In-Depth Comparative Assessment of Different Metallic Biomaterials in Simulated Body Fluid.

Invitro experiments have been conducted on metallic biomaterials used for orthopedic implants in order to determine their behavior when immersed in simulated body fluid (SBF). Thus, 3Ti-based metallic biomaterial samples already available on the marked were purchased and immersed in simulated blood plasma, and kept at 37 °C for 4 months. In-depth characterization consisted of a wide series of structural characterizations of both the samples and SBF. Sample analysis consisted of the following: optical (OM) and scanning electron microscopy (SEM) in order to establish the surface and deep corrosion, mass gain/loss assessment for determining the metallic ions loss and/or protective layer formation, and X-ray diffraction in order to establish if and what kind of layers are formed. SBF analysis consisted of using inductively coupled plasma mass spectroscopy (ICP-MS) in order to establish if and/or how many metallic ions have dissociated from the metallic samples into the SBF, and measurements of pH and electrical conductivity. The key findings of the research are as follows: during the four months while kept in SBF, the samples show surface corrosion degradation and protective layer generation. Also, the amount of metallic ions dissociated into the SBF is making them suitable for use. Taking into account that it is highly improbable for such a large area of metal as the one considered within this work to be exposed to real body fluids and that all the samples have developed protective oxide films, the overall conclusion is that they are appropriate for implant use.

Synthesis and characterization of new composite materials based on poly(methacrylic acid) and hydroxyapatite with applications in dentistry.

The use of methacrylic acid (MAA) in medicine was poorly investigated in the past but can be of great importance because the incorporation of hydroxyapatite (HA) can lead to new composite materials with good properties due to the strong electrostatic interactions between carboxylate groups of polymer and Ca(2+) ions from HA. The scope of this study was to determine the potential of using composite materials based on poly(methacrylic acid) (PMAA) and hydroxyapatite in dentistry. Two routes of synthesis were taken into account: i) HA was synthesised in situ and ii) commercial HA was used. Fourier transform infrared spectroscopy and X-ray diffraction were used for compositional assessments. Scanning electron microscopy was performed to determine the morphology and differential thermal analysis (DTA) coupled with thermogravimetric analysis (TG) was used to study the thermal behaviour and to observe quantitative changes. In-vitro tests were also performed in order to evaluate the biocompatibility of both PMAA/HA composites by monitoring the development potential of human endothelial cells using MTT assay and fluorescent microscopy.