Expandable Stent Drug Loading via Segmented Pores and Shield Gas
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current stent-based drug delivery systems face challenges such as restenosis, sub-optimal release profiles, mechanical trauma, inflammation, and inability to deliver sensitive drugs due to limitations in coating thickness and material compatibility, leading to incomplete healing and potential vascular complications.
Innovation Solution
The method involves loading a beneficial agent into an expandable medical device with a plurality of holes using a dispenser and a shield gas to prevent clogging, allowing for a larger volume of drug delivery and independent release profiles through layered structures, which can include barrier, therapeutic, and cap layers, enhancing drug loading and reducing mechanical stress on the stent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If surface coating thickness is increased to improve drug release kinetics and control, then drug loading capacity increases, but stent wall thickness increases causing mechanical trauma and reduced flow cross-section
Solution Approach 1:
The invention divides the stent structure into multiple segments by creating holes or pores within the stent wall, allowing drug loading in these cavities rather than requiring thick surface coatings. This segmentation enables drug delivery while preserving the thin-walled structure and avoiding mechanical trauma.
Solution Approach 2:
The invention nests drug-containing layers within holes or pores of the stent structure itself, creating a hierarchical arrangement where the stent wall contains cavities that contain drug layers. This nested configuration allows substantial drug loading capacity while maintaining the overall thin-walled geometry.
2Duration of action of moving object
If surface coating thickness is increased to allow increased drug loading, then drug delivery duration increases, but coating vulnerability to mechanical failure increases
Solution Approach 1:
By segmenting the drug delivery function into discrete holes or pores distributed throughout the stent wall, the invention avoids creating large continuous coating areas that are vulnerable to mechanical failure. Each small drug-containing cavity is mechanically more robust than a large continuous coating.
Solution Approach 2:
The invention applies different structural qualities to different regions of the stent: the bulk stent wall maintains thin-walled geometry for mechanical compliance, while localized holes or pores provide drug loading capacity. This local differentiation allows prolonged drug delivery without compromising overall coating integrity.
3Quantity of substance
If surface coating is applied to deliver beneficial agents, then drug delivery is achieved, but release kinetics control is limited due to thin coating depth
Solution Approach 1:
The invention transitions from two-dimensional surface coating to three-dimensional drug loading by creating holes or pores within the stent wall volume. This dimensional change provides additional space for drug layers while enabling better control over release kinetics through manipulation of cavity geometry, volume, and distribution.
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
This approach enables controlled and prolonged drug release, increased drug capacity, reduced mechanical trauma, and improved safety by allowing for multi-drug combinations and tailored release profiles, while minimizing inflammation and mechanical stress on the vessel wall.
Implementation Method 1
controlling a local environment surrounding a dispensing tip of the dispenser to prevent clogging of the dispenser tip by delivering a shield gas adjacent the tip
Data Source
AI summary
The present invention relates to method and apparatus for dispensing a beneficial agent into an expandable medical device. The method includes the step of placing an expandable medical device on a support and dispensing a beneficial agent into a plurality of openings in the medical device with a shield gas for controlling a local environment surrounding the dispenser.