Plastic molded articles with shape memory property

• US 4,950,258 A
• Filed: 01/25/1989
• Issued: 08/21/1990
• Est. Priority Date: 01/28/1988
• Status: Expired due to Fees

• Current Assignee: JMS Company Limited
• Original Assignee: Medical Supply Depot
• Inventors: Matsuda, Takashi, Kawai, Tatsuya
• Primary Examiner(s): YASKO JR, JOHN D
• Application Number:
  US07/301,501
• Time in Patent Office: 573 Days
• Field of Search: 604/281, 604/282, 604/8, 264/230, 264/DIG. 40, 264/DIG. 41, 128/325, 128/334 R, 128/335, 128/335.5, 128/336
• US Class Current: 604/530
• CPC Class Codes: A61B 17/02 for holding wounds open; Tractors specula A61B1/32 ; drainage appliances for wounds A61M27/00
• CPC Class Codes: A61B 17/0644 penetrating the tissue, deformable to closed position
• CPC Class Codes: A61B 17/08 Wound clamps or clips, i.e. not or only partly penetrating the tissue suture bridges A61B17/0466; Devices for bringing together the edges of a wound
• CPC Class Codes: A61B 17/12 for ligaturing or otherwise compressing tubular parts of the body, e.g. blood vessels, umbilical cord specially adapted for vas deferens or fallopian tubes A61F6/20; materials for ligaturing blood vessels A61L17/00
• CPC Class Codes: A61B 17/122 Clamps or clips , e.g. for the umbilical cord for the vas deferens A61F6/206
• CPC Class Codes: A61B 17/1227 Spring clips
• CPC Class Codes: A61F 2/92 Stents in the form of a rolled-up sheet expanding after insertion into the vessel , e.g. with a spiral shape in cross-section
• CPC Class Codes: A61F 2/94 Stents retaining their form, i.e. not being deformable, after placement in the predetermined place
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• 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: A61L 2400/16 Materials with shape-memory or superelastic properties
• 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: A61M 31/002 Devices for releasing a drug at a continuous and controlled rate for a prolonged period of time artificial gland structures or devices A61F2/022; intra-uterine contraceptive devices A61F6/14; tampons for introducing into the vagina A61F13/20, A61L15/00; suppositories or bougies for intra-vaginal or intra-uterine application A61K9/02; physical forms of medicinal preparations for sustained or differential drug release A61K9/20, A61K9/50
• CPC Class Codes: B29C 61/003 characterised by the choice of material
• CPC Class Codes: C08L 67/04 Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence
• CPC Class Codes: Y10S 264/40 Processes of coiling plastics
• CPC Class Codes: Y10S 264/41 Processes of molding collapsible tubes

Abstract

Plastic molded articles having characteristic properties of both shape-memory and biodegradability and a process for preparing the same are disclosed. The molded products consist of homopolymers of lactide or glycolide or copolymers of lactide and glycolide. The molded articles of this invention are particularly useful for a variety of medical devices.

Claims

1. A molded article which can be returned to a previously memorized shape, consisting essentially of polymers selected from the group consisting of lactide homopolymers, glycolide homopolymers and copolymers of lactide and glycolide, said polymers having a shape memory property.

2. A molded article according to claim 1, wherein said polymers are copolymers containing 10-90 mol.% lactide and 90-10 mol.% glycolide.

3. A molded article according to claim 1 wherein said polymers are copolymers containing 20-80 mol.% lactide and 80-20 mol.% glycolide.

4. A molded article according to claim 1 wherein the article is a clip for tissue suturing.

5. A molded article according to claim 1, wherein the article is a device for preventing blood vessel obstruction.

6. A molded article according to claim 1, wherein the article is a device for expanding a restricted blood vessel.

7. A molded article according to claim 1, wherein the article is an actuator for releasing a drug from a medical capsule.

8. A molded article according to claim 1, wherein the article is a clip for a cerebral aneurysm.

9. A molded article according to claim 1, wherein the article comprises rings for attachment to the ends of an artificial blood vessel.

10. A molded article according to claim 1, wherein the article is a hemostatic clip.

11. A process for preparing a molded article according to claim 1, comprising the steps of:

molding a polymer selected from the groups consisting of lactide homopolymers, glycolide homopolymers and copolymers of lactide and glycolide into an article of a desired shape;

deforming the molded article into another shape by heat-softening; and

cooling the deformed article to cause the article to harden.

12. A process for preparing a molded article according to claim 1, comprising the steps of:

molding a polymer selected from the lactide homopolymers, glycolide homopolymers and copolymers of lactide and glycolide into an article of a desired shape;

heating the article in the desired shape for a prescribed period of time;

cooling the article;

deforming the molded article into another shape by heat softening at a temperature lower than said first heating; and

cooling the deformed article to cause the article to harden.