ULTRAHIGH DUCTILITY, NOVEL Mg-Li BASED ALLOYS FOR BIOMEDICAL APPLICATIONS

Patent metadata

Field	Value
Publication number	US-2021369914-A1
Application number	US-202117381445-A
Country	US
Kind code	A1
Filing date	Jul 21, 2021
Priority date	Dec 12, 2014
Publication date	Dec 2, 2021
Grant date	—

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

1 . A method for preparing a coated medical implant device, comprising:
obtaining a substrate structured for implanting into a body; forming a coating composition comprising an alloy, comprising:
alloying from about 5% by weight to about 11% by weight of lithium and a remainder of magnesium based on the total weight of the alloy,
wherein the alloy is structured to exhibit a co-existence of alpha and beta phases, and wherein the alloy exhibits one or more of improved ductility and elasticity; and applying the coating composition onto a surface of the substrate to form a coating thereon.

2 . The method of claim 1 , wherein the alloying step further comprises one or more alloying elements selected from the group consisting of iron, zirconium, manganese, calcium, yttrium, rare earth elements, aluminum, strontium, copper, silver, silicon, sodium, potassium, cerium and zinc.

3 . The method of claim 1 , further comprising adding an active agent to the coating composition.

4 . The method of claim 1 , further comprising using the coated medical implant device in orthopedic, dental, craniofacial and cardiovascular surgeries.

5 . The method of claim 1 , wherein the coated medical implant device releases lithium ions as a therapeutic drug eluting device.

6 . The method of claim 1 , wherein in the alloying step the lithium is present in an amount of 9.00% and the alloying step further comprises 0.96% by weight zinc and 0.01% by weight aluminum, with the remainder of magnesium based on the total weight of the alloy.

7 . The method of claim 1 , wherein in the alloying step the lithium is present in an amount of 8.99% and the alloying step further comprises 0.87% by weight zinc and 1.07% by weight aluminum, with the remainder of magnesium based on the total weight of the alloy.

8 . The method of claim 1 , wherein in the alloying step the lithium is present in an amount of 6.11% and the alloying step further comprises 0.92% by weight zinc and 0.04% by weight aluminum, with the remainder of magnesium based on the total weight of the alloy.

9 . The method of claim 1 , wherein the alloying step comprises:
high energy mechanical alloying of the lithium and the magnesium; followed by uniaxial or isostatic compaction; and followed by sintering.

10 . A method for preparing a medical implant device, comprising:
fabricating a substrate structured for implanting into a body, comprising:
forming an alloy, comprising:
melting from about 5% by weight to about 11% by weight of lithium and a remainder of magnesium based on the total weight of the alloy,

wherein the alloy is structured to exhibit a co-existence of alpha and beta phases, and wherein the alloy exhibits one or more of improved ductility and elasticity;
casting the alloy to form a casted alloy; and
extruding the casted alloy to form the substrate in an extruded form.

11 . The method of claim 10 , wherein the melting step further comprises one or more alloying elements selected from the group consisting of iron, zirconium, manganese, calcium, yttrium, rare earth elements, aluminum, strontium, copper, silver, silicon, sodium, potassium, cerium and zinc.

12 . The method of claim 10 , further comprising adding an active agent to the alloy.

13 . The method of claim 10 , further comprising using the medical implant device in orthopedic, dental, craniofacial and cardiovascular surgeries.

14 . The method of claim 10 , wherein the medical implant device releases lithium ions as a therapeutic drug eluting device.

15 . The method of claim 10 , wherein in the melting step the lithium is present in an amount of 9.00% and the melting step further comprises 0.96% by weight zinc and 0.01% by weight aluminum, with the remainder of magnesium based on the total weight of the alloy.

16 . The method of claim 10 , wherein in the melting step the lithium is present in an amount of 8.99% and the melting step further comprises 0.87% by weight zinc and 1.07% by weight aluminum, with the remainder of magnesium based on the total weight of the alloy.

17 . The method of claim 10 , wherein in the melting step the lithium is present in an amount of 6.11% and the melting step further comprises 0.92% by weight zinc and 0.04% by weight aluminum, with the remainder of magnesium based on the total weight of the alloy.

18 . The method of claim 10 , wherein the melting step comprises:
high energy mechanical alloying of the lithium and the magnesium; followed by uniaxial or isostatic compaction; and followed by sintering.

Assignees

• Univ Pittsburgh Commonwealth Sys 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

• A61L31/022

  Metals or alloys · CPC title

• C22C23/00

  Alloys based on magnesium · CPC title

• A61L31/088

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

• A61L27/54

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