Method of manufacturing antimicrobial implants of polyetheretherketone
Inventors
Crudden, Joseph J. • HAFIZ, JAMI • Deaton, James E. • Pepper, John R. • Johns, Derrick
Assignees
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Publication Number
US-8840914-B2
Publication Date
2014-09-23
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 relates to a method of making a load bearing antimicrobial implant using polyetheretherketone (PEEK) and a metal zeolite comprising silver zeolite. The method includes drying polyetheretherketone resin to a residual moisture content of less than 0.1% moisture by weight, and heating the dried resin to a temperature effective to melt the resin.
A molten PEEK blend is formed by blending the metal zeolite comprising silver zeolite into the molten resin, followed by cooling the blend. The cooled blend is then formed into the implant, with antimicrobial metal-cation ceramic particles incorporated into the molten PEEK and processed to support dispersion and avoid voids and oxidation.
The disclosed processing includes controlling moisture and handling conditions to reduce residual moisture and support antimicrobial performance, while incorporating silver zeolite at specified levels. The dispersion of the particles and the silver loading and elution are verified, and antimicrobial efficacy is reported for reductions against E. coli and S. aureus, including MRSA, after exposure periods.
Claims Coverage
The partial content provides one independent claim, clm-00001. Its coverage focuses on the core processing sequence for a load bearing antimicrobial implant using dried PEEK and a silver-zeolite metal zeolite, followed by cooling and forming.
Drying PEEK to less than 0.1% residual moisture
Drying polyetheretherketone resin to a residual moisture content of less than 0.1% moisture by weight.
Melting dried PEEK at an effective melting temperature
Heating the dried polyetheretherketone resin to a temperature effective to melt the resin.
Blending molten PEEK with a metal zeolite comprising silver zeolite
Blending into the molten resin a metal zeolite comprising silver zeolite.
Cooling and forming the silver zeolite/PEEK blend into the implant
Cooling the blend and forming the blend into said implant.
Across the provided independent claim, the claimed inventive concept is the combination of very low residual moisture PEEK, melting, blending in a metal zeolite comprising silver zeolite, and then cooling and forming the resulting blend into a load bearing antimicrobial implant. The provided dependents further constrain drying and blending details, including zeolite loading ranges and optional formulation characteristics.
Stated Advantages
Antimicrobial efficacy, including up to about a 6-log CFU reduction against E. coli and S. aureus after 24 h.
Radiopacity at low silver-zeolite loadings.
Enhanced cell attachment due to negatively charged zeolite silicates.
Additional performance benefits associated with surface roughness monitoring/optimization for silver efficacy and osteogenic response.
Documented Applications
Load bearing antimicrobial implants made from polyetheretherketone (PEEK) incorporating antimicrobial metal-cation ceramic particles comprising silver zeolite.
Antimicrobial testing contexts against E. coli, S. aureus, and MRSA (reported as CFU reductions after exposure periods).
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