Article made of lactic acid polymer capable of being employed particularly as a biodegradable prosthesis and process for its manufacture

• US 5,007,939 A
• Filed: 11/07/1988
• Issued: 04/16/1991
• Est. Priority Date: 11/19/1987
• Status: Expired due to Fees

• Current Assignee: Solvay & CIE
• Original Assignee: Solvay & CIE
• Inventors: Ghyselinck, Philippe, Delcommune, Luc
• Primary Examiner(s): Cannon, Alan W.
• Application Number:
  US07/269,879
• Time in Patent Office: 890 Days
• Field of Search: 128/335.5, 623/16, 623/66, 525/410, 525/415, 528/354, 606/77
• US Class Current: 525/415
• CPC Class Codes: A61L 27/18 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: B29C 48/00 Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor extrusion blow-moulding B29C49/04
• CPC Class Codes: B29C 48/03 characterised by the shape of the extruded material at extrusion
• CPC Class Codes: B29C 55/30 Drawing through a die pultrusion B29C70/52
• CPC Class Codes: B29C 71/02 Thermal after-treatment B29C71/0063 and B29C71/0072 take precedence
• CPC Class Codes: C08L 67/04 Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence
• CPC Class Codes: Y10S 623/926 Synthetic

Abstract

Article made of lactic acid polymer capable of being employed particulaly as a biodegradable prosthesis exhibiting at 23° C. a tensile regidity modulus higher than 5000 MPa and a tensile resilience higher than 500 kJ/m² and a heat shrinkage of less than 50% at 130° C.

The article is produced by forging a blank at a temperature of between 80° and 170° C., with a draw ratio of 200 to 1000%.

Claims

1. A biodegradable prosthesis comprising a molecularly oriented lactic acid polymer exhibiting at 23°

C. a tensile rigidity modulus higher than 5000 MPa and a tensile resilience higher than 500 kJ/m².

2. The biodegradable prosthesis according to claim 1, wherein said molecularly oriented lactic acid polymer additionally exhibits a heat shrinkage of less than 15% at 130°

C.

3. The biodegradable prosthesis according to claim 1, wherein said molecularly oriented lactic acid polymer is a homopolymer of L-lactic acid.

4. The biodegradable prosthesis according to claim 1, wherein said molecularly oriented lactic acid polymer has an average molecular weight greater than 250,000.

5. The biodegradable prosthesis according to claim 1, wherein said molecularly oriented lactic acid polymer has an average molecular weight greater than 400,000.

6. The biodegradable prosthesis according to claim 1, wherein said molecularly oriented lactic acid polymer exhibits at 23°

C. a tensile rigidity modulus higher than 7,500 MPa.

7. The biodegradable prosthesis according to claim 1, wherein said molecularly oriented lactic acid polymer exhibits a tensile resilience higher than 3,000 kJ/m².

8. The biodegradable prosthesis according to claim 1, wherein said molecularly oriented lactic acid polymer is produced by extruding a blank made of lactic acid polymer at a temperature between about 170°

and 250°

C., heat-aging the extruded blank at a temperature between about 80° and

170°

C., and then drawing the aged blank to between about 200 and 1,000%.

9. The biodegradable prosthesis according to claim 8, wherein said molecularly oriented lactic acid polymer is annealed under tension at a temperature of at least about 130°

C.