CN108201474A - Valvuloplasty ring - Google Patents

Abstract

The invention discloses a kind of valvuloplasty rings, belong to the field of medical instrument technology.The valvuloplasty ring includes metal inner tube layer, is coated on the layer of silica gel middle layer of the metal tube inner layer outer surface and is coated on the woven dacron outer layer of the layer of silica gel middle layer outer surface, and the outer surface of the woven dacron outer layer is coated with the Parylene coating of 0.01 100 μ m-thicks.The Parylene coating material that the present invention is used with woven dacron combination power is strong and own biological compatibility is good, by the thickness for controlling Parylene coating, so that the valvuloplasty ring with polyxylene coating being prepared is while inflammatory reaction is reduced, and being capable of effective antithrombotic.

Description

heart annuloplasty ring

technical field

The invention relates to the technical field of medical devices, in particular to a heart valve forming ring, the surface of which is coated with a coating capable of reducing inflammation and resisting thrombus.

Background technique

For valvular insufficiency, regurgitation, the common treatment is valvuloplasty. In order to maintain the long-term therapeutic effect, after valvuloplasty, the surgeon often implants an artificial valvuloplasty ring at the position of the valve annulus to ensure the good shaping of the native valve annulus and prevent further expansion of the valve annulus in order to maintain the long-term therapeutic effect. maintain the therapeutic effect.

The existing artificial annuloplasty ring mainly has a three-layer structure, the innermost layer is metal or polymer material support body, the middle layer is silica gel, and the outermost layer is polyester polyester cloth; the role of polyester cloth is to help tissue Ingrown to stabilize the prosthetic annulus and reduce the risk of dehiscence.

Although polyester polyester cloth itself has a certain biocompatibility, when the biomedical material made of polyester fiber is implanted into the human body and soaked in the blood for a long time, its blood compatibility cannot fully meet the requirements, and there will be coagulation and thrombus formation. And the risk of severe inflammation will directly affect the service life of the material and endanger the safety of patients. At present, the above-mentioned problems have not been completely resolved.

Contents of the invention

Based on this, it is necessary to provide a heart valvuloplasty ring to address the above defects. The forming ring is coated with a Parylene coating on the outer surface of the polyester cloth outer layer, which is anti-thrombotic while reducing inflammation.

The present invention provides a heart valvuloplasty ring, which comprises an inner layer of a metal tube, an intermediate layer of a silica gel layer covering the outer surface of the inner layer of the metal tube, and an outer layer of polyester cloth covering the outer surface of the intermediate layer of the silica gel layer; The outer surface of the polyester cloth outer layer is coated with a 0.01-100 μm thick parylene (Parylene) coating.

In one embodiment, the parylene is parylene C or parylene N.

In one embodiment, the parylene coating has a thickness of 0.1-50 μm.

In one embodiment, when the parylene is parylene C, the thickness of the parylene coating is 0.5-30 μm.

In one embodiment, when the parylene is parylene C, the thickness of the parylene coating is 1-20 μm.

In one embodiment, when the parylene is parylene N, the thickness of the parylene coating is 0.5-35 μm.

In one embodiment, when the parylene is parylene N, the thickness of the parylene coating is 1-25 μm.

In one embodiment, the parylene coating has a thickness of 1-10 μm.

In one embodiment, the metal tube is a nickel-titanium cut tube.

The present invention adopts a parylene coating material with strong binding force with polyester cloth and good self-biocompatibility, and by controlling the thickness of the parylene coating, the prepared heart with the parylene coating The valvuloplasty ring can effectively antithrombotic while reducing the inflammatory response.

Description of drawings

Fig. 1 is the structural representation of heart annuloplasty ring in the prior art;

Fig. 2 is the schematic structural view of the cardiac valvuloplasty ring coated with Parylene C coating in Example 1;

Fig. 3 is the histopathological result figure that the heart valvuloplasty ring of embodiment 3 is implanted into pig's inferior vena cava 7 days;

Fig. 4 is the histopathological result figure that the heart valvuloplasty ring of embodiment 4 is implanted in pig's inferior vena cava 7 days;

Fig. 5 is the histopathological result figure that the heart valvuloplasty ring of embodiment 5 is implanted in pig's inferior vena cava 7 days;

Fig. 6 is a histopathological result figure taken out after 7 days after implanting the heart valvuloplasty ring of Example 10 into the pig's inferior vena cava;

Fig. 7 is a histopathological result diagram taken out 7 days after the heart valvuloplasty ring of Example 11 was implanted into the pig's inferior vena cava;

Fig. 8 is a diagram of the histopathological results after implanting the heart valvuloplasty ring of Example 12 into the pig's inferior vena cava 7 days;

Fig. 9 is a diagram of the histopathological results after implanting the heart valvuloplasty ring of Comparative Example 1 into the pig's inferior vena cava 7 days;

Fig. 10 is a graph showing histopathological results taken out 7 days after the heart valvuloplasty ring of Comparative Example 2 was implanted into the pig's inferior vena cava.

Detailed ways

In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation manners of the present invention will now be described in detail with reference to the accompanying drawings.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the invention. The terms used herein in the specification are for the purpose of describing specific embodiments only, and are not intended to limit the present invention.

The structure of a heart valvuloplasty ring commonly used at home and abroad is shown in Figure 1. The valvuloplasty ring is composed of a metal ring, a suturable ring and an interlining. The material of the metal ring is Ti-6Al-4V, the ring edge is made of a layer of silicone rubber, and its outer surface is covered with polyester interlining.

The surface modification method of traditional polyester materials is to construct a single-function biomimetic coating on the surface of polyester materials, which often only has a single function of anti-thrombosis or promoting endothelialization or reducing inflammation. It is difficult to ensure that the coating and polyester cloth Combined with multi-function. In the process of coating the surface of the polyester cloth, it is necessary to ensure the bonding force between the coating and the polyester cloth, and to ensure that the valvuloplasty ring can reduce inflammation and achieve antithrombosis after coating the coating.

Parylene can be divided into Parylene C (Parylene C, one chlorine substitution), Parylene D (Parylene D, dichlorination substitution), Parylene N (Parylene N, unsubstituted) And parylene HT (ParyleneHT, fluoride), mostly prepared by chemical vapor deposition (CVD), the whole preparation process is a gaseous reaction under vacuum conditions, so a very uniform coating can be obtained. The gas phase deposition process of Parylene is generally divided into three steps: (1) sublimation of solid raw materials into gaseous raw materials at 120°C in a vacuum state; (2) cracking of gaseous raw materials in step (1) into active single (3) Deposit and polymerize the active monomer of step (2) at 25°C. The active monomer first diffuses on the surface of the workpiece. When the active monomer is adsorbed to the surface of the workpiece, it starts to polymerize and crystallize, and directly forms a solid. The thickness of the coating is controlled by the deposition time. The general deposition speed is about 1μm/60min. Both Parylene and polyester fabric contain benzene ring structure, and the van der Waals force between them is strong, which ensures the connection strength between Parylene coating and polyester fabric.

Uneven coating, such as bubbles, impurities or irregularities, will easily affect the connection strength between the coating and the polyester cloth. In the above process, there is no liquid phase, which overcomes the uneven thickness and common defects in the coating, and the coating is evenly coated, which also ensures the connection strength between the coating and the substrate.

Parylene C is a monochlorine substitute of Parylene N, which has stronger polarity and greater binding force with polyester cloth than Parylene N. When Parylene C is used to coat the coating, too thick coating will harden the surface of the polyester cloth. Therefore, the applicable range of Parylene C is smaller than that of Parylene N.

The thickness of the parylene coating is 0.01-100 μm, preferably 0.1-50 μm. If the coating is too thin, its binding force with the polyester cloth is weak, and the coating is easy to fall off; if the coating is too thick, it is easy to harden the polyester cloth. Controlling the thickness of the parylene coating at 0.01-100 μm can ensure the effect of the coating, so that the coating can play an antithrombotic effect while reducing inflammation.

Example 1

Please refer to Fig. 2, a kind of heart valvuloplasty ring, comprises nickel-titanium cutting tube inner layer 1, is coated on the outer surface of nickel-titanium cutting tube inner layer 1 outer surface with the silicone intermediate layer 2 with suture edge 5 and is coated on the silicone intermediate layer 2 The polyester cloth outer layer 3 on the outer surface, the outer surface of the polyester cloth outer layer 3 is uniformly coated with a 0.01 μm thick Parylene C coating 4 .

The preparation method of Parylene C coating 4 comprises the steps: (1) in vacuum state, 120 DEG C, the solid raw material of the p-xylene ring dimer of monochlorine substitution is sublimated into gaseous raw material; (2) in 680 DEG C, step (1 ) gaseous raw material is cracked into a chlorine-substituted monomer double radical with reactive characteristics; (3) the monomer double radical of step (2) is deposited and polymerized at 25°C for 36s to obtain Parylene C coating 4; wherein the coating The thickness of the layer is controlled by the deposition time, and the general deposition rate is 1μm/60min. Its reaction is shown in formula 1.

Example 2

The heart valvuloplasty ring of this example has a similar structure to the heart valvuloplasty ring of Example 1, the difference being that the outer surface of the polyester cloth outer layer is evenly coated with a 0.1 μm thick Parylene C coating.

The preparation method of the Parylene C coating is similar to the preparation method of the Parylene C coating in Example 1, except that the deposition time is 6 minutes.

Example 3

The heart valvuloplasty ring of this example has a similar structure to the heart valvuloplasty ring of Example 1, the difference being that the outer surface of the polyester cloth outer layer is evenly coated with a 1 μm thick Parylene C coating.

The preparation method of the Parylene C coating is similar to the preparation method of the Parylene C coating in Example 1, except that the deposition time is 60 min.

Example 4

The heart valvuloplasty ring of this example has a similar structure to the heart valvuloplasty ring of Example 1, the difference being that the outer surface of the polyester cloth outer layer is evenly coated with a 10 μm thick Parylene C coating.

The preparation method of the Parylene C coating is similar to the preparation method of the Parylene C coating in Example 1, except that the deposition time is 600 min.

Example 5

The heart valvuloplasty ring of this example has a similar structure to the heart valvuloplasty ring of Example 1, the difference being that the outer surface of the polyester cloth outer layer is evenly coated with a 20 μm thick Parylene C coating.

The preparation method of the Parylene C coating is similar to the preparation method of the Parylene C coating in Example 1, except that the deposition time is 1200 min.

Example 6

The heart valvuloplasty ring of this example has a similar structure to the heart valvuloplasty ring of Example 1, the difference being that the outer surface of the polyester cloth outer layer is evenly coated with a 50 μm thick Parylene C coating.

The preparation method of the Parylene C coating is similar to the preparation method of the Parylene C coating in Example 1, except that the deposition time is 3000 min.

Example 7

The heart valvuloplasty ring of this example has a similar structure to the heart valvuloplasty ring of Example 1, the difference being that the outer surface of the polyester cloth outer layer is evenly coated with a 100 μm thick Parylene C coating.

The preparation method of the Parylene C coating is similar to the preparation method of the Parylene C coating in Example 1, except that the deposition time is 6000 min.

Example 8

The heart valvuloplasty ring of this example has a similar structure to the heart valvuloplasty ring of Example 1, the difference being that the outer surface of the polyester cloth outer layer is evenly coated with a 0.01 μm thick Parylene N coating.

The preparation method of the Parylene N coating comprises the following steps: (1) sublimating the solid raw material of the p-xylene ring dimer into a gaseous raw material at 120° C. in a vacuum state; (2) cracking the gaseous raw material in step (1) at 680° C. It is an active monomer double radical with reactive characteristics; (3) deposit the active monomer double radical of step (2) at 25°C for 36s and polymerize to obtain a Parylene N coating; wherein the thickness of the coating is controlled by the deposition time , the general deposition rate is 1μm/60min. Its reaction is shown in formula 2.

Example 9

The heart valvuloplasty ring of this example has a similar structure to the heart valvuloplasty ring of Example 1, the difference being that the outer surface of the polyester cloth outer layer is evenly coated with a 0.1 μm thick Parylene N coating.

The preparation method of the Parylene N coating is similar to the preparation method of the Parylene N coating in Example 8, except that the deposition time is 6 minutes.

Example 10

The heart valvuloplasty ring of this example has a similar structure to the heart valvuloplasty ring of Example 1, the difference being that the outer surface of the polyester cloth outer layer is evenly coated with a 1 μm thick Parylene N coating.

The preparation method of the Parylene N coating is similar to the preparation method of the Parylene N coating in Example 8, except that the deposition time is 60 min.

Example 11

The heart valvuloplasty ring of this example has a similar structure to the heart valvuloplasty ring of Example 1, the difference being that the outer surface of the polyester cloth outer layer is evenly coated with a 10 μm thick Parylene N coating.

The preparation method of the Parylene N coating is similar to the preparation method of the Parylene N coating in Example 8, except that the deposition time is 600 min.

Example 12

The heart valvuloplasty ring of this embodiment has a similar structure to the heart valvuloplasty ring of Example 1, the difference being that the outer surface of the polyester cloth outer layer is evenly coated with a 25 μm thick Parylene N coating.

The preparation method of the Parylene N coating is similar to the preparation method of the Parylene N coating in Example 8, except that the deposition time is 1500 min.

Example 13

The heart valvuloplasty ring of this example has a similar structure to the heart valvuloplasty ring of Example 1, the difference being that the outer surface of the polyester cloth outer layer is evenly coated with a 50 μm thick Parylene N coating.

The preparation method of the Parylene N coating is similar to the preparation method of the Parylene N coating in Example 8, except that the deposition time is 3000 min.

Example 14

The heart valvuloplasty ring of this example has a similar structure to the heart valvuloplasty ring of Example 1, the difference being that the outer surface of the polyester cloth outer layer is evenly coated with a 100 μm thick Parylene N coating.

The preparation method of the Parylene N coating is similar to the preparation method of the Parylene N coating in Example 8, except that the deposition time is 6000 min.

Comparative Example 1

The heart valvuloplasty ring of this embodiment has a similar structure to the heart valvuloplasty ring of Embodiment 1, the difference is that the outer surface of the polyester cloth outer layer is not coated with a coating.

Comparative Example 2

The heart valvuloplasty ring of the present embodiment has a similar structure to the heart valvuloplasty ring of embodiment 1, and the difference is that the outer surface of the polyester cloth outer layer is evenly coated with 25 μm thick PTFE (polytetrafluoroethylene, Teflon) coating. Floor.

The preparation method of the PTFE coating includes the following steps: using the vapor phase deposition method to use PTFE powder as an evaporation material, thermally cracking the PTFE raw material into free radicals or excited states, and finally depositing and polymerizing the PTFE coating on the polyester cloth.

Effect example

The heart valvuloplasty rings of the above-mentioned Examples 3-5, 10-12 and Comparative Examples 1 and 2 were respectively implanted in the inferior vena cava of pigs, and the corresponding implanted tissues were taken out after 7 days, paraffin sections were carried out, and HE staining (Su Xylin-eosin staining), the degree of tissue inflammation and thrombosis was observed under a microscope, and the results are shown in Figure 3-10.

It can be seen from the above figure that the inflammatory response and the degree of thrombosis of the tissue implanted with the uncoated annuloplasty ring are obvious; the inflammatory response and the degree of thrombosis of the tissue implanted with the PTFE-coated annuloplasty ring Compared with the former, they were mild; the tissues implanted with Parylene C-type and N-type coated cardiac valvuloplasty rings had the mildest inflammatory response and the lowest degree of thrombosis.

Embodiments of the present invention have been described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementations, and the above-mentioned specific implementations are only illustrative, rather than restrictive, and those of ordinary skill in the art will Under the enlightenment of the present invention, many forms can also be made without departing from the gist of the present invention and the protection scope of the claims, and these all belong to the protection of the present invention.

Claims (9)

1. a kind of valvuloplasty ring including metal inner tube layer, is coated in the layer of silica gel of the metal tube inner layer outer surface Interbed and the woven dacron outer layer for being coated on the layer of silica gel middle layer outer surface, which is characterized in that the woven dacron outer layer Outer surface is coated with the Parylene coating of 0.01~100 μ m-thick.

2. valvuloplasty ring according to claim 1, which is characterized in that the Parylene is Parylene C or Parylene N.

3. valvuloplasty ring according to claim 2, which is characterized in that the thickness of the Parylene coating is 0.1~50 μm.

4. valvuloplasty ring according to claim 2, which is characterized in that when the Parylene to be poly- to diformazan During benzene C, the thickness of the Parylene coating is 0.5~30 μm.

5. valvuloplasty ring according to claim 2, which is characterized in that when the Parylene to be poly- to diformazan During benzene C, the thickness of the Parylene coating is 1~20 μm.

6. valvuloplasty ring according to claim 2, which is characterized in that when the Parylene to be poly- to diformazan During benzene N, the thickness of the Parylene coating is 0.5~35 μm.

7. valvuloplasty ring according to claim 2, which is characterized in that when the Parylene to be poly- to diformazan During benzene N, the thickness of the Parylene coating is 1~25 μm.

8. valvuloplasty ring according to claim 2, which is characterized in that the thickness of the Parylene coating is 1~10 μm.

9. valvuloplasty ring according to claim 1, which is characterized in that the metal tube is NiTi cutting pipe.