Crosslinked Embolization Microspheres for Controlled Swelling and Occlusion

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Solution Overview

Problem

Existing nonbiodegradable embolization microspheres face challenges such as variable swelling, poor mechanical properties, and difficulty in achieving precise, targeted vascular occlusion due to issues like sedimentation, inhomogeneous suspension, and unpredictable localization within blood vessels.

Innovation Solution

Development of nonbiodegradable embolization microspheres with a hydrophilic crosslinked polymer matrix, optimized with a controlled degree of swelling, elasticity, and compressibility, using specific monomers and transfer agents to enhance mechanical properties and ensure homogeneous suspension.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If nonbiodegradable embolization microspheres are used for permanent embolization, then embolization durability is improved, but mechanical properties and swelling control deteriorate

Engineering Contradiction:

Improveembolization durabilityVSAvoidmechanical properties

Core Design Contradiction:

Duration of action of stationary objectVSStrength

Solution Approach 1:

The patent uses composite polymer materials comprising a hydrophilic polymer matrix (such as polyacrylamide, polyvinyl alcohol, or carboxymethyl cellulose) crosslinked with specific crosslinking agents. This composite structure provides both permanent embolization durability and improved mechanical properties with controlled swelling characteristics.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent optimizes multiple parameters including crosslinking density, polymer composition ratios, and microsphere size distribution to achieve the desired balance between durability, mechanical strength, and swelling control. Specific crosslinking ratios and polymer concentrations are predetermined to ensure optimal performance.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If microsphere size is reduced for distal arterial access, then targeting precision is improved, but suspension homogeneity and localization control deteriorate

Engineering Contradiction:

Improvetargeting precisionVSAvoidsuspension homogeneity

Core Design Contradiction:

Measurement precisionVSStability of the object's composition

Solution Approach 1:

The patent employs a controlled size distribution range for microspheres (e.g., 10-100 micrometers) rather than uniform small sizes, optimizing the balance between distal arterial access capability and suspension stability. Surface properties and density are also adjusted to prevent sedimentation while maintaining targeting precision.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If microspheres are loaded with therapeutic agents for chemoembolization, then treatment efficacy is improved, but manufacturing complexity and loading control difficulty increase

Engineering Contradiction:

Improvetreatment efficacyVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent incorporates therapeutic agents during the microsphere manufacturing process itself, rather than attempting post-manufacturing loading. The polymer matrix is designed to accommodate and release the therapeutic agent in a controlled manner, simplifying the overall process while ensuring uniform distribution and predictable release kinetics.

Inventive Principle:

Principle #10Preliminary action

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 microspheres achieve precise, targeted, and permanent vascular occlusion with improved mechanical properties, allowing controlled swelling and stability during injection, reducing complications and enhancing treatment efficacy.

Implementation Method 1

a crosslinked matrix which is based on at least: a) 20% to 95% of hydrophilic monomer

Methodology Applied

Scientific EffectHydrophilic swelling: Hydrogel

Implementation Method 2

c) 1.5% to less than 6% of transfer agent selected from alkyl halides and cycloaliphatic or aliphatic thiols

Methodology Applied

Scientific EffectChain transfer reaction:

Data Source

PatentUS12552891B2Non-degradable embolisation microsphere

Publication Date: 2026.02.17 GUERBET SA

AI summary

The invention relates to non-biodegradable embolisation microspheres comprising a cross-linked matrix, the matrix being based on at least: a) from 20% to 95% of hydrophilic monomer; b) from 1% to 15% of a non-biodegradable hydrophilic cross-linking monomer; and c) from 1.5% to less than 6% of transfer agent selected from alkyl halides and cycloaliphatic or aliphatic thiols having in particular from 2 to 24 carbon atoms, and optionally having another functional group selected from amino, hydroxy and carboxy groups. The invention further relates to a pharmaceutical composition comprising non-biodegradable embolisation microspheres according to the invention in conjunction with a pharmaceutically acceptable vehicle, advantageously for parenteral administration. The invention further relates to a kit comprising a pharmaceutical composition comprising non-biodegradable embolisation microspheres according to the invention in conjunction with a pharmaceutically acceptable vehicle for parenteral administration, and at least one injection means.