Comparison of microstructure and tensile behavior of hydroxyapatite-coated PEEK meshes and cellulose-based fabrics and mats

Abstract

Polymeric biomaterials, such as polyether ether ketone (PEEK) and cellulose, have been explored as scaffolds for bone tissue engineering in the past decade. In this study, microstructure and mechanical behavior of uncoated and hydroxyapatite (HA)-coated polymeric meshes, fabrics, and mats were investigated. Commercially available monofilament PEEK meshes, and cellulose fabrics and mats were selected, then coated with a customized low temperature sol–gel method (≤ 150°C). Adhesive HA coating consisting of HA, β-TCP, and CaO with nanorod structure was derived. After HA coating, porosity of substrates (except filter-paper cellulose mats) decreased by up to 43%, indicating effective coating. Both uncoated and HA-coated substrates’ degradation rate in phosphate-buffered saline decreased after day 3. This is a result of ion precipitation or calcium compounds formation, indicating potential stability in biofluids for an extended period of time. Regarding tensile test results, highest tensile strength and elongation at break were obtained for PEEK meshes (approximately 80 MPa and 35%, respectively), as a result of the bulk material properties. HA coating did not significantly affect the tensile properties of the specimens, except for cellulose mats with an initial porosity of 77% (tensile modulus increased by 270% and strength by 210%). The increase in tensile properties could be attributed to increased rigidity, resulting from the adhesion between HA coating and cellulose fibers. Overall, HA-coated cellulose mats and PEEK meshes show promise as customizable, flexible scaffolds for implant applications and bone regeneration for future work.