JP2003310744A - Medical covering members - Google Patents

Abstract

(57) [Summary] [Problem] A DLC film that has strong adhesion to medical materials and high abrasion resistance and has sufficient adhesion resistance to human tissues such as blood, muscle, blood vessels, etc. Provided is a medical DLC covering member formed on a substrate. SOLUTION: It has SP2 bond and SP3 bond, and
Within 0.1 μm from the interface between the DLC coating and the member,
The SP2 / SP3 ratio of the diamond-like carbon film is 1 to 10
And a medical member having a DLC coating having a continuous or discontinuous fluorine concentration gradient in a range of 10 to 40% by volume of fluorine at a depth of 0.1 μm or less from the surface of the DLC coating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical member having adhesion resistance and pseudo-adhesion resistance, as well as strong adhesion to a base material and high abrasion resistance. Further, the present invention provides various medical members that directly contact with indwelling devices such as catheters, guide wires, stents, and pacemaker leads, human needles such as injection needles, scalpels, (wound holding parts), and blood. Regarding

[0002]

2. Description of the Related Art Conventionally, it has been disclosed that a medical device is coated with DLC and that the entire coating contains fluorine, and the inventions described below are known. For example, JP-A-11-3
Japanese Patent No. 13884 includes a stent base material, a carbon ion-implanted layer injected into at least a part of the surface of the stent base material, and a diamond-like carbon film formed on the carbon ion-implanted layer. A stent for living body in which a stent for living body is further laminated with a diamond-like carbon film is disclosed in Japanese Patent Application Laid-Open No. 2001-2.
9447 discloses an implantable medical device characterized in that at least a part of the surface of the medical device main body is coated with a fluorine-containing diamond-like carbon film having an atomic ratio (F / F + C + H) of 60% or more. Open 2001-238
No. 962 discloses a core and a DLC formed on the surface thereof.
Each of the medical insertion wires characterized by having a coating is disclosed.

[0003]

However, in these conventional techniques, although the addition of fluorine improves the antithrombotic property, the addition of fluorine facilitates peeling due to deformation during use of the base material and mechanical There is a problem that wear resistance is reduced. Therefore, it has anti-adhesion and pseudo-adhesion properties to the drugs used, let alone human tissues such as blood, interstitial fluid, blood vessels, and biological tissues, and also has strong adhesion to the base material and high abrasion resistance. There has been a demand for medical parts.

[0004]

[Means for Solving the Problems] In view of the above situation, a diamond-like carbon film containing fluorine is coated to provide a medical coating member having a fluorine concentration within a depth of 0.1 μm from the coating surface of 10 to 40 at%. As a result, the above problems have been solved. In the above-mentioned medical covering member of the present invention, when the depth from the surface of the coating is deeper than 0.1 μm, the absence of fluorine concentration is more excellent in mechanical abrasion resistance and adhesion to the base material.
It may be present as long as it has a low concentration of less than at%, and the concentration may be gradually reduced with respect to the base material.

Further, by controlling the hydrogen concentration within the depth of 0.1 μm from the surface of the film existing in the same area as that of fluorine to 2 to 30 at%, let alone the human body tissue such as blood, tissue fluid, blood vessels, and biological tissues. It is preferable because it is possible to suppress the reduction of mechanical properties while maintaining the anti-adhesion property and the anti-adhesion property to the drug. If the hydrogen concentration is less than 2 at%, the compressive residual stress in the coating increases, so that peeling easily occurs, and if it exceeds 30 at%, the mechanical properties (hardness, crystallinity) deteriorate.
Therefore, the hydrogen concentration within the depth of 0.1 μm from the coating surface was set to 2 to 30 at%. The hydrogen concentration is more preferably 5 to 15 at%.

Further, the diamond-like carbon film is SP2
Bond and SP3 bond, and 0.1 from the interface between the coating and the member.
Having a region with a high SP3 / SP2 ratio within μm is preferable because it improves the adhesion to the medical member that is the base material. The diamond-like carbon film has a thickness of 0.2-2 μ
Controlling to m or less is preferable because desired performance can be further exhibited.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The medical covering material of the present invention has a fluorine-added region on the diamond-like carbon film surface side of a member,
By limiting the fluorine content of the base material to a low level, it has excellent adhesion resistance and pseudo-adhesion resistance not only to human tissues such as blood, tissue fluid, blood vessels and living tissues but also to used pharmaceuticals. Further, a medical coating material having strong adhesion to the base material and high abrasion resistance is obtained.

[0008] The medical coating material in the present invention is a device for indwelling in a body such as a catheter, a guide wire, a stent and a pacemaker lead, and a member such as an injection needle, a scalpel, and a (wound holding component) which come into direct contact with the human body. Examples thereof include a discharge container during treatment and a container such as a vat, but the effect is particularly remarkable in a member that directly contacts the human body. Examples of the material used for the medical covering material of the present invention include metals such as stainless steel, platinum alloy, gold alloy, and tantalum alloy, resins such as polyethylene, polypropylene, polyethylene terephthalate, and ceramics such as alumina and glass. However, they are not bound by these examples. If these base materials are porous, the adhesion of the coating film is poor, so it is preferable that they are dense.

The coating of the diamond-like carbon film in the medical covering material of the present invention can be realized by a physical vapor deposition method or a chemical vapor deposition method. However, it is possible to uniformly coat a complicated shape and it is easy to partially add fluorine. From plasma CV
Method D is preferred.

The diamond-like carbon film is charged in a vacuum apparatus together with a member for covering a carrier gas such as hydrogen and carbon sources such as methane, ethane, propane and benzene, and the introduced gas is ionized. , Is formed on the surface of the member. Partial addition of fluorine is carried out by introducing a fluorine-containing gas such as C ₂ F ₆ , CF ₄ or the like into the apparatus at the same time as the carrier gas and carbon source gas into a diamond-like carbon having a region to which fluorine is added. A film is obtained. The fluorine concentration in the film is controlled by the partial pressure of the fluorine-containing gas to be introduced and the degree of vacuum in the apparatus, and the additional region is controlled by the timing of introducing the fluorine-containing gas.

According to the present invention, not only human body tissues such as blood, muscles and blood vessels but also anti-adhesion and anti-adhesion properties with respect to pharmaceuticals used are 10-40 at% of fluorine concentration within 0.1 μm from the surface.
It has been clarified that the desired effect can be obtained by controlling the above. Furthermore, by controlling the hydrogen concentration in the fluoridation region within 0.1 μm from the surface to be 2 to 30 at%, the human body tissue such as blood, muscles and blood vessels, as well as the adhesion resistance and pseudo-adhesion resistance to the drug used can be prevented. While maintaining the properties, the reduction of mechanical properties is suppressed. Specifically, it can be obtained by lowering the hydrogen partial pressure in the introduced gas.

Further, it has been revealed that the adhesion to the base material is improved by having a region having a high SP3 / SP2 ratio within 0.1 μm from the interface between the coating film and the member. Although there are various crystal structures that a carbon film can have, the present invention includes SP3 bonds (diamond bonds) and SP2 bonds (graphite bonds), and by increasing the amount of SP2 near the interface with the member, the adhesion of the film can be improved. It improves the sex. SP3
The bond (diamond bond) is the strongest bond, so the mechanical properties are excellent, but the SP2 bond is the SP3 bond.
When the amount is larger than the number of bonds, the wear resistance is reduced, but the effect of dispersing the stress is exerted, so that the adhesion with the member is improved. Particularly, when the SP3 / SP2 ratio is 0.01 to 10, it is preferable because high adhesion and excellent wear resistance are exhibited.

The above effects are particularly remarkable in a device that directly contacts the human body such as a medical device implanted in a living body, but a coronary stent will be described in more detail as an example.
Coronary stents are placed in the coronary arteries and are designed to expand in a narrowed vascular lesion. At this time, if it comes into contact with blood or a blood vessel structure, a thrombus will be formed there. Therefore, although this problem is solved by adding a fluorine-like carbon film to the surface, and fluorine is added, naturally, when the stent is expanded, the covering material is also deformed according to the base material, so that it is easily peeled off. I will end up.

Further, when the stent is inserted, it is used together with a medical instrument such as a catheter or a guide wire, so that a reliable manual operation cannot be expected due to abrasion or damage. Therefore, a member coated with a diamond-like carbon film as in the present invention has excellent antithrombogenicity and biocompatibility by providing a fluorine-added region of a specific concentration only on the very surface, and is strong. A stent having both excellent adhesion and high abrasion resistance can be obtained.

Particularly in the case of a stent, the deformation of the stent may occur due to the passage of time, but this is due to the concentration of stress due to the stent-vessel structure and the uneven load of stress. Depending on the product of the present invention, since it has excellent adhesion resistance, stress is uniformly applied to the entire stent to suppress deformation, and SP3 bond and SP2 bond, which are excellent in deformation resistance at a depth deeper than the fluorine-loaded region, are formed. Because it has a structure,
It also has the effect of preventing deterioration over time. Specific examples will be described below.

[0016]

[Example 1] As a substrate for testing, a 30 × 30 × 5 mm shape was used.
A product made of SUS316 was used. The substrate was subjected to various coatings shown in Table 1 and used for evaluation. A plasma CVD apparatus was used for film formation. After cleaning the substrate, the substrate was placed in a film forming apparatus and ion-cleaned by an argon ion bombardment. DLC film formation is 95% hydrogen,
Introduce a mixed gas of benzene 5% to a vacuum degree of 1 × 10 −3,
In the fluorine-added region, the C ₂ F ₆ Was mixed in at a rate of 2%. In the apparatus, high-frequency power of 13.56 MHz and power of 1 kW was applied to generate plasma, and a film was formed. As for the ratio of SP2 coupling to SP3 coupling, when the input power was 200 W, a region with a large amount of SP2 coupling was formed, and the power was continuously increased to 1 kW. As a comparison
What forms TiN coating is HCD (hollow cathode) type PV
A TiN film was formed by vapor depositing Ti in a D apparatus in a mixed plasma of argon-nitrogen. The film thickness was 1.1 μm.

[0017]

[Table 1]

The obtained sample was evaluated by three kinds of tests. (1) Test 1: After dropping 3 cc of blood to fix it, a peeling test was conducted with an adhesive tape. The amount of hardened blood remaining in the samples was compared. (2) Test 2: While the load was continuously increased from 0 to 10 N with a diamond indenter, the critical loads until the film peeled off when scratched from above the film were compared. Peeling at 5N or less: ▲, Peeling at 6 to 10N: ○, No peeling (minor defects): ◎ (3) Test 3: 0.2m / ring of ring-shaped (30Φ) carbon steel (S20C)
While rotating at s, the sample coated surface was slid in blood with a load of 100 g, and the amount of wear after 10 minutes was compared by the wear width. 5 mm or more: ×, 3 to 5 mm: △, 1 to 3 mm: ○, 1 mm or less: ◎

[0019]

[Table 2]

[0020]

[Embodiment 2] The substrate for the test has a shape of 15φ × 0.3 mm,
Inventive products 1 and 2 and comparative products 3 and 4 were implanted subcutaneously in rats and evaluated by the following tests. Test 4: In order to hematologically evaluate the acute phase inflammatory reaction one week after subcutaneous implantation in the rat, a component in blood, IL-1
β, TNF-α and C3a are compared and evaluated in Table 3. Test 5: The neutrophils and lymphocytes were compared and evaluated in Table 4 in order to pathologically evaluate the chronic phase tissue reaction 12 weeks after subcutaneous implantation in the rat. Test 6: When implanted subcutaneously in a rat, it was folded in two, and 12 weeks later, the film peeling and biological reaction state were compared and evaluated in Table 5.

[0021]

[Table 3]

[0022]

[Table 4]

[0023]

[Table 5]

As is clear from Tables 3 and 4, the biocompatibility was found to be excellent. Furthermore, as a result of evaluating the adhesion of the coating and the adhesion of the living body, as is clear from Table 5, the peeling of the coating or the adhesion of the living body (adhesion) was observed in the comparative product.
However, the product of the present invention also showed excellent performance in terms of the adhesion of the coating film and the state of adherence to a living body.

[0025]

According to the present invention, the DLC film is formed on the surface of the medical member by appropriately adjusting the contained fluorine concentration, hydrogen concentration, SP2 / SP3 ratio and film thickness of the DLC film. DLC on the surface obtained by
The medical covering member coated with is excellent in adhesion resistance and has mechanical abrasion resistance and adhesion as well as adhesion resistance. In addition, mechanical properties can be suppressed while maintaining anti-adhesion and pseudo-adhesion resistance to human tissues such as blood, muscles, blood vessels, etc. or pharmaceuticals. In addition, the medical DLC of the present invention
It was found that the coated member has improved wear resistance and improved adhesion of the DLC film to the substrate, and the medical device obtained is a practical and extremely stable member. .

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) A61B 17/32 310 A61M 5/32 4G077 A61M 5/32 29/02 25/01 A61N 1/05 29/02 A61L 33/00 Z A61N 1/05 A61M 25/00 450B F-term (reference) 4C053 CC02 4C060 AA00 FF03 MM24 4C066 AA09 BB01 FF05 4C081 AA01 AC06 AC08 AC09 BA02 BB30A06 BBBB30B06B41BB05A06B30BB06B41BB05A06B30BB06A05BB30B06A05BB30A06B30BB06A06B30BB06B30H06A06B30H06AH 4G077 AA03 BA03 DB18 EB01 HA20 TA03 TB02 TB07 TC02 TK10 TK13

Claims (6)

[Claims] 1. A diamond-like carbon film containing fluorine is coated so that a fluorine concentration within a depth of 0.1 μm from the coating surface is 10 or less.
A medical covering member having a fluorine added region of up to 20 at%. 2. The medical covering member according to claim 1, wherein the hydrogen concentration within the depth of 0.1 μm from the surface of the coating is 2 to 30 at%. 3. The diamond-like carbon film comprises SP2 bonds and S
The medical covering member according to claim 1 or 2, which has a P3 bond and has a region having a high SP3 / SP2 ratio within 0.1 µm from an interface between the film and the member. 4. The medical covering member according to claim 3, wherein the SP3 / SP2 ratio is 0.01 to 10. 5. The diamond-like carbon film has a thickness of 0.2 to 2 μm.
m is a medical covering member according to any one of claims 1 to 4. 6. A catheter, a guide wire, a stent, a pacemaker lead, a device for indwelling in a body, an injection needle,
The medical covering member according to any one of claims 1 to 5, which is used for either a scalpel or (wound holding component).