Degradable vascular stent, and manufacturing method thereof

A technology for vascular stents and degrading polymers, used in stents, medical science, surgery, etc., can solve the problems of poor mechanical properties of polymer networks, insufficiently compact stents, unstable stent performance, etc., to reduce mechanical relaxation behavior, reduce The effect of retraction

Active Publication Date: 2014-04-09
上海发微医用材料有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] However, the commonly used high molecular polymer materials generally have the following defects: insufficient mechanical strength, resulting in poor radial compression resistance of the stent, easy fracture of the crimping grip, and mechanical relaxation behavior of the material, resulting in unstable performance of the stent, and the radial support force varies with time. With the decline of time, short shelf life and other issues
However, the mechanical properties of the polymer network are very poor, such as the E-modulus is only 0.5-50MPa, and it has a mechanical relaxation behavior, that is, under a fixed temperature and deformation, the stress inside the polymer gradually decays with time.
In order to reduce the weakness of the polymer material, the wall thickness of the polymer stent is much thicker than that of the metal stent, so that the size of the stent is not compact enough; and the degradation rate of the stent cannot be adjusted according to the healing time of the vascular lesion

Method used

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  • Degradable vascular stent, and manufacturing method thereof
  • Degradable vascular stent, and manufacturing method thereof
  • Degradable vascular stent, and manufacturing method thereof

Examples

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no. 1 example

[0046] The degradable vascular stent according to the present invention is formed by laser cutting a polymer tube with a three-dimensional cross-linked network structure. In the following, two examples will be combined to illustrate the process of preparing polymer pipes with a three-dimensional cross-linked network structure.

example 1

[0048] Synthesis of Star Polylactic Acid Copolymer Prepolymer and Introduction of Crosslinkable Groups

[0049] Referring to Figure 1(a), a 3-liter glass reactor was vacuum-dried at 80°C for 1 hour before polymerization, and 2100 g of L-lactide, 370 g of glycolide and 22 g (0.16 mol) of 1,2,6- Hexatriol was added into the reaction kettle, and after repeated vacuum and argon gas deoxygenation processes, stannous octoate was added, and the reaction was carried out at 145°C. When the number-average molecular weight of the star-shaped polylactic acid copolymer prepolymer meets the requirements of the experimental design, add 114 grams (0.741 mol) of methacrylic anhydride and 0.75 grams of free radical inhibitors such as p-hydroxyanisole to form cross-linked Star polymers with linked reactions (see Fig. 1(b)). After the reaction, the temperature was lowered to 60°C, 5 liters of ethyl acetate was added to the reactor to dissolve the prepolymer, and then slowly poured into the mixed...

example 2

[0063] As shown in Figure 2(a), firstly, cyclic monomers or cyclic comonomers, such as L-lactide and ε-caprolactone (L-LA / ε-CL molar ratio of 95 / 5) Synthesize star-shaped degradable polymer copolymer as the first prepolymer.

[0064]The second step is to synthesize the cross-linking agent, see Figure 2(b) for details. Use the same method as the first step to synthesize the second prepolymer of star-shaped copolymers with hydroxyl groups, such as L-lactide and ε-caprolactone (L-LA / ε-CL molar ratio is 95 / 5 ), but different from the first prepolymer prepared in the first step, the number average molecular weight of the second prepolymer is controlled between 500 and 100,000. Then by polycondensation, in the molecules of the second prepolymer (here including 2, 3 or 4 arm linear or star polymer, but preferably with 3 or 4 arm star polymer) isocyanate is introduced, and the remaining isocyanate is removed by polymer precipitation washing to ensure that there is no isocyanate resi...

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Abstract

The invention belongs to the field of medical instrument, and specifically provides a degradable vascular stent which is prepared via laser cutting of high molecular tubes, wherein the high molecular tubes possess three-dimensional crosslinked network structures. The invention also provides a method used for preparing the degradable vascular stent. The degradable vascular stent is high enough in mechanical strength, and is high in elasticity modulus at body temperature, so that the degradable vascular stent can be prepared with a compact size, is capable of providing enough radial support force against vascular walls, is capable of avoiding retraction in blood vessels as far as possible, and is capable of controlling degradation rate of the degradable vascular stent according to recovering time of vascular diseases.

Description

technical field [0001] The invention relates to the field of medical instruments. More specifically, the present invention relates to a degradable vascular stent and a manufacturing method thereof. Background technique [0002] Currently, the stents used in the treatment of postoperative vascular restenosis usually include metal stents, drug-coated metal stents and biodegradable stents. Although metal stent-related technologies have made continuous progress and solved the elastic recoil of blood vessels after PTCA, they still cannot solve the problems of intimal hyperplasia caused by intimal injury and metal foreign bodies. Drug-coated metal stents can inhibit intimal hyperplasia to a certain extent and reduce the occurrence rate of restenosis, but stimulation by metal foreign bodies is unavoidable, requiring long-term administration of antiplatelet drugs. In addition, metal stents prevent beneficial late vessel remodeling phenomena. [0003] The occurrence of vascular re...

Claims

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Application Information

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IPC IPC(8): A61L31/06A61F2/915
Inventor 姜洪焱罗七一
Owner 上海发微医用材料有限公司
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