Improved mechanical properties of brushite-forming calcium phosphate cements by polymer fiber reinforcementThursday (09.05.2019) 11:50 - 12:10 Part of:
Brushite-forming calcium phosphate cements have rather weak mechanical properties to be used for load bearing applications such as verteoplasty for the treatment of vertebral body fractures. The outstanding potential of brushite forming cements is the degradability of this material. Reinforcement strategies should therefore not alter this property. It has already been shown that reinforcement with resorbable PLGA polymeric fibers has led to an increase of work of fracture. However, interface shear strength between fiber and matrix is low, therefore fibers of more than 2 mm in length would be needed to make fully use of the fiber’s properties. Yet, the long fibers cannot be applied since they dramatically reduces the cement past injectability. To improve interface shear strength of 1 mm long fibers, the PLGA fibers were coated by layer by layer technique with gelatin, chitosan and hyaluronic acid polyelectrolyte layers. For cement reinforced with 5 and 10 wt % of coated fibers the fracture strength increased from 9 MPa to 12 MPa, whereas the shear strength increased by 100% for fibers coated with hyaluronic acid and chitosan multilayers. The work of fracture has increased by 100% at a strain of 1% when compared to non-reinforced cement.