Abstract
Aims: A new class of soybean-based biomaterials has been presented (patent PCT/GB01/03464) which shows good mechanical properties and an intrinsic anti-inflammatory potential, probably related to the phyto-hormone Genistein. This plant isoflavone is also reported to inhibit osteoclastic activity. Aim of this study is to evaluate in-vivo the bone response to such soybean-based biomaterials.
Methods: De-fatted soybean curd was prepared into granules which were subsequently implanted in a cylindrical cavity drilled into the femural canal of New Zealand White rabbits. Retrieved femurs were embedded in poly-methyl-methacrylate and samples were analyzed by back-scattered electron microscopy (BSEM).
Results: Retrieved operated femurs showed a macroscopic appearance similar to the non-operated controls. BSEM showed that granules were still present at the site of implantation after 8 weeks, but a clear progressive degradation took place from the periphery to the centre of the femural canal already after 3 weeks. The degradation of the granule was accompanied by the production of new trabeculae apposed to the surface of the material.
Conclusions: It can be hypothesised that the released Genistein shifts the metabolic balance towards bone production by inhibiting the macrophagic and osteo-clastic activities and that the material degrading surface supports the apposition and mineralization of newly-formed bone.
The abstracts were prepared by Ms Grazia Gliozzi. Correspondence should be addressed to her at the Italian Orthopaedic Research Society, Laboratory for Pathophysiology, Instituti Ortopedici Rizzoli, University of Bologna, Bologna, Italy.
