Bioabsorbable Stent Coatings for Flexible Deployment
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Solution Overview
Problem
Current drug-eluting stents face challenges such as residual physical, chemical, and therapeutic legacy in the vessel, thickness issues for deployment flexibility, access to small vessels, and minimized vessel wall intrusion, which affect their efficacy and safety over time.
Innovation Solution
A drug-eluting stent design featuring a laminate coating with a pharmaceutical agent layer composed of crystalline particles free of polymer, where bioabsorbable polymers are used to minimize intrusion and enhance deployment flexibility, and a controlled elution profile to reduce residual effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a drug-eluting stent is designed with sufficient thickness to maintain structural integrity and deliver therapeutic agents, then therapeutic effectiveness is improved, but deployment flexibility and access to small vessels deteriorate
Solution Approach 1:
The stent coating is segmented into multiple functional layers: a first bioabsorbable polymer layer for structural support and drug delivery, a pharmaceutical agent layer for therapeutic effect, and a second bioabsorbable polymer layer for protection. This segmentation allows each layer to be optimized independently for its specific function while collectively achieving both therapeutic effectiveness and flexibility.
Solution Approach 2:
The stent employs thin film coatings of bioabsorbable polymers instead of thick rigid structures. These thin films provide the necessary therapeutic agent delivery while maintaining stent flexibility for deployment in small vessels and tortuous lesions, directly addressing the contradiction between thickness and flexibility.
2Strength
If a drug-eluting stent uses conventional polymer-coated designs, then structural integrity is maintained, but residual physical and chemical legacy in the vessel increases
Solution Approach 1:
The patent changes the chemical parameters of the polymer coating by using bioabsorbable polymers that degrade into non-toxic byproducts (CO2, H2O, lactic acid) that are naturally metabolized by the body. This parameter change from conventional non-degradable polymers to bioabsorbable polymers eliminates residual chemical legacy while maintaining structural integrity during the required therapeutic period.
Solution Approach 2:
The bioabsorbable polymer layers are designed to degrade and be absorbed by the body over time (6-18 months), discarding the structural support function once the vessel has healed and the therapeutic effect has been achieved. This eliminates long-term residual legacy while providing necessary structural support during the critical healing period.
3Quantity of substance
If the stent coating thickness is increased to enhance drug delivery capacity, then therapeutic effect is improved, but intrusion into the vessel wall and blood increases
Solution Approach 1:
The pharmaceutical agent layer is positioned locally between the first and second polymer layers, concentrating the therapeutic agents at the interface with the vessel wall. This local concentration strategy achieves high drug delivery capacity to the vessel wall without requiring increased overall coating thickness, thereby minimizing intrusion into the vessel wall and blood.
4Reliability
If a stent framework with thick coating is used to ensure adequate drug elution, then therapeutic effectiveness is improved, but access to difficult lesions and small vessels deteriorates
Solution Approach 1:
The stent employs thin film coatings of bioabsorbable polymers instead of thick rigid structures. These thin films provide the necessary therapeutic agent delivery while maintaining stent flexibility for deployment in small vessels and tortuous lesions, directly addressing the contradiction between thickness and flexibility.
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 stent achieves minimal residual impact, improved deployment flexibility, and enhanced access to small vessels with a controlled drug release, reducing inflammation and thrombosis risks while maintaining therapeutic effectiveness.
Implementation Method 1
a controlled elution profile to reduce residual effects
Implementation Method 2
crystal particles of said pharmaceutical agent and said three dimensional physical space is free of polymer
Implementation Method 3
bioabsorbable polymers are used to minimize intrusion and enhance deployment flexibility
Implementation Method 4
minimal physical, chemical and therapeutic legacy in the vessel after a proscribed period of time
Data Source
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AI summary
Provided herein is a device comprising: a. stent; b. a plurality of layers on said stent framework to form said device; wherein at least one of said layers comprises a bioabsorbable polymer and at least one of said layers comprises one or more active agents; wherein at least part of the active agent is in crystalline form.