality, serving both as an ultrasound contrast agent and a photoacoustic imaging agent. The microbubble structure with embedded fluorophores enables the single agent to perform multiple imaging functions, addressing the limitation of conventional single-modal agents

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

2Adaptability or versatility

If multimodal contrast agents are developed, then imaging capabilities are improved, but device complexity increases

Engineering Contradiction:
Improveimaging capabilitiesVSAvoidagent structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent embeds fluorophore molecules within the shell structure of polymeric microbubbles. This nested configuration allows the fluorophores to be contained within the microbubble matrix, providing photoacoustic functionality while maintaining the ultrasound contrast properties of the microbubble structure, thus achieving multimodality without excessive complexity

Inventive Principle:
Principle #7Nested doll (Nesting)

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 multimodal contrast agent provides enhanced imaging capabilities for superficial lesions, including skin cancer, sentinel lymph node mapping, and vascular inflammation, while also enabling effective drug delivery across the blood-brain barrier, with improved spatial resolution and penetration depth.

Implementation Method 1

Photoacoustic imaging is a rapidly developing technology enabling a sensitive assessment of molecular and functional tissue characteristics

Methodology Applied
Scientific EffectPhotoacoustic effect: Photoacoustic Effect

Implementation Method 2

poly(n-butyl cyanoacrylate) (PCBA)-based hard-shell microbubbles, which are generally known for functional and molecular ultrasound imaging

Methodology Applied
Scientific EffectAcoustic cavitation: Acoustic Cavitation

Implementation Method 3

having a gas core and carrying at least one photoacoustic agent in its PBCA shell that stabilizes the gas core

Methodology Applied
Scientific EffectSurface tension: Surface Tension

Data Source

PatentEP3223864B1Multimodal ultrasound and photoacoustic contrast agent based on polymeric microparticles
Publication Date: 2020.01.08 FUJIFILM VISUALSONICS
  • EP3223864B1 patent drawingFigure 1A~1D
  • EP3223864B1 patent drawingFigure 2~3E
  • EP3223864B1 patent drawingFigure 4~5D

AI summary

The invention provides a multimodal ultrasound and photoacoustic contrast agent based on polymeric microparticles having a gas core and carrying at least one photoacoustic agent in its shell that stabilizes the gas core, for use in ultrasound and photoacoustic imaging. Such multimodal ultrasound and photoacoustic contrast agent is also suitable as a carrier of drugs and for use in photodynamic therapy, and for tissue imaging ex vivo.