Biomedical subjects

C Vitale-Brovarone

Publications and source records attributed to C Vitale-Brovarone.

4 recordsLinked to original sources

PubMed2006

Development of glass-ceramic scaffolds for bone tissue engineering: characterisation, proliferation of human osteoblasts and nodule formation.

Glass-ceramic macroporous scaffolds for tissue engineering have been developed using a polyurethane sponge template and bioactive glass powders. The starting glass (CEL2) belongs to the system SiO(2)-P(2)O(5)-CaO-MgO-Na(2)O-K(2)O and has been synthesised by a conventional melting-quenching route. A slurry of CEL2 powder, polyvinyl alcohol and water has been prepared in order to coat, by impregnation, the polymeric template. An optimised thermal treatment was then use to remove the sponge and to sinter the glass powders, leading to a glass-ceramic replica of the template. Morphological observations, image analyses, mechanical tests and in vitro tests showed that the obtained devices are good candidates as scaffolds for bone-tissue engineering, in terms of pore-size distribution, pore interconnection, surface roughness, and both bioactivity and biocompatibility. In particular, a human osteoblast cell line (MG-63) seeded onto the scaffold after a standardised preconditioning route in simulated body fluid showed a high degree of cell proliferation and a good ability to produce calcium nodules. The obtained results were enhanced by the addition of bone morphogenetic proteins after cell seeding.

Biocompatible Materials↗

PubMed2005

SiO2-CaO-K2O coatings on alumina and Ti6Al4V substrates for biomedical applications.

Alumina and Ti6Al4V alloys are widely used for orthopedics and dental applications due to their good mechanical properties and biocompatibility. Unfortunately they can not provide a satisfactory osteointegration when implanted. In fact, both alumina and Ti6Al4V are not bioactive and thus they can only guarantee a morphological fixation with the surrounding tissues without a suitable chemical anchorage. Aiming to impart bioactive properties to these materials a coating can be proposed. At this purpose, a bioactive glass belonging to the SiO2-CaO-K2O system was selected and prepared. This glass, named SCK, possess a thermal expansion coefficient matching with the alumina (8.5x 10(- 6)/ degrees C) and Ti6Al4V (9 x 10(- 6)/ degrees C) ones and thus is a good candidate to produce coatings on both of them. Simple and low-cost enameling and glazing techniques were used to realize the coatings. Structural, morphological and compositional characterizations of the coatings were carried out by means of X-ray diffraction, optical and scanning microscopy and compositional analyses. The in vitro properties of the coatings were investigated by soaking them in a simulated body fluid (SBF) in order to study the precipitation, on their surfaces, of a biologically active layer of hydroxylapatite (HAp).

Alloys↗

PubMed2005

Microstructural and in vitro characterization of SiO2-Na2O-CaO-MgO glass-ceramic bioactive scaffolds for bone substitutes.

In the present research work, the preparation and characterization of bioactive glass-ceramic scaffolds for bone substitutes are described. The scaffolds were prepared by starch consolidation of bioactive glass powders belonging to the SiO2-Na2O-CaO-MgO system using three different organic starches (corn, potatoes and rice) as reported in a previous screening process. The scaffolds, characterized by scanning electron microscopy, showed a porous structure with highly interconnected pores. The pores sizes assessed by mercury intrusion porosimetry put in evidence the presence of pores of 50-100 microm. The structure of the scaffolds was investigated by X-ray diffraction and revealed the glass-ceramic nature of the obtained material. The mechanical properties of the scaffolds were evaluated by means of compressive tests on cubic samples and the obtained results demonstrated their good mechanical strength. The in vitro bioactivity of the scaffolds was tested by soaking them in a simulated body fluid (SBF) and by subsequently characterizing the soaked surfaces by SEM, EDS and X-ray diffraction. Good in vitro bioactivity was found for the starting glass and for the obtained scaffolds. Moreover, the scaffold bioresorption, tested by measuring the samples weight loss in SBF at different periods of time, showed a partial resorption of the scaffolds. Cell culture testing of the three different scaffolds indicated no differences in cell number and in alkaline phosphatase activity; the morphology of the osteoblasts showed good spreading, comparable to bulk material which was used as the control.

Body Fluids↗

PubMed2004

Macroporous glass-ceramic materials with bioactive properties.

In the present research work, glass powders and three different organic starches were used to realize macroporous glass-ceramic scaffolds for bone substitutions. For this purpose, bioactive glass powders belonging to the system SiO2-CaO-Na2O-MgO were mixed in a liquid medium with the desired amount of the selected organic phase. Afterwards, by progressively raising the temperature, the water uptake of starches occurred and led to the gelling of the whole system. The resultant gel underwent two thermal treatments in order to eliminate the organic phase and to allow the sintering of the glassy phase. In this way, macroporous glass-ceramic scaffolds were successfully prepared. The samples were characterized by means of optical and scanning electron microscopy with compositional analysis. The volume and mean size of the obtained porosity were investigated by means of mercury intrusion porosimetry, whereas its morphology was assessed by means of microscopic observations. The structure of the original and the resultant materials were investigated by X-ray diffraction. In order to study the reactivity of the scaffolds towards physiological media, the samples were soaked in a simulated body fluid for various times. On their soaked surfaces, scanning electron microscopy and compositional analysis were carried out in order to assess their bioactivity.

Body Fluids↗