Aims: The aim of this research work was the realization of an inorganic bioactive scaffold for bone regeneration. This biomaterial should be macroporous, in order to allow the bone in-growth, and bioactive aiming to promote the bone regeneration and healing.

Methods: The macroporous biomaterial was prepared by consolidation of a suspension of starch and SiO2-CaO-Na2O-MgO glass powders. Starch powders were used as both pore former and consolidation agent. Starch-glass green bodies were prepared by uniaxial pressing and, after drying, they were heated to remove the organic phase and to sinter the inorganic one. The sintered scaffolds were characterized by X-Ray diffraction, scanning electron microscopy and mercury intrusion porosimetry. The scaffolds bioactivity was evaluated soaking the samples in a simulated body fluid for periods up to 4 weeks. On the most representative samples, in vitro tests of adhesion and proliferation were performed using human primary osteoblast-like cells.

Results: The obtained scaffolds showed an interconnected macroporosity of 50–100 B5m and a satisfactory degree of sintering. The sintering treatment induced the nucleation and growth of Na2Ca2(SiO2)3 crystals which is a phase that possess a very high bioactivity index. By soaking the scaffolds in SBF for period up to 1 month, an extensive precipitation of hydroxylapatite, with the typical globular morphology, occurred both inside and outside the pores. The adhesion and proliferation tests showed a remarkable spreading of the osteoblasts on the scaffold surface and thus a good biological response.

Conclusions: Scaffolds with interconnected porosity were successfully obtained. The pores are highly interconnected and homogenously distributed in the samples. The chosen thermal treatment and the use of starch powders led to a final macroporous glass-ceramic structure. The obtained scaffolds showed a very high in vitro bioactivity with precipitation of HAp. Moreover, preliminary biological tests, showed a satisfactory cellular interaction with the proposed biomaterials. For the above-mentioned reasons, the starch consolidation method, the optimized processing parameters and the tailored glass composition can be used to produce scaffolds suitable for bone substitutions and tissue engineering.

Aims: A prospective multicentric study was carried out in patients having metal-on-metal METASUL components to check if the concentration markers of chromosomal damage (Sister Chromatid Exchanges (SCEñs) and Micronuclei (Mni) and that of Co, Cr, Ni and Mb in the body ßuids are affected by the implant of METASUL components within 6 months. Methods: 30 patients were enrolled homogeneous as to the exposition to mutagenic agents. Observation times were pre-op., 7 days, 2 months, 6 months; blood and urine samples were taken at each observation time, and the markers of chromosomal damage (blood) and the ion concentration (blood and urine) were measured. Results: measurements showed a 2-fold increase of Co in blood, a 10-fold increase of Co in urine, a 1.5-fold increase of Cr in the blood and a 3-fold increase of Cr in the urine at a follow-up of 6 months from the operation; the Ni blood concentration was also increased at the 7 day check-up. The study cohort did not show any modiþcation in the frequency of markers of chromosomal damage at any of the observation times. The amount of the SCEñs and Mni recorded at all the observation times did non correlate with each other nor with any of the ion levels measured in the blood and in the urine. Conclusions: the implant of prostheses with METASUL components determines an increase in the concentrations of mainly Co and Cr in blood and urine, but that this increase has no genotoxic effects on the peripheral lymphocytes in the selected group at a follow-up of 6 months.