Composite device for attachment of polyvinyl alcohol-hydrogel to underlying bone

Polyvinyl alcohol-hydrogels (PVA-H) have been specifically proposed as promising prosthetic biomaterials because of their excellent mechanical properties and biocompatibility. However, it is very difficult to obtain stable long-term fixation of implanted PVA-H and this problem is the key point to be solved in the further development of PVA-H in biomedical applications more widely in various fields. Orthopedic implants using PVA-H have been developed and in the process this problem was solved using a composite device. This device consists of PVA-H and a titanium fiber mesh (TFM) as a porous tissue-ingrowth material. In the present study, the mechanical properties of this composite device produced using a new improved production method (injection molding) were investigated and animal experiments for in vivo evaluation were performed. In vitro tests showed that the shear strength at the interface of the PVA-H and TFM, and the mechanical properties of PVA-H itself were promising. Moreover, the histological appearance of the composite device implant in vivo showed abundant bone ingrowth into the deep pore spaces of TFM, which indicated that this device attached firmly to the adjacent bone. These results indicated this composite device prepared by this new method can supply firm attachment of PVA-H onto underlying bone, and that it will be available for various biomedical applications using PVA-H.