High Tg PEA Polymer Biodegradable Stent Radial Strength
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Solution Overview
Problem
Biodegradable stents for vascular interventions face challenges such as intimal flaps, thrombosis, and restenosis due to lack of radial strength and stability, particularly in self-expandable designs for vulnerable plaque, where lower radial strength is required.
Innovation Solution
A biodegradable implantable device made from amorphous or semi-crystalline poly(ester amide) (PEA) polymers with high glass transition temperature (Tg) is developed, providing mechanical integrity, shelf life stability, and tunable degradation properties, which can include bioactive agents for enhanced therapeutic effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If highly crystalline polymers such as poly(L-lactic acid) are used to provide high radial strength, then radial strength is improved, but degradation rate increases and mechanical integrity over time deteriorates
Solution Approach 1:
The patent changes the chemical composition parameters of the polymer by incorporating amino acid-derived monomers with specific side chains (aliphatic, aromatic, heterocyclic groups) to achieve the desired balance between radial strength and degradation rate. This compositional parameter adjustment allows tuning of both mechanical properties and biodegradation characteristics without relying solely on crystallinity
Solution Approach 2:
The patent employs composite polymer structures combining different amino acid-derived monomers (e.g., leucine, phenylalanine, tyrosine units) to create a material that exhibits both high radial strength through controlled crystallinity and appropriate degradation rate through amorphous phase design, achieving properties superior to single-component polymers
2Adaptability or versatility
If self-expandable stent designs are used for vulnerable plaque, then adaptability to vulnerable plaque is improved, but radial strength deteriorates
Solution Approach 1:
The patent adjusts the polymer composition parameters by selecting specific amino acid derivatives and controlling their ratios to achieve optimal balance between radial strength and self-expandability. The presence of certain side chains (aliphatic, aromatic, heterocyclic groups) influences both the mechanical recovery properties and the degradation profile, enabling self-expandable designs with sufficient strength
3Reliability
If biodegradable polymers are used to allow degradation within specified timeframe, then biocompatibility is improved, but mechanical integrity deteriorates
Solution Approach 1:
The patent modifies the polymer degradation parameters by controlling the incorporation of hydrolytically labile ester bonds alongside stable amide bonds from amino acid backbones. This allows tuning of degradation rate to match the healing timeline while maintaining adequate mechanical support during the critical early period
Solution Approach 2:
The patent creates a composite structure at the molecular level combining rapidly degrading ester linkages with slowly degrading amide linkages, resulting in a material that maintains mechanical integrity through the stable amide backbone while allowing controlled degradation through ester bond hydrolysis, achieving both biocompatibility and sustained strength
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 high Tg PEA polymers ensure the biodegradable device maintains mechanical integrity and stability while degrading within a specified timeframe, reducing the risk of intimal flaps and thrombosis, and can be designed to include bioactive agents for improved vascular health.
Implementation Method 1
amorphous or semi-crystalline poly(ester amide) (PEA) polymer with a high glass-transition temperature (Tg)... Such PEA polymers impart mechanical integrity and shelf life stability to the biodegradable implantable device
Data Source
AI summary
The present invention provides an implantable device formed from an amorphous or semi-crystalline PEA polymer with a high Tg and methods of making and using the same.