Ultrahigh ductility, novel Mg—Li based alloys for biomedical applications

Patent metadata

Field	Value
Publication number	US-11077227-B2
Application number	US-201515532149-A
Country	US
Kind code	B2
Filing date	Dec 9, 2015
Priority date	Dec 12, 2014
Publication date	Aug 3, 2021
Grant date	Aug 3, 2021

Abstract

The invention relates to compositions including magnesium-lithium alloys containing various alloying elements suitable for medical implant devices. The devices may be constructed of the compositions or have applied thereto a coating formed therefrom. Within the structure of the magnesium-lithium alloy, there is a co-existence of alpha and beta phases. The invention also relates to methods of preparing the magnesium-lithium alloys and articles, such as medical implant devices, for use in medical applications, such as but not limited to, orthopedic, dental, craniofacial and cardiovascular surgery.

First claim

The invention claimed is:

1. A biodegradable medical implant device composed of a ductile, dual phase magnesium-based alloy, consisting of:
the dual phase-magnesium-based alloy having co-existing alpha and beta phases, selected from the group consisting of:
(i) 9.00% by weight lithium based on total weight of the alloy;
0.96% by weight zinc based on total weight of the alloy;
0.01% by weight aluminum based on total weight of the alloy; and
a remainder of magnesium, or
(ii) 8.99% by weight lithium based on total weight of the alloy;
0.87% by weight zinc based on total weight of the alloy;
1.07% by weight aluminum based on total weight of the alloy; and
a remainder of magnesium, or

(iii) 6.11% by weight lithium based on total weight of the alloy;
0.92% by weight zinc based on total weight of the alloy;
0.04% by weight aluminum based on total weight of the alloy; and
a remainder of magnesium; and

optionally, an active agent,
wherein each of the alloys (i), (ii) and (iii) exhibits an elongation of about 48%, about 50% and about 45%, respectively.

2. The medical implant device of claim 1 , consisting of the active agent.

3. A coated, biodegradable medical implant device, consisting essentially of:
a substrate; and
a coating deposited on the substrate, the coating consisting of:
a ductile, dual phase-magnesium-based alloy having co-existing alpha and beta phases, selected from the group consisting of:
(i) 9.00 by weight lithium based on total weight of the alloy;
0.96% by weight zinc based on total weight of the alloy;
0.01% by weight aluminum based on total weight of the alloy; and
a remainder of magnesium, or
(ii) 8.99% by weight lithium based on total weight of the alloy;
0.87% by weight zinc based on total weight of the alloy;
1.07% by weight aluminum based on total weight of the alloy; and
a remainder of magnesium, or

(iii) 6.11% by weight lithium based on total weight of the alloy;
0.92% by weight zinc based on total weight of the alloy;
0.04% by weight aluminum based on total weight of the alloy; and

a remainder of magnesium,

wherein each of the alloys (i), (ii) and (iii) exhibits an elongation of about 48%, about 50% and about 45%, respectively.

4. The coated medical implant device of claim 3 , wherein the plasticity and ductility of said device exceeds plasticity and ductility of devices composed of magnesium containing alloys absent lithium.

5. The coated medical implant device of claim 3 , wherein said device is effective for use in orthopedic, dental, craniofacial and cardiovascular surgeries.

6. The coated medical implant device of claim 3 , wherein the said device is effective to release lithium ions as a therapeutic drug eluting device.

7. The biodegradable medical implant device of claim 1 , wherein the device is selected from the group consisting of a stent, suture, wire or staple.

8. The biodegradable medical implant device of claim 3 , wherein the device is selected from the group consisting of a stent, suture, wire or staple.

Assignees

• Univ Of Pittsburgh—Of The Commonwealth System Of Higher Education

Inventors

• Kumta Prashant N
• Wu Jingyao
• Velikokhatnyi Oleg

Classifications

• A61L27/047 Primary

  Other specific metals or alloys not covered by A61L27/042 - A61L27/045 or A61L27/06 · CPC title

• A61L31/088

  Other specific inorganic materials not covered by A61L31/084 or A61L31/086 · CPC title

• A61L31/022

  Metals or alloys · CPC title

• A61L27/306

  Other specific inorganic materials not covered by A61L27/303 - A61L27/32 · CPC title

• A61L27/54

  Biologically active materials, e.g. therapeutic substances {(A61L27/227 takes precedence)} · CPC title