Polymer Agent Depot for Stent Drug Delivery
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Solution Overview
Problem
Current methods for coating endovascular stents with bioactive agents are technologically demanding, costly, and limited in their ability to achieve multiple drug release profiles or high agent concentrations, often resulting in mechanical issues and undesired side effects like restenosis and thrombosis.
Innovation Solution
The development of agent depots made from polymers that can be mechanically connected to the stent, allowing for customizable, high-concentration, and multiple-agent delivery through strategically positioned sleeves or clips, independent of the stent material, enabling flexible and targeted drug therapy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If coating systems are applied directly to the stent surface using conventional methods (rotation pulverization, immersion, spraying), then the stent can be coated with bioactive agents, but the process becomes technologically demanding, costly, and time-consuming
Solution Approach 1:
The coating system is divided into separate functional layers: a polymer matrix layer containing the bioactive agent(s) and a separate carrier layer (such as a sleeve or clip) that mechanically attaches to the stent. This segmentation allows the agent-loaded polymer to be manufactured independently and then attached to the stent, simplifying the overall process while enabling high agent concentrations in the polymer matrix without complex coating equipment
Solution Approach 2:
The polymer matrix is pre-formed with the bioactive agent incorporated before attachment to the stent. This preliminary preparation of the agent-containing polymer structure allows for controlled drug loading and simplifies the final attachment step to the stent, avoiding the need for complex in-situ coating processes
2Quantity of substance
If high concentrations of bioactive agents are incorporated into the coating, then therapeutic efficacy is improved, but mechanical issues and undesired side effects (restenosis, thrombosis) increase
Solution Approach 1:
The bioactive agent is concentrated locally within the polymer matrix depot rather than being uniformly distributed across the stent surface. This localized concentration allows high agent content in the depot to be delivered to the tissue over time, while the stent structure itself remains mechanically intact and does not suffer from agent-induced degradation or excessive local concentration effects
Solution Approach 2:
The coating system is designed to dynamically release the bioactive agent over time through controlled degradation of the polymer matrix or diffusion through the carrier layer. This dynamic release profile maintains therapeutic agent concentrations at the implant site while avoiding peak concentrations that could cause acute harmful effects like thrombosis or restenosis
3Adaptability or versatility
If multiple drug release profiles are attempted through conventional coating methods, then therapeutic versatility is improved, but the manufacturing process becomes more complex and costly
Solution Approach 1:
For multi-agent delivery, separate polymer matrix depots containing different bioactive agents can be manufactured independently and then attached to different locations on the stent structure. Each depot can be optimized for its specific agent and release profile, and the modular attachment process remains simple and cost-effective compared to attempting to incorporate multiple agents into a single conventional coating layer
Solution Approach 2:
Multiple agent-containing polymer matrices can be nested within or attached to the same carrier structure (such as a sleeve or clip system), allowing sequential or simultaneous release of multiple agents from a single attachment point on the stent. This nested arrangement maintains manufacturing simplicity while achieving versatile multi-drug delivery
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 simplifies the agent loading process, allows for customizable drug release profiles, reduces mechanical issues, and minimizes side effects such as restenosis and thrombosis by enabling high agent concentrations and multiple drug releases, improving therapeutic efficacy while reducing the risk of adverse reactions.
Implementation Method 1
a release of the pharmacological agent into the human or animal body occurring through gradual degradation of the carrier and/or diffusion into the surrounding tissue
Data Source
AI summary
An agent depot for mechanical connection to a surface of an endovascular implantable body, comprising one or more polymers, one or more bioactive agents, the agent depot being mechanically connectable to the implantable body by a force fit or an adhesive.