Biodegradable stent with enhanced fracture toughness

• US 9,517,149 B2
• Filed: 10/09/2013
• Issued: 12/13/2016
• Est. Priority Date: 07/26/2004
• Status: Active Grant

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Inventors: Gale, David C., Huang, Bin, Schaible, Stephen
• Primary Examiner(s): Sweet, Thomas J
• Assistant Examiner(s): Wolf, Megan
• Application Number:
  US13/998,199
• Publication Number:
  US 20140107762A1
• Time in Patent Office: 1,161 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2/9522 Means for mounting a stent or stent-graft onto or into a placement instrument
• CPC Class Codes: A61F 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2002/91566 connected trough to trough
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61L 31/06 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds A61L31/041 takes precedence
• 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: B29C 2049/7831 characterised by pressure values or ranges
• CPC Class Codes: B29C 2793/0009 Cutting out
• CPC Class Codes: B29C 2949/08 Preforms made of several individual parts, e.g. by welding or gluing parts together
• CPC Class Codes: B29C 35/045 using gas or flames
• CPC Class Codes: B29C 49/0005 characterised by the material
• CPC Class Codes: B29C 49/14 Clamps
• CPC Class Codes: B29C 49/4823 with incorporated heating or cooling means
• CPC Class Codes: B29C 55/24 radial
• CPC Class Codes: B29C 69/001 a shaping technique combined with cutting, e.g. in parts or slices combined with rearranging and joining the cut parts for reinforced material B29C70/545; B29C49/4278, B29C51/268 take precedence
• CPC Class Codes: B29K 2067/00 : Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2067/046 : PLA, i.e. polylactic acid or polylactide
• CPC Class Codes: B29K 2105/258 : Tubular
• CPC Class Codes: B29K 2995/006 : Bio-degradable, e.g. bioabsorbable, bioresorbable or bioerodible
• CPC Class Codes: B29L 2031/7534 : Cardiovascular protheses
• CPC Class Codes: C08L 67/04 : Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence

Abstract

Stents and methods of manufacturing a stents with enhanced fracture toughness are disclosed.

Claims

1. A biodegradable stent comprising:

a scaffold including struts comprising a poly(L-lactide)-based biodegradable polymer, wherein the struts have a luminal surface and an abluminal surface, wherein the polymer has induced polymer orientation in a circumferential direction, and wherein the induced polymer orientation decreases from the luminal surface to the abluminal surface of the struts, wherein the polymer has the induced polymer orientation in a radial section between the luminal surface and a transition radial distance and no induced polymer orientation between the transition radial distance and the abluminal surface, and wherein the transition radial distance is ⅓

to ½

of a radial thickness of the struts.

2. The stent of claim 1, wherein the scaffold is formed by cutting a pattern in a radially expanded tube having the induced polymer orientation that was induced by radially expanding the tube.

3. The stent of claim 1, wherein a degree of the induced polymer orientation is uniform around a circumference of the scaffold.

4. A biodegradable stent comprising:

a scaffold including struts comprising a poly(L-lactide)-based biodegradable polymer, wherein the struts have a luminal surface and an abluminal surface, and wherein a luminal radial section of the struts exhibits birefringence and an abluminal radial section is optically isotropic when viewed with polarized light, wherein the luminal radial section has a thickness that is ⅓

to ½

of a radial thickness of the struts from the luminal surface to the abluminal surface.