Mechanical properties of cellulose–apatite composite fibres for biomedical applications

Cellulose–apatite composite fibres with a diameter of 22 μm were prepared by coextrusion of a cellulose slurry loaded with 10, 30 and 50 vol.-% (with respect to dry cellulose, (C6H10O5)n with n=400) hydroxyapatite (HA, Ca10(PO4)6(OH)2) powder with an average particle size of 4˙1 μm. The cellulose solution was prepared according to the Lyocell technique. In the dry state, the tensile strength σ t and the ultimate strain ε u of cellulose fibres decreased with increasing HA filler loading. In the wet state, however, intermolecular incorporation of water in the cellulose matrix resulted in an increase in the ultimate strain of the composite fibre containing 10 vol.-%HA from 5˙6% (dry) to 9˙9% (wet). Textile structures fabricated of cellulose–apatite composite fibres could serve as scaffolds for the regeneration of osseous defects.