[Evaluation of the cytotoxicity of cigarette smoke condensate by using different solvents]. / Valutazione della citotossicità del condensato di fumo di sigaretta utilizzando diversi solventi.

The use of short term in vitro tests is an important step in the evaluation of the mechanism of action of cigarette smoke condensate (CSC). This study evaluated the effects of both CSC and solvents on Swiss 3T3 murine fibroblast cells. Results show that after 24 hours of treatment, CSC exerts a dose-dependent cytotoxic activity, both in methanol and dimethyl sulfoxide (DMSO), through mechanisms involving cell death and alterations in cell proliferation and metabolism. On the contrary, after 1 hour of treatment, a cytotoxic effect is seen only with CSC in DMSO. In cell cultures devoid of CSC, similar results have been obtained after 24 hours with both types of treatment.

Development of hybrid materials based on hydroxyethylmethacrylate as supports for improving cell adhesion and proliferation.

A novel hydrogel based on 2-hydroxyethylmethacrylate and fumed silica nanoparticles is presented. The filler was mixed at increasing amount (3-40% w/w) to the organic monomer, before accomplish thermal polymerization. The hybrid composite materials obtained were characterized as far as concern the physical-chemical stability and sorption behaviour in water and water solutions. The novel hybrid hydrogels were compared to poly(hydroxyethylmethacrylate) (pHEMA) on cytocompatibility and ability to elicit cell adhesion and proliferation. These in vitro assays showed that the first ones were supporting cell growth better then pHEMA, moreover experiments on murine fibroblasts showed improved adhesion and proliferation with the increase of the nanomeric filler content. For a more physiological response, the in vitro tests should match biomaterials with cell populations typical of the implant site. Therefore, in view of future applications of these composites as scaffolds for bone engineering, in a successive step of our research we selected primary cultures of human osteoblasts (OB) as the most appropriate models to study the in vitro performance of these materials. The preliminary results obtained confirmed the remarkable improvement of OB adhesion properties of the new hybrids with respect to pure pHEMA.