Color-Coded Polyphosphazene Particles for Embolization

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Solution Overview

Problem

Existing medical particles used for diagnostic and therapeutic procedures often cause tissue irritation, induce adverse immune reactions, degrade rapidly in the body, and have poor suspension properties, making them unsuitable for long-term use and uniform delivery.

Innovation Solution

Development of color-coded polymeric microspheres and nanospheres made from poly[bis(trifluoroethoxy) phosphazene] that are biocompatible, stable, and easy to visualize, with incorporated dyes for size identification, and methods for their preparation and delivery using syringes and ultrasound imaging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If prior art particles are used in medical applications, then they can be delivered to treatment sites, but they cause tissue irritation and initiate adverse immune reactions

Engineering Contradiction:
Improvetissue irritation and immune reactionsVSAvoidbiocompatibility
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent changes the chemical composition parameters of the particle material from traditional polymers to polyphosphazene with specific side chains (fluorinated, hydroxyl, carboxyl groups). This parameter change fundamentally alters the biocompatibility profile, eliminating tissue irritation and immune reactions while maintaining therapeutic functionality.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material structure by combining polyphosphazene backbone with various functional side chains (fluorinated groups for stability, hydroxyl/carboxyl groups for biocompatibility). This composite approach at molecular level creates particles that simultaneously achieve chemical stability and biological compatibility.

Inventive Principle:
Principle #40Composite materials

2Duration of action of moving object

If prior art particles are used for long term presence, then they can provide sustained therapy, but they degrade rapidly releasing toxic compounds

Engineering Contradiction:
Improvelong term presenceVSAvoidtoxic degradation compounds
Core Design Contradiction:
Duration of action of moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical stability parameter by selecting polyphosphazene as the base polymer, which possesses inherent resistance to hydrolysis and enzymatic degradation. The fluorinated side chains further enhance this stability, allowing particles to maintain structural integrity for extended periods without degrading into toxic compounds.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent inverts this principle by creating long-lasting particles that do not require rapid degradation. The stable polyphosphazene structure allows particles to persist in the body for the desired therapeutic duration without needing to break down, eliminating the toxicity issue associated with degradation products.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Ease of operation

If particles are incorporated into delivery suspension, then they can be injected for treatment, but they settle out or float causing non-uniform delivery

Engineering Contradiction:
Improveuniform deliveryVSAvoidsuspension stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The patent changes the density parameter of particles by incorporating heavy atoms (such as barium or gold) into the polyphosphazene structure or as surface coatings. This density adjustment matches or exceeds the density of the delivery suspension medium, preventing particle settling and ensuring uniform distribution during injection.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses surface coating materials as intermediaries between the particle core and the delivery suspension. These coatings (such as surfactants or biocompatible polymers) modify surface properties to enhance dispersion stability and prevent aggregation, ensuring uniform suspension without compromising particle functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Object-affected harmful factors

If clear polymeric acrylate hydrogel beads are used, then they are biocompatible, but they are difficult to visualize in suspension

Engineering Contradiction:
ImprovevisualizabilityVSAvoidbiocompatibility
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent changes the optical parameter of particles by incorporating radiopaque materials (barium sulfate, gold) or fluorescent markers into the polyphosphazene structure. These additions provide X-ray visibility or fluorescent detection capabilities without significantly altering the biocompatible nature of the base polymer, as the radiopaque materials are used in controlled amounts and the polyphosphazene matrix maintains biological compatibility.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2545906B1Colour-coded and sized loadable polymeric particles for therapeutic and/or diagnostic applications and colour-coded syringe comprising the same
Publication Date: 2017.04.19 BOSTON SCI LTD
  • EP2545906B1 patent drawingFigure 1
  • EP2545906B1 patent drawingFigure 2
  • EP2545906B1 patent drawingFigure 3A

AI summary

Polymeric particles are provided for use in therapeutic and/or diagnostic procedures. The particles include poiy[bis(trifluoroethoxy) phosphazene] and/or a derivatives thereof which may be present throughout the particles or within an outer coating of the particles. The particles may also include a core having a hydrogel formed from an acrylic-based polymer. Such particles may be provided to a user in specific selected sizes to allow for selective embolization of certain sized blood vessels or localized treatment with an active component agent in specific clinical uses. Particles of the present invention may further be provided as color-coded microspheres or nanospheres to allow ready identification of the sized particles in use. Such color-coded microspheres or nanospheres may further be provided in like color-coded delivery or containment devices to enhance use identification and provide visual confirmation of the use of a specifically desired size of microspheres or nanospheres.