Shape memory bioresorbable polymer peripheral scaffolds

• US 10,500,076 B2
• Filed: 05/05/2017
• Issued: 12/10/2019
• Est. Priority Date: 07/23/2012
• Status: Active Grant

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories)
• Original Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories)
• Inventors: Stankus, John J., Zhao, Hugh, Trollsas, Mikael, Hossainy, Syed Faiyaz Ahmed, Ngo, Michael H., Wang, Yunbing, Serna, Benjamyn
• Primary Examiner(s): Miles, Wade
• Application Number:
  US15/588,514
• Publication Number:
  US 20170290688A1
• Time in Patent Office: 949 Days
• CPC Class Codes: A61F 2/86 Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/91508 the meander having a difference in amplitude along the band
• CPC Class Codes: A61F 2002/91541 Adjacent bands are arranged out of phase
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2210/0019 operated at only one temperature whilst inside or touching the human body, e.g. constrained in a non-operative shape during surgery, another temperature only occurring before the operation
• CPC Class Codes: A61F 2230/0054 V-shaped
• CPC Class Codes: A61F 2230/0056 W-shaped, e.g. M-shaped, sigma-shaped
• CPC Class Codes: A61F 2230/006 Y-shaped
• CPC Class Codes: A61F 2250/001 for adjusting a diameter
• CPC Class Codes: A61L 2400/16 Materials with shape-memory or superelastic properties
• CPC Class Codes: A61L 31/041 Mixtures of macromolecular compounds
• 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: A61L 31/148 Materials at least partially resorbable by the body
• CPC Class Codes: A61L 31/16 Biologically active materials, e.g. therapeutic substances A61L31/047 takes precedence
• CPC Class Codes: C08L 67/04 Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence

Abstract

Bioabsorbable scaffolds having high crush recoverability, high fracture resistance, and reduced or no recoil due to self expanding properties at physiological conditions are disclosed. The scaffolds are made from a random copolymer of PLLA and a rubbery polymer such as polycaprolactone.

Claims

1. A stent, comprising:

a scaffold formed from a polymer tube and configured for being crimped to a balloon,

the scaffold having a pattern of interconnected struts and

the scaffold having an expanded diameter when expanded from a crimped state by the balloon,

wherein the scaffold comprises a random copolymer of poly(L-lactide) (PLLA) and polycaprolactone (PCL) and the PCL is 3 to 10 wt % or mol % of the copolymer,

wherein the glass transition temperature of the random copolymer is between 30°

C. and 50°

C.,

wherein the scaffold pattern includes a plurality of undulating rings having crowns and longitudinally extending links connecting one ring to another adjacent ring, wherein the crowns include W-crowns, Y-crowns, and free crowns,

wherein a first link connects a first ring to an adjacent ring, the first link forms with the first ring a W-crown, and the first link forms with the adjacent ring a Y-crown;

wherein the first ring, the adjacent ring, and the first link forms repeating W-V closed cells, and

wherein the W-V cells have three free crowns between the W-crown and a Y-crown.

2. The stent of claim 1, wherein the scaffold attains greater than about 80% of the expanded diameter after being crushed to at least 50% of the expanded diameter.

3. The stent of claim 1, wherein the scaffold comprises a blend of the copolymer and another polymer.

4. The stent of claim 1, wherein a glass transition temperature (Tg) of the copolymer changes by less than 15% from a dry to a wet state.

5. The stent of claim 1, wherein a weight average molecular weight of the copolymer is between 60 and 150 kDa.

6. The stent of claim 1, wherein any of the crowns have a maximum crown angle of between about 90 degrees and 115 degrees when the scaffold has the expanded diameter.

7. The stent of claim 1, wherein the crystallinity of the scaffold is 20% to 30%.

8. The stent of claim 1, wherein the crystallinity of the scaffold is 10% to 40%.

9. A stent, comprising:

a scaffold formed from a polymer tube and configured for being crimped to a balloon,

the scaffold having a pattern of interconnected struts and the scaffold having an expanded diameter when expanded from a crimped state by the balloon,

wherein the scaffold comprises a random copolymer of poly(L-lactide) (PLLA) and polycaprolactone (PCL) and the PCL is 1 to 75 wt % or mol % of the copolymer,

wherein the crystallinity of the scaffold is 20% to 30%,

wherein the scaffold pattern includes a plurality of undulating rings having crowns and longitudinally extending links connecting one ring to another adjacent ring, wherein the crowns include W-crowns, Y-crowns, and free crowns not connected to a link, wherein the scaffold pattern forms closed cells,

wherein a first link connects a first ring to an adjacent ring, the first link forms with the first ring a W-crown, and the first link forms with the adjacent ring a Y-crown;

wherein the first ring, the adjacent ring, and the first link form repeating W-V closed cells,

wherein the W-V cells have three free crowns between a W-crown and a Y-crown.

10. The stent of claim 9, wherein the glass transition temperature of the random copolymer is between 30°

C. and 50°

C.

11. The stent of claim 9, wherein when the scaffold self-expands in a lumen, it exerts an outward residual force on the lumen wall.

12. The stent of claim 9, wherein the PCL is 15 to 50 wt % or mol % of the copolymer.

13. The stent of claim 9, wherein the PCL is 15 to 30 wt % or mol % of the copolymer.

14. The stent of claim 9, wherein the PCL is 50 to 75 wt % or mol % of the copolymer.

15. The stent of claim 9, wherein the PCL is 1 to 5 wt % or mol % of the copolymer.

16. The stent of claim 9, wherein the PCL is less than 15 wt % or mol % of the copolymer.

17. The stent of claim 9, wherein the scaffold attains greater than about 80% of the expanded diameter after being crushed to at least 50% of the expanded diameter.

18. The stent of claim 9, wherein the PCL is 3 to 10 wt % or mol % of the copolymer.