Non-Polymeric Tacrolimus Stent Coating for Stable Delayed Elution
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Solution Overview
Problem
Existing drug-eluting stents face challenges with drug binding stability and polymer-related issues like inflammation and late thrombosis, requiring a method to strongly and stably bind tacrolimus onto a stent without using polymers and improving drug elution characteristics.
Innovation Solution
A manufacturing method involving forming a nitrogen-doped titanium oxide layer on a stent, followed by femtosecond laser processing, and electrospinning a tacrolimus drug solution onto the treated surface without using polymers, to enhance drug binding and elution properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a polymer coating is used to bind drug onto stent, then drug binding is achieved, but inflammation and late thrombosis occur
Solution Approach 1:
The patent removes the polymer component entirely from the drug delivery system. Instead of using a polymer coating to bind and release the drug, the invention directly binds tacrolimus to the stent surface through chemical functionalization, extracting the harmful polymer element while maintaining drug delivery functionality.
Solution Approach 2:
The patent introduces a silane coupling agent as an intermediary substance that facilitates drug binding to the stent surface. The silane forms a bridge between the stent substrate and the tacrolimus drug molecules, enabling stable drug attachment without requiring polymer materials.
2Object-affected harmful factors
If electrospinning is used without polymer, then late thrombosis is avoided, but drug binding strength is insufficient
Solution Approach 1:
The patent performs preliminary chemical modification of the stent surface by forming a silane coupling layer before drug application. This preliminary action creates reactive functional groups on the stent surface that strongly bind tacrolimus molecules, ensuring adequate drug binding strength without requiring polymer materials.
3Reliability
If surface-binding functional groups are introduced to bind drug, then drug binding is improved, but manufacturing complexity increases
Solution Approach 1:
The patent combines multiple functions into a single silane coupling agent that simultaneously provides surface modification, creates binding sites, and facilitates drug attachment. This merging of functions reduces the number of separate manufacturing steps required compared to introducing separate surface-binding functional groups.
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 method allows for strong and stable drug binding and improved drug elution characteristics, including increased total drug elution amount and better drug elution delay, without the need for surface-binding functional groups or polymers.
Implementation Method 1
irradiating the titanium oxide layer with a femtosecond pulse laser to perform femtosecond laser processing
Implementation Method 2
electrospinning an electrospinning mixed solution including a tacrolimus drug and a solvent on the femtosecond laser-processed titanium oxide layer
Data Source
AI summary
A tacrolimus drug-eluting stent manufacturing method according to the present invention enables a tacrolimus drug to be strongly and stably bound onto a stent, while also not necessarily involving a separate step of introducing a surface-binding functional group for the binding of a drug onto a stent and a step of introducing, into the drug, a functional group capable of binding to the surface-binding functional group, and a tacrolimus drug-eluting stent manufactured by the manufacturing method has a greater total drug elution amount and has a more excellent delayed drug-elution property.