Implantable Devices With Porous Zinc Layers for Controlled Release
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing implantable devices face challenges in inhibiting smooth muscle cell proliferation and preventing zinc toxicity, leading to restenosis and tissue necrosis due to uncontrolled release of zinc ions.
Innovation Solution
An implantable device with a zinc-containing layer having a specific mass-to-surface area ratio and porosity, combined with a polymer layer, controls the release of zinc ions to inhibit smooth muscle cell proliferation while avoiding toxic concentrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If zinc-containing substances are released from the implantable device to inhibit smooth muscle cell proliferation, then the lumen stenosis rate is reduced, but the zinc ions may accumulate to toxic concentrations and cause tissue ulceration or necrosis
Solution Approach 1:
The patent employs a porous coating layer on the implantable device that allows controlled release of zinc ions. The porous structure provides channels for zinc ion diffusion while maintaining a barrier that prevents excessive accumulation in surrounding tissues, thus achieving both anti-proliferation effect and tissue safety.
Solution Approach 2:
The patent modifies the release parameters of zinc ions by controlling the coating composition, porosity, and thickness. By adjusting these parameters, the release rate of zinc ions is optimized to maintain therapeutic concentrations for inhibiting smooth muscle cell proliferation while preventing toxic accumulation that would cause tissue damage.
2Reliability
If a zinc-containing layer is applied to the implantable device to control zinc ion release, then smooth muscle cell proliferation is inhibited, but the device complexity increases
Solution Approach 1:
The patent uses composite coating materials that combine zinc-containing compounds with biocompatible polymers or ceramics. This composite structure enables controlled zinc ion release while maintaining device functionality and simplifying the overall design compared to more complex multi-layered or actively controlled release systems.
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 device effectively inhibits smooth muscle cell proliferation and prevents tissue necrosis by maintaining zinc concentrations within safe limits, ensuring the safety and efficacy of the implant.
Implementation Method 1
during the corrosion of a zinc-containing implantable device in an implanted body, zinc ions and other zinc-containing substances released from the implantable device
Data Source
AI summary
An implantable device including a matrix and a zinc-containing layer at least partially covering the substrate. The zinc-containing layer includes a zinc compound. The ratio of the mass of the zinc element in the zinc-containing layer to the surface area of the implantable device is 0.1-200 μg/mm2. The average porosity of the zinc-containing layer is 30% or less. By matching the ratio of the mass of zinc in the zinc-containing layer to the surface area of the implantable device with the average porosity of the zinc-containing layer, the release rate of zinc is controlled within a reasonable range so that the rate of formation of the zinc-containing substance is controlled such that the concentration of the zinc-containing substance accumulated in the tissue is higher than the concentration which inhibits the proliferation of smooth muscle cells, and is always lower than the toxic concentration which causes cell death.