Composite hydrogels for intervertebral disc prostheses

Different PHEMA/PCL semi-IPNs hydrogels and their relative composite systems reinforced with PET fibres have been investigated for potential use as intervertebral disc prostheses. Compression properties and water absorption were evaluated. Uniaxial compression tests on the swollen samples showed an increase of the modulus and maximum stress with increasing content of PCL and PET fibres. In particular, the composite PHEMA/PCL hydrogels showed compression properties similar to those expressed by the canine intervertebral discs in different spinal locations. The equilibrium water content of modified semi-IPNs decreased as function of the PCL and PET fibres. These tests indicate that the use of composite hydrogels as disc prostheses is very promising because it is possible to combine transport and mechanical properties which are crucial for the performance of the intervertebral disc.