Katarzyna Suchanek

Crystalline hydroxyapatite coatings synthesized under hydrothermal conditions on modified titanium substrates

Hydroxyapatite coatings were successfully produced on modified titanium substrates via hydrothermal synthesis in a Ca(EDTA)(2-) and (NH4)2HPO4 solution. The morphology of modified titanium substrates as well as hydroxyapatite coatings was studied using scanning electron microcopy and phase identification by X-ray diffraction, and Raman and FTIR spectroscopy. The results show that the nucleation and growth of hydroxyapatite needle-like crystals with hexagonal symmetry occurred only on titanium substrates both chemically and thermally treated. No hydroxyapatite phase was detected on only acid etched Ti metal. This finding demonstrates that only a particular titanium surface treatment can effectively induce the apatite nucleation under hydrothermal conditions.

Surface characterisation of Ti–15Mo alloy modified by a PEO process in various suspensions

This paper reports on the surface modification of a Ti-15Mo alloy by plasma electrolytic oxidation (PEO). This process was carried out in solutions of 0.1M Ca(H2PO2)2 with various concentrations of tricalcium phosphate (Ca3(PO4)2), wollastonite (CaSiO3), or silica (SiO2) using voltages of up to 350V. The surface microstructure (SEM, cross-section of coating), roughness and chemical composition (energy-dispersive X-ray spectroscopy, thin layer X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy) of the porous oxide layers were investigated. The concentration of powder added to the solution changed the chemical composition and morphology of PEO coatings on the Ti-15Mo alloy surface. Calcium and phosphorous compounds were detected in the coatings formed on the substrate by the PEO process at 300V.

Biological effect of hydrothermally synthesized silica nanoparticles within crystalline hydroxyapatite coatings for titanium implants

Development of functional coatings for artificial bone implants that strengthen the osseointegration and accelerate bone healing processes is urgently needed in the biomedical field. In this study we present biological effect of novel composite coatings with different concentration of silica nanoparticles within crystalline hydroxyapatite matrix (HAp-SiO2) synthesized on titanium under hydrothermal conditions. Samples were analyzed for their elemental composition, structure, bioactivity and in vitro cytotoxicity. The results indicate the formation and homogeneous distribution of silica nanoparticles on the surface of hexagonal hydroxyapatite (HAp) crystals. The coatings show improved bioactivity in comparison with pure HAp after 4 days of immersion in simulated body fluid (SBF). The responses of human osteoblast-like cells (MG-63) cultured onto the synthesized materials provide evidence that HAp-SiO2 composites exhibit good biocompatibility. We propose that this is because HAp-SiO2 composites favor biomineralization process with cell proliferation remaining unaffected, regardless of the amount of silica. Furthermore, SEM and fluorescence measurements demonstrate that HAp-SiO2 had positive effect on cell morphology, favoring cell adhesion.

From monetite plate to hydroxyapatite nanofibers by monoethanolamine assisted hydrothermal approach

Calcium phosphates offer outstanding biological adaptability. Thanks to their specific physico-chemical properties they are one of the most widely used materials in bone tissue engineering applications. The search for an innovative and economic strategy of synthesizing their different forms has been drawing considerable attention in the field. Herein, we report on a facile hydrothermal process in the presence of ethylenediamine tetraacetic acid and monoethanolamine to obtain various forms of calcium phosphates. The monoethanolamine served as an alkaline source and crystal growth modifier, while ethylenediamine tetraacetic acid was used to control the Ca2+ supersaturation level under high temperature and high pressure conditions. The obtained inorganic compounds were examined for their elemental composition, morphology, and structure using scanning electron microscopy, Raman spectroscopy, and powder x-ray diffraction. We were able to selectively synthesize monetite plate-like microcrystals as well as hydroxyapatite plates and nanofibers by simply varying the concentration of monoethanolamine.

Magnetic resonance imaging using optically polarized 3He

Magnetic resonance imaging (MM) using optically polarized 3He is a new and very promising diagnostic method for studying structure and function of lungs. A novel low field MRI system based on permanent magnet and a home-built 3He polarizing unit is presented. The system is designed to perform experiments on small animals. First 1H and 3He images of phantoms small biological objects and rat lungs in vivo are shown.