Bioabsorbable polymer, non-bioabsorbable metal composite stents
View Patent ↗Biocompatible materials may be configured into any number of implantable medical devices including intraluminal stents. The biocompatible material may comprise metallic and non-metallic materials in hybrid structures. In one such structure, a device may be fabricated with one or more elements having an inner metallic frame that is not degradable with an outer shell formed from a polymeric material that is biodegradable by extrusion blow molding. Additionally, therapeutic agents may be incorporated into the microstructure or the bulk material.
1. A method of producing a substantially tubular intraluminal scaffold comprising:
providing a frame including: a plurality of hoop components configured as the primary radial load bearing elements of the intraluminal scaffold, the hoop components being formed as a continuous series of circumferentially oriented radial strut members and alternating radial arc members, wherein at least one of the plurality of hoop components comprises a non-bioabsorbable metallic material, and one or more connector elements interconnecting the plurality of hoop components, the connector elements comprising a continuous series of longitudinally oriented flexible strut members having substantially equal lengths and alternating flexible arc members forming a substantially N-shaped configuration, wherein the one or more connector elements are fabricated from a first bioabsorbable polymeric material;
extruding a second bioabsorbable polymeric material into a hollow tube inside the frame, the frame being contained inside a mold; and
blowing air into the second bioabsorbable polymeric hollow tube inside the mold so that the second bioabsorbable polymeric material flows through openings of the frame and surrounds edges of the frame to form a one-piece polymer-metal hybrid structure with the non-bioabsorbable metallic material of the at least one of the plurality of hoop components of the frame and the second bioabsorbable polymeric material such that the bioabsorbable polymeric material forms a structural casing completely surrounding the frame and is configured to add structural integrity thereto, wherein a therapeutic agent is distributed throughout the second bioabsorbable polymeric material of the polymer-metal hybrid composite structure, the second bioabsorbable polymeric material of the polymer-metal hybrid composite structure being configured to hold a dose of the therapeutic agent.
2. A method of producing a substantially tubular intraluminal scaffold comprising:
providing a frame including: a plurality of hoop components configured as the primary radial load bearing elements of the intraluminal scaffold, the hoop components being formed as a continuous series of circumferentially oriented radial strut members and alternating radial arc members, wherein at least one of the plurality of hoop components comprises a non-bioabsorbable metallic material, and one or more connector elements interconnecting the plurality of hoop components, the connector elements comprising a continuous series of longitudinally oriented flexible strut members having substantially equal lengths and alternating flexible arc members forming a substantially N-shaped configuration, wherein the one or more connector elements are fabricated from a first bioabsorbable polymeric material and include a first therapeutic agent;
extruding a second bioabsorbable polymeric material into a hollow tube inside the frame, the frame being contained inside a mold; and
blowing air into the second bioabsorbable polymeric hollow tube inside the mold so that the second bioabsorbable polymeric material flows through openings of the frame and surrounds edges of the frame to form a one-piece polymer-metal hybrid structure with the non-bioabsorbable metallic material of the at least one of the plurality of hoop components of the frame and the bioabsorbable polymeric material such that the second bioabsorbable polymeric material forms a structural casing completely surrounding the frame and is configured to add structural integrity thereto, wherein a second therapeutic agent is distributed throughout the second bioabsorbable polymeric material of the polymer-metal hybrid composite structure, the second bioabsorbable polymeric material of the polymer-metal hybrid composite structure being configured to hold a dose of the second therapeutic agent.