Mechanical properties of polyvinylalcohol/hydroxyapatite cryogel as potential artificial cartilage

Abstract

The technological advances in material science are not enough to overcome the challenge of construct a material be able to replace the cartilage. The designed material has to meet the mechanical properties of cartilage and has to be capable to be integrated to the articulation. Articular cartilage damage is a persistent and increasing problem which affects millions of people worldwide. Poly vinyl alcohol (PVA) hydrogels are promising implants, due to their similar properties as soft tissue, however their low mechanical resistance and durability together with its lack to integrate with the surrounding tissue restrict their application in this area. The poor adhesion can be solved by the development a composite hydrogel with bioactive and biocompatible filler, as hydroxyapatite (HA). The aim of this work was to obtain and characterize (physical, chemical and mechanical) PVA/HA composite hydrogels for potential application as articular replacement. Hence composite hydrogels were prepared with the adding of different amount of HA in an aqueous solution of PVA and subsequent freezing-thawing cycles. It was observed that the adding of the HA modified the physical and chemical features of the hydrogel, promoted the material crosslinking and stability. Moreover, it was found that the mechanical properties (compression, tension and nanoindentation) of the hydrogels were improved by the addition of HA. All these result indicate that these materials could be used as a potential cartilage replacement. However, further in vitro and in vivo studies are mandatory for future possible clinical applications and are actually being carried out.