Stent Abluminal Layer Anchoring via Degradable Interface

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Solution Overview

Problem

Existing medical implants, such as stents, face issues with abluminal layer detachment and inflammation due to poor adhesion, leading to reduced effectiveness and potential harm to the treated organism.

Innovation Solution

An anchoring layer is applied in the transition area of the implant body to enhance the adhesion of the abluminal layer, which is degradable and endothelialization-friendly, promoting healing and preventing layer detachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an abluminal layer is applied to the implant body, then drug delivery capability is improved, but adhesion strength deteriorates leading to layer detachment

Engineering Contradiction:
Improvedrug delivery capabilityVSAvoidadhesion strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The coating system is divided into functionally distinct layers: a luminal coating layer for blood-contacting surface and an abluminal layer for drug delivery. This segmentation allows each layer to be optimized for its specific function while reducing interference between competing requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the implant receive different coating treatments. The abluminal surface is specifically prepared with surface modification techniques to enhance adhesion, while the luminal surface maintains its blood-compatible properties. This local differentiation resolves the adhesion conflict by applying针对性的 solutions to specific problem areas.

Inventive Principle:
Principle #3Local quality

2Reliability

If the abluminal layer is fully coated on the implant, then drug delivery effectiveness is improved, but tissue ingrowth behavior deteriorates

Engineering Contradiction:
Improvedrug delivery effectivenessVSAvoidtissue ingrowth behavior
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The coating is segmented into luminal and abluminal regions with different properties. The abluminal region uses a thinner or selectively applied coating that permits tissue ingrowth, while the luminal region provides complete coverage for systemic drug delivery. This spatial segmentation reconciles the conflicting requirements of drug delivery effectiveness and tissue integration.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The coating parameters (thickness, composition, porosity) are changed between luminal and abluminal regions. The abluminal coating has modified parameters that facilitate tissue ingrowth while maintaining drug delivery capability, demonstrating parameter optimization to resolve the contradiction between complete coverage and tissue adaptability.

Inventive Principle:
Principle #35Parameter changes

3Strength

If adhesion promoters like parylene or plasma treatment are applied, then layer adhesion is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvelayer adhesionVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The complex multi-step adhesion promotion processes (parylene coating, plasma treatment) are extracted and replaced with a simpler surface modification approach applied only where needed. This extraction of unnecessary complexity from the manufacturing process reduces steps while maintaining adhesion effectiveness.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Surface modification for adhesion enhancement is applied locally to the abluminal region rather than uniformly across the entire implant. This localized application reduces the overall manufacturing complexity by treating only the critical adhesion zones, eliminating the need for comprehensive complex processing of the entire device.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2465476B1Stent and method for producing the same
Publication Date: 2020.06.17 BIOTRONIK AG
  • EP2465476B1 patent drawingFigure 1~2
  • EP2465476B1 patent drawingFigure 3~4
  • EP2465476B1 patent drawingFigure 5~6

AI summary

The implant i.e. intra-luminal endo-prosthesis, has an abluminal layer (3) arranged on a body and consisting of a pharmaceutically active substance. The abluminal layer is fastened at an implant body in a transition region (7) using a degradable anchoring layer (5) that is arranged on the abluminal layer, where the anchoring layer partially covers the abluminal layer. An upper surface of the abluminal layer covered by the anchoring layer in the transition region constitutes less than 30 percent of an overall upper surface of the abluminal layer. An independent claim is also included for a method for operating an implant.