Liquid Polymeric Embolization Composition With Temporary Radiopacity
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Solution Overview
Problem
Existing embolizing compositions face challenges such as difficulty in handling, sedimentation of radiopaque compounds, excessive shielding during fluoroscopic monitoring, rapid dissolution of water-soluble contrast agents, and complex synthesis of covalently bonded iodine-based agents, which compromise the effectiveness and safety of vascular embolization procedures.
Innovation Solution
A liquid polymeric composition comprising a polymer and radiopaque molecule dissolved in a non-physiological solvent, which forms a cohesive radiopaque precipitate upon contact with physiological conditions, allowing easy preparation, controlled radiopacity, and gradual radiopacity loss for effective monitoring and bioresorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If water-soluble contrast agents are used, then radiopacity monitoring is improved, but rapid dissolution and removal from injection site occurs leading to loss of radiopacity and potential side effects
Solution Approach 1:
The patent changes the solubility parameter of the contrast agent by using lipophilic (fat-soluble) compounds instead of water-soluble ones. The contrast agent is dissolved in a lipophilic solvent in the injection composition, and upon injection into the bloodstream, the solvent transfers the contrast agent to blood lipoproteins, maintaining radiopacity without rapid dissolution. This parameter change resolves the contradiction between achieving radiopacity monitoring and maintaining duration of action.
2Stability of the object's composition
If covalently polymer-bonded iodine-based contrast agents are used, then homogeneous radiopacity over time is achieved, but complex synthesis and deleterious effect on precipitation behavior occur
Solution Approach 1:
The patent introduces lipoproteins as an intermediary carrier. Instead of covalently bonding the contrast agent to the polymer (complex synthesis), the lipophilic contrast agent is carried by lipoproteins in the blood, which naturally transport lipophilic substances. This intermediary approach achieves homogeneous radiopacity distribution without complex chemical synthesis and without interfering with the polymer's precipitation behavior.
3Measurement precision
If tantalum powder is used as radiopaque compound, then radiopacity is achieved, but sedimentation compromises visual control and excessive shielding occurs during fluoroscopic monitoring
Solution Approach 1:
The patent replaces permanent radiopaque materials like tantalum with biodegradable alternatives. The contrast agent used is lipophilic and can be temporarily carried by lipoproteins, providing radiopacity during the procedure without permanent implantation. This allows for temporary, controllable radiopacity that disappears after the procedure, improving handling and reducing excessive shielding issues.
4Measurement precision
If highly water soluble contrast agents are used, then radiopacity visualization is improved, but leaching from embolized region causes local and systemic side effects
Solution Approach 1:
The patent changes the solubility parameter from water-soluble to lipophilic (fat-soluble). The contrast agent is designed to be soluble in lipophilic solvents used in the embolization composition but not highly water-soluble. Upon injection, it binds to blood lipoproteins rather than freely leaching into the bloodstream, maintaining visualization while reducing toxicity and side effects.
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 composition enables easy handling, forms a cohesive and homogeneous solid precipitate for adequate monitoring, and bioresorbs in a clinically relevant time frame, reducing the need for reintervention and minimizing side effects.
Implementation Method 1
a polymer that transitions from a liquid to a solid upon being subject to physiological conditions
Implementation Method 2
transition to a solid state (precipitate) at the delivery site
Implementation Method 3
Radiopacity of embolizing compositions is important in order to monitor the injection of the composition in the vascular site and to confirm the completeness and the quality of the embolization procedure
Data Source
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AI summary
The invention refers to a liquid polymeric composition comprising: (a) from about 2 to about 20 weight percent of a polymer; (b) from about 5 to about 40 weight percent of a radiopaque molecule with a molecular weight below 2000 g/mol; and (c) from about 40 to about 93 weight percent of a non-physiological solvent or solvent system; wherein (i) the sum of the weight percent of all components in the composition is 100, (ii) the polymer and the radiopaque molecule are not covalently bound and are both dissolved in the non-physiological solvent or solvent system, and (iii) the polymer is soluble in the non-physiological solution and insoluble in a physiological solution at room temperature, and (iv) the liquid polymeric composition is capable of forming, upon contact with physiological conditions, a radiopaque precipitate which maintains at least 50% of its radiopacity during at least 30 minutes and loses at least 50% of its radiopacity in less than 6 months.