Bioabsorbable Stent with Amorphous Particle Reinforcement
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Solution Overview
Problem
Current stents for preventing organic passageway collapse, such as airways and veins, face issues like migration, fracture due to inadequate mechanical properties, granulation tissue formation, and difficulty in removal, especially in cases of malignant or benign obstructions, where metallic stents are permanent and cause damage upon removal, and silicone stents require rigid bronchoscopy and are poorly tolerated.
Innovation Solution
A stent made from biocompatible and bioabsorbable materials, reinforced with amorphous particles like magnesium phosphate, and coated with nanocapsules containing therapeutic agents, designed to improve mechanical properties, prevent calcification, and facilitate controlled drug release, allowing for temporary placement and absorption by the body.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metallic stents are used to prevent collapse of organic conduits, then mechanical strength is improved, but removal becomes difficult and causes damage
Solution Approach 1:
The patent applies parameter changes by transitioning from permanent metallic materials to bioabsorbable materials whose mechanical properties and degradation characteristics can be controlled. The stent is designed with specific tensile strength (≥50 MPa) and elongation (≥10%) parameters that degrade over time, allowing initial mechanical support followed by gradual absorption, thus resolving the contradiction between strength and ease of removal
Solution Approach 2:
The patent employs composite materials combining bioabsorbable polymer matrix with reinforcing particles (hydroxyapatite, tricalcium phosphate, or biocrystal) to achieve both adequate mechanical strength for stent support and controlled degradability for eventual absorption. This composite structure provides the necessary strength while maintaining the ability to be removed or absorbed without damage
2Strength
If stent material strength is increased to prevent fracture, then mechanical reliability is improved, but bioabsorbability may be reduced
Solution Approach 1:
The patent controls the degradation rate by adjusting material composition parameters and molecular weight of the bioabsorbable polymer. The stent is designed with specific tensile strength (≥50 MPa) and elongation (≥10%) that are maintained during the required functional period, then gradually degraded. This parameter control allows tuning of both strength and absorption duration to match clinical needs
Solution Approach 2:
The composite structure with bioabsorbable polymer matrix and inorganic reinforcing particles allows independent optimization of strength and degradation. The polymer matrix provides bioabsorbability while the particulate reinforcement (hydroxyapatite, tricalcium phosphate, or biocrystal) enhances mechanical strength without significantly affecting the degradation rate, thus resolving the contradiction between strength and bioabsorbability duration
3Strength
If stents are designed for permanent placement, then mechanical support is maintained, but migration and granulation tissue formation increase
Solution Approach 1:
The patent employs parameter changes by designing the stent with controlled degradation parameters. The stent maintains its mechanical support function (tensile strength ≥50 MPa, elongation ≥10%) during the critical healing period, then gradually degrades and is absorbed by the body. This temporal parameter change eliminates the long-term presence of foreign material, thereby preventing migration and granulation tissue formation while maintaining necessary mechanical support
Solution Approach 2:
The patent applies the principle of temporary implants by using bioabsorbable materials that fulfill their mechanical support function for a limited period and then are naturally absorbed. This disposable approach eliminates the need for permanent foreign material in the body, preventing long-term complications like migration and granulation tissue, while still providing adequate mechanical support during the critical healing phase
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 stent provides enhanced mechanical resistance, prevents collapse of organic conduits, and allows for controlled drug delivery, reducing the risk of granulation tissue formation and easy absorption, thus addressing the limitations of existing stents.
Implementation Method 1
A stent (1) comprising a material (10) selected from a biocompatible material and a bioabsorbable material, or a mixture thereof; and particles (11) selected from biocompatible amorphous particles, bioabsorbable amorphous particles, and combinations thereof
Implementation Method 2
A stent made from biocompatible and bioabsorbable materials, reinforced with amorphous particles like magnesium phosphate, and coated with nanocapsules containing therapeutic agents, designed to improve mechanical properties, prevent calcification, and facilitate controlled drug release, allowing for temporary placement and absorption by the body
Implementation Method 3
coated with nanocapsules containing therapeutic agents, designed to improve mechanical properties, prevent calcification, and facilitate controlled drug release
Data Source
AI summary
The present disclosure relates to several embodiments of a stent. For example, the present disclosure describes a stent comprising a material selected from a biocompatible material, a bioabsorbable material, and combinations thereof; and particles selected from biocompatible amorphous particles, bioabsorbable amorphous particles, and combinations thereof.The stent may also include a coating of a material selected from a biocompatible material, a bioabsorbable material, and combinations thereof; nanocapsules and a therapeutic agent encapsulated in the nanocapsules.The stent disclosed herein enables the walls of an airway or blood vessel to be supported, while there is controlled delivery of the therapeutic agent to said airway or blood vessel to prevent, cure, alleviate or repair symptoms of disease.