Tissue-Coated Stent with Intentional Defects for Rapid Reendothelialization

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Solution Overview

Problem

Medical articles, such as stents, with bare metal surfaces often cause endothelial dysfunction and thrombosis due to disruption of the endothelium, leading to rethrombosis and restenosis, as they lack a biocompatible surface for rapid reendothelialization.

Innovation Solution

A tissue-engineered stent is created by embedding a nitinol stent within a biomaterial scaffold containing biological cells, which is converted into a tissue layer through culturing, and then decellularized to form a tissue-coated stent with intentional defects that allow tissue contraction and expansion without detachment, providing a biocompatible surface for rapid reendothelialization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a bare metal surface is used for medical articles, then the article can be introduced into vasculature to keep vessels open, but the endothelium is disrupted and thrombosis occurs

Engineering Contradiction:
Improvevessel patencyVSAvoidendothelial dysfunction
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The stent is pre-coated with a tissue layer containing living cells before implantation. This preliminary action of seeding the stent with a biological coating allows rapid reendothelialization upon implantation, preventing endothelial dysfunction and thrombosis that would otherwise occur with bare metal surfaces

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention combines metal stent structure with a biological tissue coating to create a composite medical device. The metal provides mechanical support while the tissue layer provides biocompatibility and promotes endothelialization, resolving the contradiction between structural integrity and biological compatibility

Inventive Principle:
Principle #40Composite materials

2Reliability

If a tissue layer is applied to the article surface, then reendothelialization is accelerated and biocompatibility is improved, but the tissue may detach during contraction and expansion

Engineering Contradiction:
Improvereendothelialization rateVSAvoidtissue attachment
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The stent structure incorporates porous or mesh-like features that allow tissue ingrowth through the coating. This porous architecture mechanically interlocks the tissue layer with the stent surface, preventing detachment during vessel contraction and expansion while maintaining the biocompatible surface for rapid reendothelialization

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The tissue coating is designed with dynamic properties that allow it to flex and move with the vessel wall during contraction and expansion. The coating incorporates flexible polymers or elastomeric materials that maintain tissue-stent attachment through mechanical deformation without detachment

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3542832B1Tissue-coated articles
Publication Date: 2023.05.24 MEDTRONIC VASCULAR INC
  • EP3542832B1 patent drawingFigure 1A~1C
  • EP3542832B1 patent drawingFigure 2A~2F
  • EP3542832B1 patent drawingFigure 3A~3E

AI summary

Example articles coated with tissue layers and techniques for forming articles with tissue layers. An example article may include a tubular frame extending along a longitudinal axis. The tubular frame includes a plurality of struts joined at apices to define a plurality of cells including a group of struts. The example article includes a tissue layer coating each strut and extending across each cell. The tissue layer defines a plurality of defects, each cell including a respective defect.