Biological influence of Ca/P ratio on calcium phosphate coatings by sol-gel processing.

The objective of this work has been to develop low temperature sol-gel glass coatings to modify the substrate surface and to evaluate their bioactivity and biocompatibility. Glasses, based on SiO2·CaO·P2O5, were synthesized by the sol-gel technique using tetraethyl orthosilicate, calcium nitrate tetrahydrate and triethyl phosphate as precursors of SiO2, CaO and P2O5, respectively. Those materials, still in the sol phase, have been used to coat substrates by means of the dip-coating technique. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) has been used for characterize coatings and a microstructural analysis has been obtained using scanning electron microscopy (SEM). The potential applications of the coatings in the biomedical field were evaluated by bioactivity and biocompatibility tests. The coated substrate was immersed in simulated body fluid (SBF) for 21days and the hydroxyapatite deposition on its surface was subsequently evaluated via SEM-EDXS analysis, as an index of bone-bonding capability. In order to study the cell behavior and response to our silica based materials, prepared via the sol-gel method, with various Ca/P ratio and coating substrate, we have used the human osteoblast-like U2OS cell line.

Weekly epirubicin in advanced breast cancer.

Twenty-nine advanced breast cancer patients, considered unable to tolerate conventional cytotoxic chemotherapy, were treated with a weekly schedule of epirubicin (15 mg/m2 i.v.). All patients were fully evaluable. A remission of 34.5% was observed (2 CR; 8 PR), with a median duration of response of 9 months (range, 3-24 months). Side effects were mild, and on the whole the toxicity was negligible. This regimen showed a favorable therapeutic ratio in our series and seems active and well tolerated even in elderly and/or poor performance status patients.