Biodegradable coating with inhibitory properties for application to biocompatible materials

A biomaterial device adapted to be placed in contact with human blood in connection with a medical, surgical, therapeutic, restorative, prosthetic, or pathological procedure;

• said device comprising:
• a biomaterial;
• and
• a thin, adhesive layer of material coating a surface of the biomaterial for continuous disintegration as a function of time when said layer is in contact with blood, said layer including:
• a biodegradable carrier material having biological compatibility with blood and tissue of the human body, and
• a substance incorporated in said carrier material and having at least one inhibitory property selected from the group consisting of anti-coagulant, anti-thrombotic, anti-inflammatory, anti-proliferative, anti-stenotic, and antibiotic, for timed release from said biodegradable carrier material with disintegration thereof when said device has been introduced into the body of the patient,
• said layer having a formulation, pattern and thickness selected according to the period of time over which said incorporated substance is to perform its inhibitory property action, said layer thickness being less than about 100 microns.

A method of providing a vascular stent of tubular configuration with the capability of localized action when deployed at a treatment site of an earlier procedure for opening the lumen of a blood vessel of a patient, wherein said action is to prevent both early thrombus formation on the stent and late restenosis attributable to the lumen opening procedure in the locality of the treatment site, without producing any other substantial systemic effects on the patient, said method comprising the steps of:

• preparing a liquid solution of biodegradable material having biological compatibility with blood and tissue of the human body, together with a substantially inert solvent;
• adding an anti-thrombotic substance to said liquid solution of the biodegradable material to produce a liquid coating material;
• adhesively applying the liquid coating material to an interior surface of the stent tubular configuration in a substantially continuous layer overlying said interior surface and having a formulation, pattern and thickness selected according to the period of time over which the coating material is to perform its anti-thrombotic action, and thereafter drying the coating material to a layer thickness less than about 100 microns for continuous disintegration thereof as a function of time when said stent layer is in contact with flowing blood;
• preparing a second liquid solution of said biodegradable material together with said substantially inert solvent;
• adding an anti-stenotic substance to said second liquid solution of biodegradable material to produce a second liquid coating material;
• adhesively applying the second liquid coating material to an exterior surface of the stent tubular configuration in a substantially continuous layer overlying said exterior surface and having a formulation, pattern and thickness selected according to the period of time over which the second coating material is to perform its anti-stenotic action, and thereafter drying the second coating material to a layer thickness less than about 100 microns for continuous disintegration thereof as a function of time when said layer is in contact with flowing blood.