USE OF PLASMA IN FORMATION OF BIODEGRADABLE STENT COATING

• Main Authors: KAPLAN, STEPHEN L, RUANE, PATRICK H, KIMURA, TORSTEN, LANG, ERIC A
• Format: Patent
• Language: English; French; German
• Published: 25.02.2009
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; BANDAGES, DRESSINGS OR ABSORBENT PADS; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS, ORSURGICAL ARTICLES; CHEMISTRY; COMPOSITIONS BASED THEREON; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF,TUBULAR STRUCTURES OF THE BODY, E.G. STENTS; DISINFECTION, STERILISATION, OR DEODORISATION OF AIR; FILTERS IMPLANTABLE INTO BLOOD VESSELS; FIRST-AID KITS; FOMENTATION; GENERAL PROCESSES OF COMPOUNDING; HUMAN NECESSITIES; HYGIENE; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS, OR SURGICALARTICLES; MEDICAL OR VETERINARY SCIENCE; METALLURGY; METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS INGENERAL; ORGANIC MACROMOLECULAR COMPOUNDS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; PROSTHESES; THEIR PREPARATION OR CHEMICAL WORKING-UP; TREATMENT OR PROTECTION OF EYES OR EARS; WORKING-UP

Metallic stents are treated with a gaseous species in a plasma state under conditions causing the species to polymerize and to be deposited in polymerized form on the metallic stent surface prior to the application of a drug-polymer mixture, which is done by conventional non-plasma deposition methods. The drug-polymer mixture once applied forms a coating on the stent surface that releases the drug in a time-release manner and gradually erodes, leaving only the underlying plasma-deposited polymer. In certain cases, the plasma-deposited polymer itself erodes or dissolves into the physiological medium over an extended period of time, leaving only the metallic stent. While the various polymers and drug remain on the stent, the plasma-deposited polymer enhances the adhesion of the drug-polymer anchor coating and maintains the coating intact upon exposure to the mechanical stresses encountered during stent deployment.