RESUMO
In this study, we considered the biofilms as a surface, characterizing them using instruments for surface analyses, environmental microscopy, IR-spectroscopy (ATR-mode) and goniometry of the contact angle. The bacteria that formed the biofilms were grown on two different supports: beta-titanium alloy (beta-Ti) and polyethylene (PE). Environmental microscopy allowed the observation of biofilms in situ and in their hydrated state. On the metallic support, the biofilm quickly adhered and formed a dense structure with micro-colonies, but on the PE a thinner biofilm layer was observed covering a large surface area of the support. IR-spectroscopy is another effective method to detect the biofilm quickly and in situ, without pre-treating the sur-face. Nevertheless, problems with the overlapping of the characteristic bands on the spectra are frequent between the biofilm and PE. Finally, we compared the surface energy (SE) of the supports before and after biofilm formation. Our results indicate that the SE of the supports depends on the sterilization method, and that the SE of the biofilms varies depending on the support and the sterilization method. The biofilm on the beta-Ti had the highest SE, and as mentioned above, microscopic images showed a higher roughness on its surface.
RESUMO
Following an original synthesis route, we have prepared a single-component calcium phosphate apatite-like powder which settles and hardens when mixed with deionized water in an approximative 1.2 g:1 ml ratio. This paper describes the first physico-chemical studies and characterizations of the material. Observations of its in vitro behavior show a slight volume contraction and toxicity against fibroblasts bone marrow cells on disks of compacted powder. It is suggested that after an improvement of the powder characters such as grain size, and the choice of another hardening liquid, to name a few, this material should be a potential--or an ingredient of--bone cement.
