Polymer Tubular Material With Uniform Wall Thickness for Vascular Grafts
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Solution Overview
Problem
Existing methods for preparing artificial blood vessels face issues such as nozzle clogging, spinning discontinuity, solvent removal affecting temperature-sensitive components, uneven thickness, and stress-related collapse, making them unsuitable for vascular transplantation.
Innovation Solution
A method involving the diffusion of a polymer solution into a poor solvent to form a film, rolling the film with a mold to create a bar material, and removing the mold to obtain a tubular material without the need for complex equipment or heating, ensuring uniform and controllable wall thickness and mechanical stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If electrostatic spinning method is used to prepare tubular material, then fiber filaments can be formed, but nozzle clogging and spinning discontinuity occur
Solution Approach 1:
The patent extracts the problematic electrostatic spinning process and replaces it with a simple diffusion method where polymer solution is dropped onto a liquid surface to form films directly, eliminating the need for complex electrostatic equipment and avoiding nozzle clogging issues
Solution Approach 2:
The patent introduces a liquid surface (water or other liquid) as an intermediary medium to facilitate polymer film formation. The polymer solution diffuses onto the liquid surface forming a uniform film, which is then rolled into a tube, avoiding direct electrostatic processing issues
2Ease of manufacture
If solution casting method is used to obtain tubular material, then tubular structure can be formed, but solvent removal requires heating or freezing which affects material properties
Solution Approach 1:
The patent extracts the solvent removal step from the traditional solution casting process. Instead of heating or freezing to remove solvent, the method uses a non-solvent liquid surface where the polymer forms a film through diffusion, eliminating the need for thermal or freezing treatment
Solution Approach 2:
The patent changes the fundamental parameter of solvent removal by using a non-solvent liquid surface. The polymer solution diffuses onto the liquid surface and forms a film without requiring subsequent heating or freezing, thus avoiding temperature-sensitive component degradation
3Ease of manufacture
If dip-and-solidify method is used to prepare tubular material, then tubular form can be obtained, but top becomes thin and bottom becomes thick due to gravity
Solution Approach 1:
The patent inverts the traditional dip-and-solidify approach. Instead of dipping a mold into polymer solution and having gravity cause uneven distribution, the method drops polymer solution onto a liquid surface where diffusion creates uniform films, then rolls the film into a tube
Solution Approach 2:
The patent replaces the gravity-driven dip-and-solidify process with a diffusion-based mechanism. The polymer solution diffuses uniformly onto the liquid surface through molecular diffusion, creating even film thickness before rolling, eliminating gravity-induced unevenness
4Ease of manufacture
If film rolling method is used to obtain tubular material, then tubular structure can be formed, but uneven stress and collapse occur
Solution Approach 1:
The patent performs preliminary film formation with uniform thickness through diffusion onto a liquid surface before rolling. This preliminary uniform film structure prevents stress concentration during rolling, avoiding collapse and ensuring structural stability
Solution Approach 2:
The patent ensures homogeneity of the polymer film through diffusion onto a liquid surface, creating uniform thickness and composition throughout the film before rolling. This homogeneity prevents uneven stress distribution during tubular formation, eliminating collapse issues
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 method produces tubular materials with uniform mechanical properties suitable for artificial blood vessels, avoiding uneven stresses and collapse, and can be completed at room temperature without thermal deactivation, suitable for vascular transplantation.
Implementation Method 1
adding a polymer solution to a poor solvent to diffuse the polymer into a film on a liquid surface of the poor solvent
Implementation Method 2
a solvent in the polymer solution is dissolved in the poor solvent
Data Source
AI summary
Provided is a preparation method for a tube. The method comprises the following steps: a) adding a polymer solution into a poor solvent, such that the polymer diffuses on the liquid level of the poor solvent, so as to obtain a polymer film, wherein the solvent in the polymer solution is dissolved in the poor solvent; b) curling the polymer film on the liquid level of the poor solvent by using a mold to obtain a bar; and c) removing the mold to obtain a tube. The present invention further provides the use of the above tubular as an artificial tubular tissue.