Composite scaffold with post anchor for the repair and regeneration of tissue

• US 6,626,950 B2
• Filed: 06/28/2001
• Issued: 09/30/2003
• Est. Priority Date: 06/28/2001
• Status: Expired due to Term

• Current Assignee: Ethicon Incorporated (Johnson & Johnson)
• Original Assignee: Ethicon Incorporated (Johnson & Johnson)
• Inventors: Li, Yufu, Brown, Kelly R., Zimmerman, Mark C.
• Primary Examiner(s): Lucchesi, Nicholas D.
• Assistant Examiner(s): Hamilton, Lalita M.
• Application Number:
  US09/893,813
• Publication Number:
  US 20030004578A1
• Time in Patent Office: 824 Days
• Field of Search: 623/13.14, 623/13.15, 623/20.17, 623/23.56, 623/23.58, 623/23.72, 623/23.73, 623/23.74, 623/23.75, 623/23.76, 424/427, 424/425, 424/426, 435/41
• US Class Current: 623/23.72
• CPC Class Codes: A61B 17/00491 Surgical glue applicators surgical adhesives A61L24/00; two-component delivery syringes A61M5/19
• CPC Class Codes: A61B 2017/00004 (bio)absorbable, (bio)resorbable, resorptive for implantable prostheses A61F2210/0004
• CPC Class Codes: A61B 2017/0646 for insertion into cartillege, e.g. meniscus
• CPC Class Codes: A61F 2/08 Muscles; Tendons; Ligaments sutures A61B17/04
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• CPC Class Codes: A61F 2/30749 Fixation appliances for connecting prostheses to the body
• CPC Class Codes: A61F 2/30756 Cartilage endoprostheses A61F2/3603 takes precedence
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• CPC Class Codes: A61F 2/3872 Meniscus for implantation between the natural bone surfaces
• CPC Class Codes: A61F 2/442 Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• CPC Class Codes: A61F 2002/2817 Bone stimulation by chemical reactions or by osteogenic or biological products for enhancing ossification, e.g. by bone morphogenetic or morphogenic proteins [BMP] or by transforming growth factors [TGF]
• CPC Class Codes: A61F 2002/30011 differing in porosity
• CPC Class Codes: A61F 2002/30028 differing in tissue ingrowth capacity, e.g. made from both ingrowth-promoting and ingrowth-preventing parts
• CPC Class Codes: A61F 2002/30032 differing in absorbability or resorbability, i.e. in absorption or resorption time
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30069 elastomeric
• CPC Class Codes: A61F 2002/30233 Stepped cylinders, i.e. having discrete diameter changes
• CPC Class Codes: A61F 2002/30563 having elastic means or damping means, different from springs, e.g. including an elastomeric core or shock absorbers
• CPC Class Codes: A61F 2002/30677 Means for introducing or releasing pharmaceutical products, e.g. antibiotics, into the body
• CPC Class Codes: A61F 2002/30751 for attaching cartilage scaffolds to underlying bone
• CPC Class Codes: A61F 2002/30762 : Means for culturing cartilage
• CPC Class Codes: A61F 2002/30766 : Scaffolds for cartilage ingrowth and regeneration
• CPC Class Codes: A61F 2002/30878 : with non-sharp protrusions, for instance contacting the bone for anchoring, e.g. keels, pegs, pins, posts, shanks, stems, struts
• CPC Class Codes: A61F 2002/30879 : Ribs
• CPC Class Codes: A61F 2002/30904 : serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2002/30957 : using a positive or a negative model, e.g. moulds
• CPC Class Codes: A61F 2002/30971 : Laminates, i.e. layered products
• CPC Class Codes: A61F 2002/4631 : the prosthesis being specially adapted for being cemented
• CPC Class Codes: A61F 2210/0004 : bioabsorbable
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2250/0023 : differing in porosity
• CPC Class Codes: A61F 2250/003 : differing in adsorbability or resorbability, i.e. in adsorption or resorption time
• CPC Class Codes: A61F 2250/0051 : differing in tissue ingrowth capacity, e.g. made from both ingrowth-promoting and ingrowth-preventing parts
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures
• CPC Class Codes: A61F 2310/00221 : containing calcia or calcium oxide
• CPC Class Codes: A61F 2310/00293 : containing a phosphorus-containing compound, e.g. apatite
• CPC Class Codes: A61F 2310/00365 : Proteins; Polypeptides; Degradation products thereof
• CPC Class Codes: A61F 2310/0097 : Coating or prosthesis-covering structure made of pharmaceutical products, e.g. antibiotics
• CPC Class Codes: A61L 27/425 : of phosphorus containing material, e.g. apatite
• CPC Class Codes: A61L 27/46 : with phosphorus-containing inorganic fillers
• CPC Class Codes: A61L 27/56 : Porous materials, e.g. foams or sponges
• CPC Class Codes: B29C 44/1214 : Anchoring by foaming into a preformed part, e.g. by penetrating through holes anchoring by moulding in general B29C37/0078; outsert moulding B29C45/14344, B29C70/74

Abstract

A prosthetic implant having a tissue scaffold and a fixation device with a scaffold support and an anchoring post. The anchoring post extends from a surface of the scaffold support at a selected angle with the scaffold support embedded within the scaffold. The scaffold has a porous ceramic phase and a porous polymer phase. The polymer is foamed while in solution that is infused in the pores of the ceramic to create a interphase junction of interlocked porous materials and embedding the scaffold support portion of the fixation device. The preferred method for foaming is by lyophilization. The scaffold may be infused or coated with a variety of bioactive materials to induce ingrowth or to release a medicament. The mutilayered porous scaffold can mimic the morphology of an injured tissue junction with a gradient morphology and cell composition.

Claims

1. A prosthetic implant, comprising:

a composite tissue scaffold having a ceramic layer with a first plurality of pores and a polymer layer with a second plurality of pores, said polymer attached to said ceramic at an interphase region, said polymer infused at least partially into said first plurality of pores in said interphase region at least one of said polymer layer and said ceramic layer being biodegradable; and

a fixation device with a scaffold support and an anchoring post, said anchoring post extending from a surface of said scaffold support at a selected angle, said anchoring post insertable into a receptacle formed in tissue, said scaffold support embedded within said scaffold.

2. The implant of claim 1, wherein a portion of said second plurality of pores communicate at least partially with said first plurality of pores in said interphase region.

3. The implant of claim 2, wherein said ceramic has a hole therein, said anchoring post extending through said hole, said scaffold support abutting against said ceramic proximate said hole, said scaffold support being larger than said hole, preventing said scaffold support from passing through said hole, said interphase region extending proximate to a periphery of said scaffold support.

4. The implant of claim 3, wherein said ceramic has a countersunk area disposed about said hole, said scaffold support being at least partially contained within said countersunk area.

5. The implant of claim 4, wherein said scaffold support has at least one opening extending therethrough, said at least one opening permitting said polymer to extend therethrough.

6. The implant of claim 1, further including a mechanical reinforcement embedded in said polymer, said mechanical reinforcement selected from the group consisting of films, scrims, woven textiles, non-woven textiles, knitted textiles, braided textiles and trusses.

7. The implant of claim 1, further including fillers within said polymer selected from the group consisting of growth factors and therapeutic materials.

8. The implant of claim 1, further including living cells residing on a surface of said scaffold.

9. The implant of claim 1, wherein said ceramic is selected from the group consisting of hydroxyapatite, tricalcium phosphate, tetracalcium phosphate, fluoroapatite, magnesium calcium phosphate, calcium sulfate, calcium fluoride, calcium oxide and calcium carbonate.

10. The implant of claim 1, wherein said polymer is selected from the group consisting of collagen, elastin, hyaluronic acid, chitin and alginate.

11. The implant of claim 1, wherein said polymer is selected from the group consisting of aliphatic polyester homopolymers and aliphatic polyester copolymers.

12. The implant of claim 11, wherein said polymer is selected from the group consisting of lactic acid, lactide mixtures of L-, D-, meso and D,L lactides, glycolic acid, glycolide, epsilon-caprolactone, p-dioxanone (1,4-dioxan-2-one) and trimethylene carbonate (1,3-dioxan-2-one).

13. The implant of claim 1, wherein said polymer is an aliphatic polyester elastomeric copolymer.

14. The implant of claim 13, wherein said copolymer is formed from epsilon-caprolactone and glycolide in a mole ratio of from about 35:

65 to about 65;

35.

15. The implant of claim 13, wherein said copolymer is formed from epsilon-caprolactone and glycolide in a mole ratio of from about 45:

55 to about 35;

65.

16. The implant of claim 13, wherein said copolymer is formed from epsilon-caprolactone and lactide selected from the group consisting of L-lactide, D-lactide and lactic acid copolymers in a mole ratio of epsilon-caprolactone to lactide of from about 35:

65 to about 65;

35.

17. The implant of claim 13, wherein said copolymer is formed from epsilon-caprolactone and lactide selected from the group consisting of L-lactide, D-lactide and lactic acid copolymers in a mole ratio of epsilon-caprolactone to lactide of from about 45:

55 to about 30;

70.

18. The implant of claim 13, wherein said copolymer is formed from epsilon-caprolactone and lactide selected from the group consisting of L-lactide, D-lactide and lactic acid copolymers in a mole ratio of epsilon-caprolactone to lactide of from about 95:

5 to about 85;

15.

22. The implant of claim 1, wherein said scaffold support has a generally flat first surface and a second surface substantially parallel to said first surface, said anchoring post extending from said second surface, said ceramic layer being juxtaposed next to said polymer layer with said scaffold support captured therebetween, said ceramic layer being disposed proximate said second surface and said polymer layer disposed proximate said first surface.

23. The implant of claim 22, wherein at least one of said ceramic layer and said polymer layer has a hollow therein for at least partially receiving said scaffold support.

24. The implant of claim 22, wherein said ceramic layer and said polymer layer each have a hollow therein for at least partially receiving said scaffold support.

19. A method for making a prosthetic implant having a tissue scaffold and an embedded fixation device with a scaffold support and an anchoring post, comprising the steps of:

a) providing a porous ceramic body with a first set of pores and a hole extending therethrough;

b) providing a polymer solution;

c) inserting the anchoring post of the fixation device through the hole in the ceramic body such that the scaffold support contacts the ceramic body forming a first subassembly;

d) placing the support scaffold and the ceramic body of the subassembly in contact with the polymer solution;

e) permitting the polymer solution to at least partially infuse into pores in the ceramic body; and

f) foaming the polymer solution to produce a polymer foam with a second set of pores, the polymer foam interlocking with the ceramic body where the polymer solution was permitted to infuse into the ceramic body and embedding the scaffold support within the resulting conjoined composite, with at least a portion of the first set of pores communicating with at least a portion of the second set of pores.

20. The method of claim 19, wherein said step of foaming is by lyophilization.

21. The method of claim 20, wherein said polymer solution is poured into a mold with a hollow well and an implant support overarching the well, and further comprising the step of suspending the implant from the implant support such that the subassembly is submerged in the polymer solution to a selected level.