Porous Embolization Particles for Stable Vascular Integration
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Solution Overview
Problem
Existing embolization particles, particularly spherical ones, face issues such as non-precise size, clumping, and migration due to smooth surfaces and compression properties, leading to ineffective integration and potential catheter blockages, and they often require aseptic liquid processing and have limited shelf-life, with some being difficult to dehydrate or rehydrate.
Innovation Solution
Development of substantially spherical porous embolization particles with interconnected macropores, made from crosslinked PVA polymer foam, which can be dehydrated and rehydrated, reducing clumping and improving stability within the vasculature, using a method involving mixing PVA with a porogen, crosslinking, and controlled drying, followed by hydration in a saline solution with pressure reduction to remove air bubbles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If spherical embolization particles with smooth surfaces are used, then they can penetrate deeper into the vasculature and infrequently occlude delivery catheters, but they may affect stable integration within the occlusive mass and allow undesirable migration under blood vessel pressure
Solution Approach 1:
The patent applies local quality by creating surface macropores (1-50 microns) specifically on the particle surface while maintaining the spherical shape. This localized structural modification provides anchoring points for clot attachment at the surface level without compromising the overall spherical geometry that enables deep catheter penetration. The surface pores create irregularities that enhance integration stability while preserving the beneficial spherical form factor.
2Ease of operation
If pre-hydrated particles are delivered in saline solution, then they are ready for immediate use, but they float to the top of contrast media until equilibrated and have limited shelf-life with higher manufacturing costs
Solution Approach 1:
The patent applies parameter changes by modifying the particle's hydration state and density characteristics. The surface macropores enable controlled water absorption and contrast media equilibration. Particles can be delivered in a partially hydrated state that allows them to sink in contrast media without requiring full equilibration time, extending shelf-life and reducing manufacturing costs while maintaining operational readiness. The pore structure enables gradual hydration that prevents floating issues.
3Reliability
If particles are dehydrated to extend shelf-life and reduce cost, then they are easier to store and manufacture, but they may crack or permanently deform from spherical shape
Solution Approach 1:
The patent applies porous materials by incorporating surface macropores (1-50 microns) that act as stress relief zones during dehydration and rehydration cycles. These pores accommodate volume changes and prevent cracking by providing expansion space. The porous structure maintains spherical integrity during dehydration by distributing mechanical stresses uniformly, preventing the permanent deformation that would occur in dense non-porous particles. The pores enable reversible hydration without structural damage.
4Ease of manufacture
If traditional non-spherical PVA foam particles are used, then they are easier to manufacture, but they have non-precise size and open edges that cause clumping and catheter plugging
Solution Approach 1:
The patent applies spheroidality by forming particles into spherical shapes with controlled surface macropores. The spherical geometry provides precise, uniform dimensions that prevent clumping and catheter plugging while maintaining ease of manufacture through droplet-based formation methods. The spherical shape with surface pores combines the manufacturing simplicity of traditional methods with the dimensional precision and flow characteristics of engineered spherical particles, eliminating the open edge problems of irregular particles.
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 particles exhibit improved firmness and uniform hydration, reducing clumping and stratification, allowing for deeper penetration and stable clot formation, while being easier to handle and store, with enhanced catheter compatibility and reduced risk of migration.
Implementation Method 1
The particle has a surface portion and an interior portion. The interior contains pores, many of which are interconnected. Some of the pores are exposed to the surface of the particles.
Implementation Method 2
hydrating the dehydrated particle by suspending the particle in a saline solution with a pressure reduction applied to remove air bubbles from the particle
Implementation Method 3
reacting the mixture for a period of time at elevated temperatures until the polyvinyl alcohol is crosslinked to form a PVA sponge product
Data Source
Figure 1a~1b
Figure 1c~1d
Figure 1e~1f
AI summary
The present invention relates to porous embolization devices, methods of making and using the devices as well as methods and devices to hydrate and deliver embolization particles.