Medical devices comprising non cross-linked, thin and flexible aqueous coatings, and methods related thereto
Disclosed are medical devices comprising a coil, coated with a multi-layer coating system and possess the flexibility, lubricity and trackability desired in applications where such devices are utilized. The coating system comprises a non-hydrophilic polymer primer coat and a hydrophilic polymer topcoat. These coating materials do not comprise any cross-linkers or reactive functional groups, and do not require the use of a hazardous solvent. The multi-layer coating system is very thin; having a maximum dry thickness in the range of about 15 microns to about 40 microns. Also disclosed are methods for coating and using these medical devices. The coatings are applied at low temperatures, in an aqueous environment, and in such a way that the coil is coated discretely, without forming a thick layer between the coil portions. Such coating prevents substantial bridging between the loops of the coil, thus preventing the coil tip from being stiff or non-trackable.
1. A method for applying a multi-layer lubricious coating to a surface of a medical device comprising a coil, comprising the steps of:
a) applying to the surface of at least a portion of the coil of the medical device comprising a coil, at least one layer of an aqueous non-hydrophilic polymer dispersion capable of adhering to said surface and providing a total dry coating thickness in the range of about 1 micron to about 10 microns; and
b) applying, to the at least one layer of an aqueous non-hydrophilic polymer dispersion, at least one layer of an aqueous hydrophilic polymer composition capable of adhering to the at least one layer of an aqueous non-hydrophilic polymer dispersion and providing a total dry coating thickness in the range of about 2 microns to about 20 microns,
said aqueous non-hydrophilic polymer dispersion or said aqueous hydrophilic polymer composition being free from any cross-linkers,
said aqueous non-hydrophilic polymer dispersion or said aqueous hydrophilic polymer composition being applied via a dip coating, spray coating, painting or pad coating technique,
said multi-layer coating not substantially bridging the space between the successive loop portions of the device coil.
2. A method according to claim 1 , comprising the step of applying, to the at least one layer of an aqueous non-hydrophilic polymer dispersion, at least one layer of a mixture composition, said mixture composition comprising an aqueous non-hydrophilic polymer dispersion and an aqueous hydrophilic polymer composition, capable of adhering to the at least one layer of an aqueous non-hydrophilic polymer dispersion and to the at least one layer of an aqueous hydrophilic polymer composition, and providing a total dry coating thickness in the range of about 2 microns to about 10 microns.
3. A method according to claim 2 , comprising the step of drying the at least one layer of an aqueous non-hydrophilic polymer dispersion prior to the step of applying at least one layer of a mixture composition.
4. A method according to claim 3 , comprising the step of drying the at least one layer of a mixture composition prior to the step of applying at least one layer of an aqueous hydrophilic polymer composition.
5. A method according to claim 1 , comprising the step of drying the at least one layer of an aqueous non-hydrophilic polymer dispersion prior to the step of applying at least one layer of an aqueous hydrophilic polymer composition.
6. A method according to claim 1 , comprising the step of post-baking the a coil coated with the at least one layer of an aqueous hydrophilic polymer composition.
7. A method according to claim 1 , said aqueous non-hydrophilic polymer dispersion being an aqueous polyurethane dispersion.
8. A method according to claim 1 , said aqueous non-hydrophilic polymer dispersion comprising from about 1% to about 5% w/w solids.
9. A method according to claim 1 , said aqueous hydrophilic polymer composition being a solution, a dispersion, or an emulsion, said solution, dispersion, or emulsion comprising poly N-vinylpyrrolidone, poly N-vinylpyrrolidone copolymers, carboxymethylcellulose, polyacrylic acid, polyacrylic acid amide, polyurethane hydrogel, cationically-modified hydroxyethylcellulose, polyethylene oxides, polyethylene oxide copolymers, or any combination thereof.
10. A method according to claim 9 , said aqueous hydrophilic polymer composition being a solution comprising from about 1% to about 5% w/w solids.
11. A method according to claim 1 , said dip coating utilizing a speed of insertion in the range of from about 5 in./min. to about 20 in./min., and a speed of withdrawal in the range of from about 5 in./min. to about 20 in./min.
12. A method for applying a multi-layer lubricious coating to the surface of a medical device comprising a coil, comprising the steps of:
a) applying, to the surface of at least a portion of the coil of a medical device comprising a coil, at least one layer of an aqueous non-hydrophilic polymer composition capable of adhering to said surface and providing a total dry coating thickness in the range of about 1 micron to about 10 microns;
b) drying the at least one layer of an aqueous non-hydrophilic polymer composition;
c) applying, to the dried at least one layer of an aqueous non-hydrophilic polymer composition, at least one layer of an aqueous hydrophilic polymer composition capable of adhering to the at least one layer of an aqueous non-hydrophilic polymer composition and providing a total dry coating thickness in the range of about 2 microns to about 20 microns,
d) subjecting to a RF oxygen plasma treatment: (i) the surface of at least a portion of the coil, prior to the applying at least one layer of an aqueous non-hydrophilic polymer composition, (ii) the surface of the dried at least one layer of an aqueous non-hydrophilic polymer composition, prior to the applying at least one layer of an aqueous hydrophilic polymer composition, or (iii) both i) and ii), said aqueous non-hydrophilic polymer composition or said aqueous hydrophilic polymer composition being applied via a dip coating, spray coating, painting or pad coating technique, and
said multi-layer coating not substantially bridging the space between the successive loop portions of device coil.