Biomedical subjects

C Vitale Brovarone

Publications and source records attributed to C Vitale Brovarone.

4 recordsLinked to original sources

PubMed2006

Macroporous bioactive glass-ceramic scaffolds for tissue engineering.

Highly bioactive scaffolds for tissue engineering were synthesized using a glass belonging to the SiO2-CaO-K2O (SCK) system. The glass SCK was prepared by a traditional melting-quenching route and its bioactivity was assessed by in vitro tests in a simulated body fluid (SBF). The glass was ground and sieved to obtain powders of specific size that were subsequently mixed with polyethylene particles of two different dimensions. The powders were then uniaxially pressed to obtain a crack free green compact that was thermally treated to remove the organic component and to sinter the inorganic phase. The obtained biomaterial was characterised by means of X-ray Diffraction, SEM equipped with EDS, mercury intrusion porosimetry, density measurements, image analysis, mechanical tests and in vitro evaluations. A glass-ceramic macroporous scaffold with a homogenously distributed and highly interconnected porosity was obtained. The amount and size of the introduced porosity could be tailored using various amounts of polyethylene powders of different size.

Biocompatible Materials↗

PubMed2005

Surface characterization of silver-doped bioactive glass.

A bioactive glass belonging to the system SiO(2)-CaO-Na(2)O was doped with silver ions by ion exchange in molten salts as well as in aqueous solution. The ion exchange in the solution was done to check if it is possible to prepare an antimicrobial material using a low silver content. The doped glass was characterized by means of X-ray diffraction, SEM observation, EDS analysis, bioactivity test (soaking in a simulated body fluid), leaching test (GFAAS analyses) and cytotoxicity test. It is demonstrated that these surface silver-doped glasses maintain, or even improve, the bioactivity of the starting glass. The measured quantity of released silver into simulated body fluid compares those reported in literature for the antibacterial activity and the non-cytotoxic effect of silver. Cytotoxicity tests were carried out to understand the effect of the doped surfaces on osteogenic cell adhesion and proliferation.

Anti-Bacterial Agents↗

PubMed2003

Fluoroapatite glass-ceramic coating on alumina: surface behavior with biological fluids.

The results of a surface analysis performed on a fluoroapatite-based glass ceramic (SAF) also coating a full-density alpha-alumina substrate (SAF-alumina coating) are presented. These two materials have also been evaluated after soaking in simulated body fluid to understand their ability to induce hydroxyapatite growth on them. Aiming to understand the fluoroapatite glass-ceramic interaction with some plasma proteins, in the second part of this study, fibronectin, albumin, immunoglobulin G, IgA, and complement factor C3c SAF binding have been evaluated; surface activity on complement activation has also been quantified. SAF-alumina coating provides good sites for the nucleation and growth of an apatite layer, equivalent to the mineral component of bone and binds preferentially plasma fibronectin, which is well known to enhance cell adhesion and spreading. Moreover, SAF-alumina coating reduces alumina complement activation directly or via reduced IgA binding. Alumina was shown to bind the same C3 fragments as Zymosan, used as complement activating control, and to induce increased levels of serum soluble iC3b and Bb. A mechanical resistant material with enhanced bioactivity, bone integration, and reduced inflammatory potential respect to alumina has been obtained.

Adsorption↗

PubMed2002

Fluoroapatite glass-ceramic coatings on alumina: structural, mechanical and biological characterisation.

The aim of this work was to realise bioactive coatings on full density alpha-alumina substrates. An SiO2-CaO-based glass (SC) and an SiO2-Al2O3-P2O5-K2O-CaO-F--based glass-ceramic (SAF) were used for this purpose. Specifically, SAF is a fluoroapatite containing glass-ceramic and previous studies have shown that it is a highly bioactive biomaterial. Furthermore, these fluoroapatite crystals possess a needle-shaped morphology which mimics that of hydroxylapatite found in human hard tissues, particularly in teeth. SAF is a very viscous glass-ceramic and for this reason an intermediate, less viscous, SC layer was interposed in direct contact with alumina aiming to obtain a good coating adhesion. Moreover, this intermediate layer strongly lowers the Al3+ diffusion and thus minimises both compositional changes in the SAF outer layer and the risk of detrimental modifications of the nature of the crystalline phases. A complete characterisation of the coated samples was performed by means of X-ray diffraction, optical and scanning microscopy. Coating adhesion on alumina was tested by comparative shear tests while biocompatibility was investigated on alumina. bulk SAF and on the realised coatings. For this purpose, cytotoxicity, adhesion and proliferation of human osteoblast-like cells were cultured onto the three materials. Results showed that the interposition of the SC layer was successful in allowing a good softening and spreading of the SAF outer layer and in avoiding the crystallisation of undesired crystalline phases maintaining the good bioactive properties of the bulk one. In vitro results on the coatings showed osteoblast-like cell behaviour similar to bulk fluoroapatite glass-ceramic and better respect to alumina substrates, being a promising index of bone material integration and of its in vivo possible applications.

Aluminum Oxide↗