Implantable Filter Surface Ion Doping for Polymer Adhesion
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Solution Overview
Problem
Implantable vena cava filters face issues with endothelium growth and thrombosis due to insufficient adhesion of polymer film layers to metal basal bodies, leading to potential filter detachment during delivery and increased risk of venous blockage or pulmonary embolism recurrence.
Innovation Solution
A surface-modified layer containing doped ions, such as carbon and nitrogen ions, is applied to the metal basal body to chemically bond with the polymer film layer, enhancing adhesion and preventing detachment during delivery and implantation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a polymer film layer is applied on the surface of the metal basal body to prevent endothelium growth and thrombosis, then the bioadhesion resistance is improved, but the film easily falls off from the metal surface due to insufficient adhesion
Solution Approach 1:
A silane coupling agent layer is introduced as an intermediary between the metal basal body and the polymer film layer. The silane coupling agent contains both inorganic groups that bond with the metal surface and organic groups that bond with the polymer film, creating a strong chemical bridge that prevents film detachment during delivery and implantation while maintaining bioadhesion resistance
Solution Approach 2:
The surface structure is designed as a composite system consisting of metal basal body, silane coupling agent layer, and polymer film layer. This composite structure combines the advantages of each material: the metal provides structural strength, the silane coupling agent provides chemical bonding capability to both metal and polymer, and the polymer film provides bioadhesion resistance, achieving both strong adhesion and functional performance
2Ease of operation
If the filter is loaded into a delivery sheath and subjected to compression and friction during delivery, then the filter can be implanted through the blood vessel, but the film will separate from the basal body in large pieces due to strong extrusion and friction
Solution Approach 1:
The silane coupling agent layer is applied to the metal basal body surface before the polymer film layer is deposited. This preliminary action creates a pre-formed chemical bonding interface that is specifically designed to withstand the subsequent compression and friction forces during delivery, preventing film separation even under extreme mechanical stress
3Ease of manufacture
If the film directly covers the metal surface without sufficient binding force, then the film can be applied simply, but the film cannot be firmly attached and will easily fall off
Solution Approach 1:
The silane coupling agent serves as a mediator that chemically bonds to both the metal basal body and the polymer film layer. This intermediary layer transforms the simple physical deposition process into a chemically bonded structure, maintaining ease of manufacture while dramatically improving attachment reliability through strong chemical bonds that prevent film fall-off
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 enhanced adhesion ensures the polymer film layer remains firmly attached to the metal basal body, reducing endothelium growth and thrombosis, thereby improving the filter's performance and safety by preventing blockages and recurrence of pulmonary embolism.
Implementation Method 1
A surface-modified layer containing doped ions, such as carbon and nitrogen ions, is applied to the metal basal body to chemically bond with the polymer film layer, enhancing adhesion
Implementation Method 2
A surface-modified layer containing doped ions, such as carbon and nitrogen ions, is applied to the metal basal body
Data Source
Figure 1~2
Figure 3
AI summary
Provided are an implantable medical device (1) and preparation method thereof, and an implantable medical device preform for preparing the implantable medical device (1). The implantable medical device (1) comprises a metal basal body (21) and a polymer film layer (22) covering the surface of the metal basal body (21) and preventing endothelium growth and covering, wherein at least a part of the surface of the metal basal body (21) is provided with a surface-modified layer (211) which contains doped ions, and the metal basal body (21) is connected to the polymer film layer (22) by the doped ions. Since the metal basal body (21) may be connected to the polymer film layer (22) by the doped ions, the polymer film layer (22) is unlikely to fall off during delivery, therefore effectively preventing endothelium growth and covering in vivo.