Stock material or miscellaneous articles – Composite – Of epoxy ether
Reexamination Certificate
2002-01-25
2004-12-07
Dawson, Robert (Department: 1712)
Stock material or miscellaneous articles
Composite
Of epoxy ether
C427S002100, C427S002120, C427S386000, C427S402000, C428S414000
Reexamination Certificate
active
06828028
ABSTRACT:
FIELD OF ART
The present invention relates to a medical material having both the surface lubricity and blood compatibility with a coating layer that is safe and excellent in stability with the lapse of time, and a process for producing the same.
BACKGROUND ART
There have hitherto been made various researches on surface treatment methods for modifying and improving the surface function of a material constituting a medical instrument. Particularly, it is important that a medical instrument for use in direct contact with blood has a surface with an improved blood compatibility in order to minimize the performance degradation of the medical instrument due to the formation of thrombus, and the occurrence of serious complication due to the separation of thrombus from the surface of the base material. In addition to the blood compatibility, medical instruments, e.g. a catheter to be directly inserted from outside of the body into a blood vessel, and a guidewire for guiding the catheter to a target site in the blood vessel, are required to have a surface lubrication from the viewpoint of the improvement of the operability, and the reduction of damage of a tissue such as a blood vessel.
As the most practical method for imparting these functions to the surface of a medical instrument, there have been made various researches on surface modification methods by means of a hydrophilic polymer. The surface modification of the medical instrument with a hydrophilic polymer may preferably be chemical fixation of the hydrophilic polymer on the surface of the base material rather than simple coating for the safety and the persistence of the effect. A large number of researches have hitherto been made on the method for fixing the hydrophilic polymer onto the surface of the base material. Among them, there has been proposed a method utilizing a surface coupling reaction using an epoxy group.
As an example of the improvement of the blood compatibility of a medical instrument by fixing a hydrophilic polymer through an epoxy group, Japanese Laid-Open Patent Publication No. JP-A-7-184989 discloses a method in which either of (i) the polymeric material obtained by crosslinking a copolymer of 2-(methacryloyloxy)ethyl-2′-(trimethylammonio)ethyl phosphate (below, abbreviated as MPC) and an epoxy-group containing monomer with a compound having two or more groups of at least either of an amino group and a carboxyl group; or (ii) the polymeric material obtained by crosslinking a copolymer of MPC and at least one monomer of an amino group-containing monomer and a carboxyl group-containing monomer with a compound having two or more epoxy groups is attached to the surface of a medical material. Japanese Laid-Open Patent Publication No. JP-A-7-184990 discloses a method in which a copolymer of MPC, an epoxy group-containing monomer, and at least one monomer of a hydroxyl group-containing monomer, an amino group-containing monomer, and a carboxyl group-containing monomer is fixed on the surface of a base material.
However, the resulting crosslinked film of MPC copolymer after the heat treatment in any of the foregoing methods has high possibility to contain highly toxic residual epoxy groups, which may give a harmful effect on the human body when the film is located in the body.
Japanese National Phase PCT Laid-Open Publication No. JP-A-7-502053 (WO93/01221) discloses an MPC polymer having a pendant group for stably binding the polymer to a surface, a production method thereof, and a method for giving biocompatibility on the surface by binding the polymer to a base material.
However, this method also has a problem in terms of safety when the pendant group is an epoxy group. Further, any studies on the surface lubricity have not been done for any of the aforementioned materials to which the MPC polymers have been bound, and there is thus no description on the function.
For the surface lubrication of a medical instrument using a hydrophilic polymer, for example, the following methods are disclosed: a method in which a surface of a base material having a proton donating group capable of reacting with the reactive functional group is coated with a water-swellable polymer having a reactive functional group in the molecule (Japanese Laid-Open Patent Publication No. JP-A-6-285152); a method in which, onto a medical instrument surface made of a base material of a synthesized polymer having an acid anhydride in its molecule, a water-swellable polymer having a functional group capable of reacting with the acid anhydride is fixed (Japanese Laid-Open Patent Publication No. JP-A-7-204262); a method in which an insolubilized product of a mixture of a hydrophilic polymer having a reactive functional group in its molecule and a polymer having a functional group capable of reacting with the reactive functional group is formed on the surface of a base material of a medical instrument (Japanese Laid-Open Patent Publication No. JP-A-8-24327); a method in which, onto the base surface of a medical instrument made of polyolefin or modified polyolefin, a mixture of a resin having adhesiveness to the polyolefin or the modified polyolefin and an insolubilized product of a hydrophilic polymer having a reactive functional group in its molecule is bound, or a method in which the hydrophilic polymer is bound to the base surface through the adhesive resin (Japanese Patent Laid-Open Publication No. JP-A-8-24328); a method in which a water soluble or water swellable polymer is immobilized by forming an interpenetrating network structure (IPN) with the base of a medical instrument (Japanese Patent Laid-Open Publication No. JP-A-8-33704); a method in which a hydrogel made of an insolubilized product of a water soluble or water swellable polymer having a reactive functional group in the molecule and an antithrombotic agent is formed on the surface of a medical instrument (Japanese Patent Laid-Open Publication No. JP-A-8-19599); a method in which a hydrophilic polymer having a reactive heterocyclic group is immobilized on the base surface of a medical instrument to which a functional group reactive with the reactive heterocyclic group has previously been introduced (WO90/01344); and a method in which a copolymer containing &ohgr;-carboxy(meth)acrylate and an epoxy group-containing vinyl monomer is immobilized on the base surface of a medical instrument onto which a polymer having a proton donating group reactive with an epoxy group has previously been applied (Japanese Patent Laid-Open Publication No. JP-A-10-20180).
With any of these methods, when the polymer involved in the lubricity is a hydrophilic polymer having an epoxy group in its molecule, the crosslinking in the coating film may occur with the lapse of time, which results in lowering of the water holding capacity of the film, and loss of the wet surface lubricity of the film. In addition to such a problem of the time-dependent degradation of the product performance, there is also a problem in terms of safety. Further, all the various lubricated surfaces described above have insufficient blood compatibility.
DISCLOSURE OF THE INVENTION
It is an object of the present invention to provide a medical material having the surface which is safe and excellent in stability with the lapse of time, which has both a high durability that is necessary for establishing a long-lasting surface lubricity in a wet state as well as an excellent compatibility with blood, and a production method thereof.
According to the present invention, there is provided a medical material obtained by forming a coating layer with a coating material containing a polymeric substance (A) having a heterocyclic group represented by the formula (1) on at least a part of a surface of a medical material base, and ring-opening the heterocyclic group remaining in the coating layer by a nucleophilic compound (N):
(wherein X denotes O, NH, or S, and R
1
denotes H or CH
3
).
According to the present invention, there is also provided a medical material obtained by forming a coating layer with a coating material containing a polymeri
Fukui Hiroki
Ishihara Kazuhiko
Nakabayashi Nobuo
Shuto Kenshiro
Suzuki Ken
Darby & Darby
Dawson Robert
Feely Michael
NOF Corporation
LandOfFree
Medical materials and process for producing the same does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Medical materials and process for producing the same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Medical materials and process for producing the same will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3325908