Coating medical devices using air suspension

• US 6,368,658 B1
• Filed: 04/17/2000
• Issued: 04/09/2002
• Est. Priority Date: 04/19/1999
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Miller, Kathleen, Kamath, Kalpana, Schwarz, Marlene
• Primary Examiner(s): Parker, Fred J.
• Assistant Examiner(s): Michener, Jennifer Kolb
• Application Number:
  US09/551,614
• Time in Patent Office: 722 Days
• Field of Search: 427/2.24, 427/2.25, 427/2.28, 427/2.3, 427/2.15, 427/313, 427/5, 427/6, 427/457, 427/458, 427/459, 427/460, 427/523, 427/581, 427/582, 427/585, 427/496, 427/488, 427/595, 427/596, 427/248.1, 427/255.5, 427/255.6, 118/309, 118/DIG.5
• US Class Current: 427/2.15
• CPC Class Codes: A61L 2300/252 Polypeptides, proteins, e.g. glycoproteins, lipoproteins, cytokines
• CPC Class Codes: A61L 2300/258 Genetic materials, DNA, RNA, genes, vectors, e.g. plasmids
• CPC Class Codes: A61L 2300/606 Coatings
• CPC Class Codes: A61L 2300/608 having two or more layers
• CPC Class Codes: A61L 2420/02 Methods for coating medical devices
• CPC Class Codes: A61L 27/28 Materials for coating prostheses
• CPC Class Codes: A61L 27/54 Biologically active materials, e.g. therapeutic substances A61L27/227 takes precedence
• CPC Class Codes: A61L 29/08 Materials for coatings
• CPC Class Codes: A61L 29/16 Biologically active materials, e.g. therapeutic substances A61L29/048 takes precedence
• CPC Class Codes: A61L 31/08 Materials for coatings
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: A61L 31/14 Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
• CPC Class Codes: A61L 31/16 Biologically active materials, e.g. therapeutic substances A61L31/047 takes precedence
• CPC Class Codes: B05B 13/02 Means for supporting work; Arrangement or mounting of spray heads; Adaptation or arrangement of means for feeding work B05B13/06 takes precedence
• CPC Class Codes: B05B 13/0221 characterised by the means for moving or conveying the objects or other work, e.g. conveyor belts B05B13/0207 takes precedence; conveyors in general B65G
• CPC Class Codes: B05B 13/025 the objects or work being present in bulk
• CPC Class Codes: B05B 13/0257 in a moving container, e.g. a rotatable foraminous drum
• CPC Class Codes: B05C 13/00 Means for manipulating or holding work, e.g. for separate articles B05C1/0821 takes precedence
• CPC Class Codes: B05D 1/22 using fluidised-bed technique fluidised-bed technique in general B01J8/24
• CPC Class Codes: C23C 14/50 Substrate holders
• CPC Class Codes: C23C 16/458 : characterised by the method used for supporting substrates in the reaction chamber

Abstract

Methods and apparatuses for coating medical devices and the devices thereby produced are disclosed. In one embodiment, the invention includes a method comprising the steps of suspending the medical device in an air stream and introducing a coating material into the air stream such that the coating material is dispersed therein and coats at least a portion of the medical device. In another embodiment, the medical devices are suspended in an air stream and a coating apparatus coats at least a portion of the medical device with a coating material. The coating apparatus may include a device that utilizes any number of alternative coating techniques for coating the medical devices. This process is used to apply one or more coating materials, simultaneously or in sequence. In certain embodiments of the invention, the coating materials include therapeutic agents, polymers, sugars, waxes, or fats. By using air suspensions to coat medical devices, the methods of the present invention result in coatings having minimal defects and uniform thicknesses and mechanical properties. Further, the methods of the present invention are time efficient and cost effective because they facilitate the coating of numerous medical devices in a single batch, resulting in numerous medical device units containing substantially the same coating.

Claims

1. A method for coating at least a portion of a medical device for placement into a body lumen of a patient, comprising:

providing a medical device having a surface;

suspending said medical device in an air stream, said air stream substantially devoid of suspending particles; and

coating at least a portion of said surface of said suspended medical device with a first coating material, wherein said step of coating at least a portion of said surface of said medical device with a first coating material includes ionization deposition.

2. A method for coating at least a portion of a medical device for placement into a body lumen of a patient, comprising:

providing a medical device having a surface;

suspending said medical device in an air stream, said air stream substantially devoid of suspending particles; and

coating at least a portion of said surface of said suspended medical device with a first coating material, wherein said step of coating at least a portion of said surface of said medical device with a first coating material includes at least one of plasma treatment, plasma grafting or plasma deposition.

3. A method for coating at least a portion of a medical device for placement into a body lumen of a patient, comprising:

providing a medical device having a surface;

suspending said medical device in an air stream, said air stream substantially devoid of suspending particles; and

coating at least a portion of said surface of said suspended medical device with a first coating material, wherein said step of coating at least a portion of said surface of said medical device with a first coating material includes chemical vapor deposition.

4. A method for coating at least a portion of a medical device for placement into a body lumen of a patient, comprising:

providing a medical device having a surface;

suspending said medical device in an air stream, said air stream substantially devoid of suspending particles; and

coating at least a portion of said surface of said suspended medical device with a first coating material, wherein said step of coating at least a portion of said surface of said medical device with a first coating material includes electrostatic deposition.

5. A method for coating at least a portion of a medical device for placement into a body lumen of a patient, comprising:

providing a medical device having a surface;

suspending said medical device in an air stream, said air stream substantially devoid of suspending particles; and

coating at least a portion of said surface of said suspended medical device with a first coating material, wherein said step of coating at least a portion of said surface of said medical device with a first coating material includes at least one of a microwave deposition, microwave polymerization, or microwave treatment process.

6. A method for coating at least a portion of a medical device for placement into a body lumen of a patient, comprising:

providing a medical device having a surface;

suspending said medical device in an air stream, said air stream substantially devoid of suspending particles; and

coating at least a portion of said surface of said suspended medical device with a first coating material, wherein said step of coating at least a portion of said surface of said medical device with a first coating material includes at least one of an ultraviolet deposition, ultraviolet polymerization, or ultraviolet treatment process.

7. A method for coating at least a portion of a medical device for placement into a body lumen of a patient, comprising:

providing a medical device having a surface;

suspending said medical device in an air stream, said air stream substantially devoid of suspending particles; and

coating at least a portion of said surface of said suspended medical device with a first coating material, wherein said step of coating at least a portion of said surface of said medical device with a first coating material includes at least one of a visible light deposition, visible light polymerization, or visible light treatment process.

8. A method for coating at least a portion of a medical device for placement into a body lumen of a patient, comprising:

providing a medical device having a surface;

suspending said medical device in an air stream, said air stream substantially devoid of suspending particles; and

coating at least a portion of said surface of said suspended medical device with a first coating material, wherein said step of coating at least a portion of said surface of said medical device with a first coating material includes at least one of an electron-beam deposition, electron-beam polymerization, or electron-beam treatment process.

9. A method for coating at least a portion of a medical device for placement into a body lumen of a patient, comprising:

providing a medical device having a surface;

suspending said medical device in an air stream, said air stream substantially devoid of suspending particles; and

coating at least a portion of said surface of said suspended medical device with a first coating material, wherein said step of coating at least a portion of said surface of said medical device with a first coating material includes at least one of a thermal evaporation deposition, thermal evaporation polymerization, or thermal evaporation treatment process.

10. A method for coating at least a portion of a medical device for placement into a body lumen of a patient, comprising:

providing a medical device having a surface;

suspending said medical device in an air stream, said air stream substantially devoid of suspending particles; and

coating at least a portion of said surface of said suspended medical device with a first coating material, wherein said first coating material comprises a therapeutic agent.

11. The method of claim 10, wherein said first coating material further comprises a polymer, sugar, wax, or fat.

12. The method of claim 10, wherein said therapeutic agent is selected from the group consisting of pharmaceutically active compounds, proteins, oligonucleotides, DNA compacting agents, recombinant nucleic acids, gene/vector systems, and nucleic acids.

16. The method of claim 10, wherein said first coating material further comprises a solvent in which said therapeutic agent is at least partially soluble.

17. The method of claim 10, wherein said first coating material further comprises a solvent in which said therapeutic agent is at least partially dispersed.

13. A method for coating at least a portion of a medical device for placement into a body lumen of a patient, comprising:

providing a medical device having a surface;

suspending said medical device in an air stream, said air stream substantially devoid of suspending particles; and

coating at least a portion of said surface of said suspended medical device with a first coating material, wherein said first coating material comprises a polymer, sugar, wax, or fat.

14. The method of claim 13, wherein said first coating material further comprises a therapeutic agent.

15. The method of claim 13, wherein said polymer is selected from the group consisting of polycarboxylic acids, cellulosic polymers, gelatin, proteins, polypeptides, polyvinylpyrrolidone, maleic anhydride polymers, polyamides, polyvinyl alcohols, polyethylene oxides, glycosaminoglycans, polysaccharides, polyesters, polyurethanes, polystyrenes, copolymers, silicones, polyorthoesters, polyanhydrides, copolymers of vinyl monomers, polycarbonates, polyethylenes, polypropylenes, polylactic acids, polyglycolic acids, polycaprolactones, polyhydroxybutyrate valerates, polyacrylamides, polyethers, polyurethane dispersions, polyacrylates, acrylic latex dispersions, polyacrylic acid, mixtures and copolymers thereof, and monomers that are cross-linked or polymerized on said first coating material.

18. The method of claim 13, wherein said first coating material further comprises a solvent in which said polymer, sugar, wax, or fat is at least partially soluble.

19. The method of claim 13, wherein said first coating material further comprises a solvent in which said polymer, sugar, wax, or fat is at least partially dispersed.

20. The method of claim 13, wherein said first coating material further comprises a solvent wherein said solvent is aqueous or non-aqueous.

21. A method for coating at least a portion of a medical device for placement into a body lumen of a patient, comprising:

providing a medical device having a surface;

suspending said medical device in an air stream, said air stream substantially devoid of suspending particles;

coating at least a portion of said surface of said suspended medical device with a first coating material; and

coating at least a portion of said surface of said medical device with a second coating material.

22. The method of claim 21 wherein said step of coating at least a portion of said surface of said medical device with a second coating material includes the step of introducing said second coating material into said air stream such that said second coating material is dispersed therein.

23. The method of claim 21 wherein said step of coating at least a portion of said surface of said medical device with said second coating material is conducted after said step of coating a least a portion of said surface of said medical device with said first coating material is completed thereby providing an outer coating of said second coating material on said medical device.

24. The method of claim 21 wherein said step of coating at least a portion of said surface of said medical device with said second coating material is conducted simultaneously with said step of coating a least a portion of said surface of said medical device with said first coating material.

25. The method of claim 21 wherein said first coating material comprises apolymer, sugar, wax, or fat and said second coating material comprises a therapeutic agent.

26. The method of claim 25 wherein said step of coating at least a portion of said surface of said medical device with said second coating material is conducted after said step of coating a least a portion of said surface of said medical device with said first coating material is completed.

27. The method of claim 25 wherein said step of coating at least a portion of said surface of said medical device with said second coating material is conducted simultaneously with said step of coating a least a portion of said surface of said medical device with said first coating material.

28. A method for coating at least a portion of a medical device for placement into a body lumen of a patient, comprising:

providing a medical device having a surface wherein said medical device comprises a catheter;

suspending said medical device in an air stream, said air stream substantially devoid of suspending particles; and

coating at least a portion of said surface of said suspended medical device with a first coating material.

29. A method for coating at least a portion of a medical device for placement into a body lumen of a patient, comprising:

providing a medical device having a surface wherein said medical device comprises a needle;

suspending said medical device in an air stream, said air stream substantially devoid of suspending particles; and

coating at least a portion of said surface of said suspended medical device with a first coating material.

30. A method for coating at least a portion of a medical device for placement into a body lumen of a patient, comprising:

providing a medical device having a surface wherein said medical device comprises a blood filter;

suspending said medical device in an air stream, said air stream substantially devoid of suspending particles; and

coating at least a portion of said surface of said suspended medical device with a first coating material.

31. A method for coating at least a portion of a medical device for placement into a body lumen of a patient, comprising:

providing a medical device having a surface;

suspending said medical device in an air stream, said air stream substantially devoid of suspending particles; and

coating at least a portion of said surface of said suspended medical device with a first coating material;

wherein said method is conducted in a fluid bed chamber.

32. The method of claim 31 wherein said chamber comprises:

a structure having at least one side wall, a top opening, and a bottom opening;

an air distribution plate within said structure and secured to said side wall at a location between said top and bottom openings of said structure;

wherein

said air distribution plate has openings therein to allow a passage of air therethrough, said openings being smaller than said medical device; and

said air distribution plate defines a coating region above said air distribution plate within said structure.

33. The method of claim 32 wherein said structure is cylindrical.

34. The method of claim 32 wherein said air distribution plate has an open area of about 4 to about 30 percent.

35. The method of claim 32 wherein said air distribution plate comprises a metal screen of about 60 to about 325 mesh.

36. The method of claim 32 wherein said air distribution plate comprises a stationary perforated metal or ceramic plate.

37. The method of claim 32 wherein said air distribution plate comprises a rotatable perforated metal or ceramic plate.

38. The method of claim 32 wherein said air stream passes through said air distribution plate into said coating region.

39. The method of claim 32 wherein said chamber further comprises:

a tubular partition within said coating region, said tubular partition having a longitudinal axis substantially concentric with a longitudinal axis of said structure;

a nozzle positioned beneath said tubular partition substantially along said longitudinal axis of said structure and extending into said coating region, said nozzle injecting said air stream into said tubular partition; and

a second air stream passing through said air distribution plate into said coating region.

40. The method of claim 32 wherein a velocity of said first air stream is greater than a velocity of said second air stream.

41. The method of claim 40 wherein when said medical device is in said chamber, said first air stream pushes said medical device upward through said tubular partition, and said medical device falls downward outside of said tubular partition and through said second air stream.

42. A method for coating at least a portion of a medical device for placement into a body lumen of a patient, comprising:

providing a medical device having a surface;

suspending said medical device in an air stream, said air stream substantially devoid of suspending particles; and

coating at least a portion of said surface of said suspended medical device with a first coating material, wherein said first coating material includes a powder or solid without a solvent.

43. A method for coating at least a portion of a medical device for placement into a body lumen of a patient, comprising:

providing a medical device having a surface wherein said medical device comprises a stent;

suspending said medical device in an air stream, said air stream substantially devoid of suspending particles; and

coating at least a portion of said surface of said suspended medical device with a first coating material, wherein said first coating material comprises a therapeutic agent.

44. A method for coating at least a portion of a medical device for placement into a body lumen of a patient, comprising:

providing a medical device having a surface wherein said medical device comprises a stent;

suspending said medical device in an air stream, said air stream substantially devoid of suspending particles; and

coating at least a portion of said surface of said suspended medical device with a first coating material, wherein said first coating material comprises a therapeutic agent and a polymer.