Method of manufacturing antimicrobial implants of polyetheretherketone
Inventors
Crudden, Joseph J. • Johns, Derrick
Assignees
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Publication Number
US-9132576-B2
Publication Date
2015-09-15
Expiration Date
Abstract
Methods of fabricating implantable medical devices, preferably with PEEK, having antimicrobial properties, are disclosed. The antimicrobial effect is produced by incorporating ceramic particles containing antimicrobial metal cations into molten PEEK resin, which is subsequently allowed to cool and set in its final shape achieved by injection molding, cutting and machining or other techniques.
Core Innovation
The invention provides a method of making a load-bearing antimicrobial implant by drying polyetheretherketone resin to a residual moisture content of less than 0.1% moisture by weight, heating the dried polyetheretherketone resin to a temperature effective to melt the resin, blending into the molten resin a metal zeolite that has been dried to a residual moisture content of less than 0.1% moisture by weight, and cooling the blend. The blend is then formed into the implant and the surface of the implant is roughened.
The approach emphasizes incorporating antimicrobial metal cations within metal zeolite/zeolite ceramic particles, including antimicrobial metal cations such as silver and other metals listed such as copper, zinc, mercury, tin, lead, gold, bismuth, cadmium, chromium, and thallium. Claimed processing and material control relate to removing moisture to prevent voids, PEEK decomposition, and oxidation of incorporated metals during making of the implant.
In an antimicrobial implant context, the invention reports zeolite loading ranges for metal zeolite in PEEK, dispersion assessment and quantification of embedded and eluated antimicrobial metal, and antimicrobial efficacy against E. coli and Staphylococcus aureus. Additional reported characteristics include radiopacity at low silver-zeolite loading and improved osteoblast attachment described as arising from negatively charged zeolite silicates.
Claims Coverage
The partial content provides one independent claim and does not provide additional independent claim texts beyond clm-00001. The independent claim covers five main inventive operations or features: very low-moisture drying of PEEK, melting of dried PEEK, blending dried metal zeolite into molten PEEK, cooling and forming into a load-bearing antimicrobial implant, and roughening the implant surface.
Drying PEEK to less than 0.1% moisture by weight
Drying polyetheretherketone resin to a residual moisture content of less than 0.1% moisture by weight.
Melting dried polyetheretherketone resin
Heating the dried polyetheretherketone resin to a temperature effective to melt the resin.
Blending dried metal zeolite into molten PEEK
Blending into the molten resin a metal zeolite that has been dried to a residual moisture content of less than 0.1% moisture by weight.
Cooling, forming into a load-bearing antimicrobial implant
Cooling the blend and forming the blend into the implant.
Roughening the implant surface
Roughening the surface of the implant.
Based on the partial content, claim coverage centers on producing a load-bearing antimicrobial implant by combining very low-moisture PEEK with a very low-moisture metal zeolite, melting and blending, cooling and forming into the implant, and roughening the implant surface.
Stated Advantages
Prevents voids, PEEK decomposition, and oxidation of incorporated metals.
Provides antimicrobial efficacy with up to approximately six-log reduction against E. coli and S. aureus at the described zeolite loading.
Provides radiopacity at low silver-zeolite loading.
Improves osteoblast cell attachment via negatively charged zeolite silicates.
Documented Applications
Load-bearing antimicrobial orthopedic implant made using polyetheretherketone with antimicrobial metal zeolite, including spinal or cervical spacer contexts.
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