Methods of forming polymer-bioceramic composite medical devices with bioceramic particles

• US 8,425,591 B1
• Filed: 06/11/2007
• Issued: 04/23/2013
• Est. Priority Date: 06/11/2007
• Status: Expired due to Fees

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Inventors: Wang, Yunbing, Gale, David C.
• Primary Examiner(s): Sweet, Thomas J
• Assistant Examiner(s): Mathew, Seema
• Application Number:
  US11/811,698
• Time in Patent Office: 2,143 Days
• Field of Search: 623/1.15, 623/1.38, 623/1.34, 623/1.44, 623/1.42, 424/426, 430/269
• US Class Current: 623/1.42
• CPC Class Codes: A61F 2/06 Blood vessels
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61L 31/126 containing carbon fillers
• CPC Class Codes: A61L 31/127 containing fillers of phosphorus-containing inorganic materials
• CPC Class Codes: A61L 31/128 containing other specific inorganic fillers not covered by A61L31/126 or A61L31/127
• CPC Class Codes: C08L 67/04 Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence

Abstract

Methods and devices relating to polymer-bioceramic composite implantable medical devices are disclosed.

Claims

1. A method for fabricating an implantable medical device comprising:

forming a suspension solution comprising polymer and a non-reactive surface modifier dissolved in a fluid and bioceramic particles dispersed in the fluid;

removing all or substantially all of the fluid to form a composite mixture, wherein the composite mixture comprises the bioceramic particles dispersed within the polymer, wherein the non-reactive surface modifier reduces the agglomeration of the bioceramic particles in the suspension solution, during formation of the composite mixture, or both; and

fabricating an implantable medical device from the composite mixture;

wherein the non-reactive surface modifier comprises stearic acid.

2. The method of claim 1, wherein the fluid is a solvent.

3. The method of claim 2, wherein the solvent is selected from the group consisting of toluene, chloroform, and combinations thereof.

4. The method of claim 1, wherein removing all or substantially all of the fluid comprises adding a poor solvent for the polymer to the suspension thereby precipitating the composite mixture, and subsequently filtering out the precipitated composite mixture.

5. The method of claim 1, wherein removing all or substantially all of the fluid comprises evaporating the fluid.

6. The method of claim 1, wherein removing all or substantially all of the fluid comprises evaporating the fluid at high vacuum.

7. The method of claim 1, wherein the bioceramic particles comprise at least one of the group consisting of alumina, zirconia, apatites, calcium phosphates, silica based glasses, glass ceramics, and pyrolytic carbons.

8. The method of claim 1, wherein the bioceramic particles comprise at least one of the group consisting of hydroxyapatite (Ca₁₀(PO₄)₆(OH)₂), floroapatite (Ca₁₀(PO₄)₆F₂), carbonate apatite (Ca₁₀(PO₄)₆CO₃), tricalcium phosphate (Ca₃(PO₄)₂), octacalcium phosphate (Ca₈H₂(PO₄)₆·

5H₂O), calcium pyrophosphate (Ca₂P₂O₇-2H₂O), tetracalcium phosphate (Ca₄P₂O₉), and dicalcium phosphate dihydrate (CaHPO₄·

2H₂O).

9. The method of claim 1, wherein the polymer of the suspension solution is poly(L-lactic acid), poly(D, L-lactic acid), poly(lactide-co-glycolide), or any combination thereof.