Implantable medical device having biologically active polymeric casing

• US 6,968,234 B2
• Filed: 04/25/2002
• Issued: 11/22/2005
• Est. Priority Date: 04/25/2002
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Stokes, Kenneth B.
• Primary Examiner(s): Getzow, Scott M.
• Application Number:
  US10/131,428
• Publication Number:
  US 20030204229A1
• Time in Patent Office: 1,307 Days
• Field of Search: 607 1-156
• US Class Current: 607/36
• CPC Class Codes: A61L 2300/112 Phosphorus-containing compounds, e.g. phosphates, phosphonates
• CPC Class Codes: A61L 2300/204 with nitrogen-containing functional groups, e.g. aminoxides, nitriles, guanidines
• CPC Class Codes: A61L 2300/22 Lipids, fatty acids, e.g. prostaglandins, oils, fats, waxes
• CPC Class Codes: A61L 2300/25 Peptides having up to 20 amino acids in a defined sequence
• CPC Class Codes: A61L 2300/402 Anaestetics, analgesics, e.g. lidocaine
• CPC Class Codes: A61L 2300/404 Biocides, antimicrobial agents, antiseptic agents
• CPC Class Codes: A61L 2300/41 Anti-inflammatory agents, e.g. NSAIDs
• CPC Class Codes: A61L 2300/45 Mixtures of two or more drugs, e.g. synergistic mixtures
• CPC Class Codes: A61L 2300/802 Additives, excipients, e.g. cyclodextrins, fatty acids, surfactants
• CPC Class Codes: A61L 27/34 Macromolecular materials
• CPC Class Codes: A61L 27/54 Biologically active materials, e.g. therapeutic substances A61L27/227 takes precedence
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence

Abstract

An implantable medical device has a medical unit, such as a pacemaker lead, and a casing at least partially enclosing the medical unit. The casing is formed of a base polymer such as a polyurethane, a polyurethane copolymer, a fluoropolymer and a polyolefin or a silicone rubber. The casing has biologically active agents covalently bonded to the base polymer. The biologically active agents can be attached to the base polymer as surface active end groups. As an alternative, the biologically active may be attached to a backbone the base polymer. As yet a further alternative, the biologically active agents may be attached to surface modifying end groups, which are in turn attached to the base polymer. Examples of suitable biologically active agents are microbial peptide agents, detergents, non-steroidal anti-inflammatory drugs, cations, amine-containing organosilicones, diphosphonates, fatty acids and fatty acid salts.

Claims

1. An implantable medical device, comprising:

a medical unit for long term implantation in a subject; and

a casing at least partially enclosing the medical unit, the casing comprising a base polymer selected from the group consisting of polyurethanes, polyurethane copolymers, fluoropolymers, polyolefins, epoxies and silicone rubbers, a polythylene oxide surface modifying end group covalently bonded to the base polymer, and a biologically active agent attached to the surface modifying end group selected from a group consisting of microbial peptide agents, antibiotics, detergents, non-steroidal anti-imflammatory drugs, cations, amine-containing organosilicones, diphosphonates, fatty acids, fatty acid salts, and wherein the biologically active agent is released in the presence of biological conditions indicative of infection by the polyethylene oxide surface modifying end group breaking off the base polymer due to oxidation casued by cellular inflammation attendant an attack by macrophages.

2. An implantable medical device according to claim 1, wherein the medical unit comprises one of:

a pacemaker lead, a defibrillation lead, a neurological stimulation lead, a combination pacing and defibrillation lead, an artificial heart valve.

3. An implantable medical device according to claim 1, wherein

the medical unit furthur comprises a shell having an outer surface, and

the casing is formed on at least a portion of the outer surface of the shell.

4. An implantable medical device according to claim 1, wherein at least two different biologically active agents are attached to the base polymer.