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Bioabsorbable scaffolds made from composites

a composite material and bioabsorbable technology, applied in the field of polymer medical devices, can solve the problems of difficult treatment, adverse or even toxic side effects, and the stenosis remains a significant problem, and achieve the effect of reducing the risk of restenosis

Inactive Publication Date: 2014-02-06
ABBOTT CARDIOVASCULAR
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The present invention provides stents made from a composite material that includes a polymer and bioceramic particles dispersed throughout the polymer. The bioceramic particles can be nanoparticles. The stents made from this composite material have improved properties such as improved mechanical strength, flexibility, and drug-release capabilities. The method of making the stents involves combining the polymer, bioceramic particles, and a specific dispersant, forming a tube, and then shaping the tube into a scaffold. The stents made from this composite material can be used to treat various medical conditions such as blood vessel occlusions.

Problems solved by technology

Yet, restenosis remains a significant problem.
When restenosis does occur in the stented segment, its treatment can be challenging, as clinical options are more limited than for those lesions that were treated solely with a balloon.
Effective concentrations at the treated site require systemic drug administration which often produces adverse or even toxic side effects.
However, there are several challenges making a bioabsorbable polymeric stent.
Another challenge is tailoring bioabsorbable stents to meet these varying requirements.

Method used

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  • Bioabsorbable scaffolds made from composites
  • Bioabsorbable scaffolds made from composites
  • Bioabsorbable scaffolds made from composites

Examples

Experimental program
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Effect test

examples

[0116]1. Scaffold Preparation from PLLA / P4HB / Bioceramic Composite

Step 1: PLLA / P4HB / Bioceramic Composite Preparation

[0117]In this experiment, a PLLA / P4HB / bioceramic composite with P4HB and bioceramic content at 10%, 2%, is prepared through twin screw extrusion at 420° F. with screw speed at 50 rpm.

Step 2: Scaffold Preparation

[0118]2a). Tubing extrusion and expansion: PLLA / P4HB / bioceramic composite is extruded and expanded. The temperature for extrusion is set at 420° F., the expansion temperature is 205° F. and the expansion pressure is 110 psi. The extruded tube of PLLA / P4HB / bioceramic has an ID at 0.20″ and OD at 0.64″, while the expanded tube has ID at 0.124″ and OD at 0.136″.

2b). The expanded PLLA / P4HB / bioceramic composite tube is laser cut, crimped, and sterilized for testing.

2. Scaffold Preparation from PLLA / PLLA-b-PCL / Bioceramic / LLA Composite

Step 1: PLLA / PLLA-b-PCL / Bioceramic / LLA Composite Preparation

[0119]In this experiment, PLLA / PLLA-b-PCL / bioceramic / LLA composite with PLLA-...

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Abstract

Bioabsorbable scaffolds made at least in part of a poly(L-lactide)-based composite are disclosed. The composite includes poly(4-hydroxybutyrate) or poly(L-lactide)-b-polycaprolactone block copolymer, which increases the fracture toughness or fracture resistance of the scaffold. The composite can further include bioceramic particles, L-lactide monomer, or both dispersed throughout the composite. The bioceramic particles improve the radial strength and stiffness of the scaffold. The L-lactide monomer is used to control the absorption rate of the scaffold.

Description

[0001]This application is a continuation of U.S. patent application Ser. No. 13 / 107,643 filed May 13, 2011 and is incorporated by reference herein.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]This invention relates polymeric medical devices, in particular, bioabsorbable stents or stent scaffoldings.[0004]2. Description of the State of the Art[0005]This invention relates to radially expandable endoprostheses, that are adapted to be implanted in a bodily lumen. An “endoprosthesis” corresponds to an artificial device that is placed inside the body. A “lumen” refers to a cavity of a tubular organ such as a blood vessel. A stent is an example of such an endoprosthesis. Stents are generally cylindrically shaped devices that function to hold open and sometimes expand a segment of a blood vessel or other anatomical lumen such as urinary tracts and bile ducts. Stents are often used in the treatment of atherosclerotic stenosis in blood vessels. “Stenosis” refers to a narrow...

Claims

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Application Information

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Patent Type & Authority Applications(United States)
IPC IPC(8): A61F2/82
CPCA61F2/82A61F2/915A61F2002/91575A61F2210/0004A61L31/127A61L31/128A61L31/148C08L67/04A61F2210/0076A61F2230/0054C08K3/013
Inventor WANG, YUNBING
Owner ABBOTT CARDIOVASCULAR