A kind of Biodegradable scaffold and preparation method thereof
Technical field
The invention belongs to technical field of medical instruments, be specifically related to a kind of Biodegradable scaffold and preparation method thereof.
Background technology
Cardiovascular and cerebrovascular disease still is first killer of China, has at least every year 3300000 compatriots to die from coronary heart disease or apoplexy.Than medicine and surgical operation, the intravascular stent interventional therapy is first-selected therapeutic scheme because its high curative effect and low-risk form.Optimal intravascular stent is at implant patient in intravital a period of time, and support makes blood vessel obtain mechanical support, and the medicine that goes out by eluting, the treatment of vascular restenosis.The i.e. slowly degraded of support afterwards, and absorbed by tissue entirely, blood vessel structure and systolic and diastolic function return to naturalness fully.The operation suture thread of polylactic acid (PLLA) surpasses 20 years in clinical use, and its security reliability is verified that fully its rational mechanical performance and degradation speed are the preferred material as Biodegradable scaffold simultaneously.
The BVS support that unique in the world business-like biodegradable intravascular stent is a U.S. Abbott.Its rack body is polylactic acid (PLLA).Up to now; Patient surplus using 3000; Clinical effectiveness shows that with respect to metal rack the Biodegradable scaffold of being processed by the PLLA material embodies huge advantage: can recover blood vessel normal contraction property and blood vessel power after (1) support is absorbed, stop the generation of vascular restenosis; (2) patient need not to take expensive duplex antiplatelet drug for a long time, and does not have the generation of secondary stent thrombosis; (3) can repeatedly get involved intervention (and after having put metal rack, the luminal space between this pathological changes is accepted once more is very limited) in same lesions; (4) patient can accept MRI or CT examination (and metal rack disturbs to MRI and CT); (5) can use the child who suffers from congenital diseases, not need frequent intervention again.
But poly-lactic acid material is not have development property under X-ray.Doctor's accurate locating support just when implementing intervene operation like this.In order to address this problem, BVS support two ends material has minute recesses, and the good platinum grain that develops under the X-ray is embedded in the groove two white particles shown in Fig. 1 lower left corner.When implementing the support operation, the doctor judges the position of support through the position of observing two ends platinum grain.But the problem that this support runs in clinical use is; Material at some patient body's inner support two ends is comparatively fast degraded; Thereby the platinum granule at two ends with regard to because its groove degraded and might dissociate in blood vessel; If get in the cerebrovascular with blood flow, will cause apoplexy, bring bigger harm (even fatal risk is arranged) to patient.Another shortcoming of this support is that supporting structure is more stiff, is not suitable in comparatively crooked blood vessel, using.
Summary of the invention
Deficiency to prior art the objective of the invention is to, and a kind of Biodegradable scaffold and preparation method thereof is provided, to improve the visuality that Biodegradable scaffold develops, the compliance and the safety of support under X-ray.
For solving the problems of the technologies described above; The technical scheme that the present invention adopts is: a kind of Biodegradable scaffold; It is characterized in that: said support is the network body that is formed by the braiding of degradation material silk; Also comprise the microcoils that is entwined with tinsel, described degradation material silk penetrates and is integrally formed with microcoils from the microcoils endoporus.
Said rack body comprises a plurality of deformable unit that surrounded by netting twine, at the two ends of said rack body and the free end of net skirt form a plurality of curved lines and turn.
Said each netting twine connects for contact slidably at cross point place, perhaps for not slidably gang up with the formula connection.
The material of described degradation material silk is polylactic acid, polyglycolic acid, polyvinyl alcohol, gather a kind of in own lactone, degradable magnesium alloy, the degradable ferroalloy.
The material of described microcoils is a kind of in pure platinum, platinum alloy, true yellow gold, gold alloy, pure tungsten, tungsten alloy, pure tantalum, the tantalum alloy.
The material of described microcoils is degradable magnesium alloy or degradable ferroalloy.
The diameter of described degradation material silk is less than the diameter of bore of microcoils.
Described microcoils is 1 or many.
A kind of method for preparing of Biodegradable scaffold is characterized in that said method for preparing may further comprise the steps:
(1) tinsel is wound in microcoils with the spring wrapping machine;
(2) the degradation material silk of length greater than microcoils, the microcoils endoporus is integrally formed after penetrating;
(3) thus the degradation material silk twined be woven into Biodegradable scaffold;
(4) support detects, and processes finished product.
The length of microcoils is 5~2000mm described in the step (1), and the diameter of bore of said microcoils is 10~1000um.
When the intravascular stent, prevent the medication coat of vascular restenosis in the step (3) at stent surface coated one deck, described medication coat is his mycin or paclitaxel of thunder.
Advantage of the present invention is:
1. microcoils is developed fine under X-ray; The doctor can be clearly seen that the total length profile of support under the X-ray in operation; And the present invention develops good under X-ray and can demonstrate the three-D profile of support; Be beneficial to very much the doctor and complete successfully related surgical, and the BVS support of Abbott only can be seen the platinum granule at two ends, so the visuality that the present invention develops under X-ray improves greatly;
Be through together 2.X the good microcoils of developing under the light is the degradation material silk of omnidistance and rack body, even the degraded earlier of the degradation material silk of some part, this microcoils can not break away from rack body yet.And clinically; Support is inserted the back vascular endothelial function will be unusual; Cause the vascular smooth muscle cell proliferation migration; Final about two months the vascular tissue of endothelialization can get up the support embedding, this moment microcoils break away from support flow into other blood vessels just cannot, therefore safety of the present invention improves greatly;
3. Biodegradable scaffold of the present invention can keep higher radial support power that axially compliance and vascular compliance are arranged again well after expansion, even in the blood vessel of bending, the card of support and blood vessel wall attaches still fine.
Description of drawings
Fig. 1 is the BVS of a U.S. Abbott Biodegradable scaffold sketch map;
Fig. 2 is a structural representation of the present invention;
Fig. 3 be rack body of the present invention not slidably gang up with the structural representation that formula connects;
Fig. 4 is the sketch map of the present invention in curved blood vessel;
Fig. 5 is the structural representation of the microcoils of platinum wire braiding among the present invention.
The specific embodiment
For further disclosing technical scheme of the present invention; Specify embodiment of the present invention below in conjunction with accompanying drawing: as shown in Figure 2; A kind of Biodegradable scaffold is the network body that is formed by 1 braiding of degradation material silk, also comprises the microcoils 2 (referring to Fig. 5) that is entwined with tinsel; The diameter of degradation material silk 1 is less than the diameter of bore of microcoils 2, and degradation material silk 1 penetrates and is integrally formed with microcoils 2 from microcoils 2 endoporus.As shown in Figure 3, rack body comprises a plurality of deformable unit that surrounded by netting twine, at the two ends of rack body and the free end of net skirt form a plurality of curved lines and turn.Each netting twine connects for contact slidably at cross point place, perhaps connect for slidably the formula of ganging up with not, Fig. 3 for not slidably gang up with the formula connection.The stent safety of this structural design improves greatly, and support can not bend (referring to Fig. 4) in curved blood vessel, and development effect improves greatly under X-ray, has very great help with the reduction operating difficulty to improving doctor's success rate of operation.
The material of degradation material silk 1 is polylactic acid, polyglycolic acid, polyvinyl alcohol, gather a kind of in own lactone, degradable magnesium alloy, the degradable ferroalloy.Wherein, polylactic acid can be hydrolyzed into lactic acid and acetic acid in vivo, and is CO through enzymes metabolism
2And H
2O is very ideal medical degradable material.
The material of microcoils 2 is a kind of in pure platinum, platinum alloy, true yellow gold, gold alloy, pure tungsten, tungsten alloy, pure tantalum, the tantalum alloy, and therefore development is fine under X-ray.The material of microcoils also can be degradation materials such as degradable magnesium alloy, degradable ferroalloy.Although the precious metal that development is mentioned more than being not so good as under the X-ray is much better than developing under the X-ray of Biodegradable material.Microcoils is 1 or many.Can be one and run through the total length support, also can be many sectional.
When if Biodegradable scaffold of the present invention is used for intravascular stent (like coronary stent blood vessel or peripheral blood vessel support), can evenly be coated with the medication coat (thunder commonly used he mycin or paclitaxel) that one deck can prevent vascular restenosis at rack surface.Before in this bracket leg implant patient blood vessel, blood vessel all is the narrow and obstruction of Zhi Yanchong, so blood vessel narrow or that stop up all passes through smash former (sometimes up to 20 atmospheric pressure) expansion before the support operation.Vascular tissue after the expansion is seriously torn, and has temporarily lost the physiological function of blood vessel itself.And this Biodegradable scaffold is discharged into the focus blood vessel sentence after, support makes blood vessel obtain mechanical support, and the medicine that goes out by eluting, the treatment of vascular restenosis.After about 6 to 8 months; The polylactic acid silk of rack body begins slow degraded; During 12 to 18 months, the most of degraded of rack body structure disappears, and is recovered fully through self physiological function of the blood vessel of resting and reorganizing more than a year this moment just; After vasomotoricity was recovered fully, support had just lost the value that exists.Absorbed by tissue entirely about 24 months at implantable intravascular.
If Biodegradable scaffold of the present invention is used for non-blood vessel when getting involved, and can be biliary tract rack, esophageal stents appear, intestinal support and trachea bracket, perhaps urinary system support.If it is fashionable to be used for mediated neurotransmission, can be the auxiliary support that discharges microcoils, perhaps treat the intracranial stent of cerebrovascular stenosis.
The method for preparing of Biodegradable scaffold of the present invention may further comprise the steps:
(1) tinsel is wound in microcoils with the spring wrapping machine, the length of microcoils is 5~2000mm, and diameter of bore is 10~1000um;
(2) the degradation material silk of length greater than microcoils, the microcoils endoporus is integrally formed after penetrating;
(3) thus the degradation material silk twined be woven into Biodegradable scaffold, when as intravascular stent, prevent his mycin or paclitaxel of medication coat thunder of vascular restenosis at stent surface coated one deck.
(4) support detects, and processes finished product.
More than, basic design of the present invention and ultimate principle have been set forth through introduction to listed embodiment.But the present invention never is limited to above-mentioned listed embodiment, and every equivalent variations, improvement and deliberately of inferior quality behavior of doing based on technical scheme of the present invention of change all should belong to protection scope of the present invention.