Biodegradable stent and preparation method thereof

Abstract

The invention provides a biodegradable stent and a preparation method thereof. The biodegradable stent comprises an inner layer, a middle layer and an outer layer, the inner layer and the outer layer are made of a high molecular weight degradable polymer, and the middle layer is made of a low molecular weight degradable polymer. After the biodegradable stent is implanted into a blood vessel of a human body, the biodegradable stent has good supporting performance when not degraded in the early stage, and after the stent begins to degrade in the later stage, only middle-layer low-molecular-weight polymer fragments of a stent base body are basically left in the endothelium of a blood vessel, so that the degradation speed is higher, and the degradation time of stent residues in the later stage can be effectively shortened. Therefore, the probability of occurrence of adverse side effects or restenosis of the blood vessel is reduced.

Description

technical field [0001] The invention belongs to the technical field of biological scaffolds, in particular to a biodegradable scaffold with a three-layer structure prepared from polymers with different molecular weights and a preparation method thereof. Background technique [0002] Existing biodegradable polymer stents are made of polymer materials with a single molecular weight. After this kind of degradable stent is implanted in human blood vessels, it can support the diseased blood vessels in the early undegraded period, achieving the support effect and preventing the diseased After recovery, it will be degraded in the middle and later stages and become stent residues. The stent residues left in the vascular endothelium will cause adverse side effects in the lesion or lead to restenosis of the blood vessels. It will not return to normal until the stent matrix is ​​completely degraded. This kind of stent matrix with a single molecular weight has the same degradation rate ...

AI Technical Summary

Problems solved by technology

[0002] Existing biodegradable polymer stents are made of polymer materials with a single molecular weight. After this kind of degradable stent is implanted in human blood vessels, it can support the diseased blood vessels in the early undegraded period, achieving the support effect and preventing the diseased After recovery, it will be degraded in the middle and later stages and become stent residues. The stent residues left in the vascular endothelium will cause adverse side effects in the lesion or lead to restenosis of the blood vessels. It will not return to normal until the stent matrix is ​​completely degraded. This kind of stent matrix with a single molecular weight has the same degradation rate in the early and late stages of degradation, and the degradation rate of the stent residue is slow. Usually, we hope that the stent will degrade faster after the stent loses its support performance in the later stage of service, thereby reducing the adverse effects of blood vessels. Probability of side effects or restenosis

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