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"The study is devoted to synthesis and preliminary structural and morphological characterization of modified 45S5 glasses, in (66-x)SiO2∙27CaO∙4P2O5∙3TiO2∙xAl2O3 system, with potential applications in dentistry. The composition of the sol-gel derived samples was verified with respect to their nominal composition. The effect of partial SiO2 replacement with Al2O3 on samples structure and morphology is investigated. It was established that the Ca/P ratio is diminished in Al2O3 containing samples and that an amorphous hydroxyapatite phase similar to hydroxyapatite reported for bone tissue is formed. Keywords: bioglasses; sol-gel-synthesis; XRD; SEM; EDX. "

The aim of this study was the synthesis and structural characterization of SiO2–Al2O3 microspheres with SiO2 core and (100 − x)Al2O3·xFe2O3 (x = 0, 5, and 10 mol%) shell. Smooth spherical silica particles of uniform size around 1 μm have been synthesized as core material based on the Stober method. In order to enhance the specific surface area, the silica particles were coated with a thin nanostructurated shell, about 15 nm, of aluminum and iron oxides (100 − x)Al2O3·xFe2O3 (x = 0, 5, and 10 mol%). The embedding of iron oxide in the covering shell was related to potential applications of these composite biomaterials for contrast enhancement in magnetic resonance imaging (MRI) and at the same time for local treatments of cancer by hyperthermia. The XRD results point out the amorphous structure of the obtained core–shell particles. The TEM images evidence continuous shell coating of silica spherical microparticles and the XPS analysis of the surfaces prove the occurrence of iron oxide on the outermost layer of the microspheres. Both FTIR and XPS results evidence the formation of Al–O–Si linkage proving that Al2O3 and SiO2 are chemically bonded in the investigated core–shell microspheres.

Glasses of xCaO∙(80-x)P2O5·20Na2O system (0 ≤ x ≤ 30% mol %) with constant Na2O content were studied in order to evidence both structural and dissolution properties determined by CaO addition. Transparent vitreous samples were obtained in the investigated composition range. Thermal analysis evidenced the increase of both crystallisation and melting temperatures with CaO content. The relative mass loss of samples in simulated body fluid progressively increased with the extent of P2O5 substitution by CaO. The dissolution properties could be explained in relation with the structural changes concerning the PO4 units connectivity as pointed out by DTA and FTIR analysis.

The co-crystals formation of etravirine with three carboxylic acids was investigated. New co-crystals of etravirine with adipic acid, benzoic acid, and 4-hydroxybenzoic acid have been synthesized by wet milling of ingredients for 120 min. The novelty of these solid forms was first evidenced by powder X-ray diffraction. Their different morphology was evidenced by SEM microscopy. Spectroscopic analyses (FT-IR, MAS-NMR, and XPS) highlighted the hydrogen bonds between etravirine and co-formers, as a result of the solid-state reaction of the ingredients by wet milling. Thermal analyses pointed out that the milling process caused in co-crystals a reduction in the fusion enthalpy and the melting temperature, compared to the values obtained for etravirine. These co-crystals are stable up to four months on storage under extreme conditions, excepting the co-crystal with benzoic acid which begins to transform into a polymorph of etravirine after 30 days. The UV absorption spectra of the samples tested in three simulated physiological media with pH values of 6, 6.3, and 7 have evidenced the conformation change of etravirine due to hydrogen bonds between etravirine and carboxylic acids.

Bioactive glasses doped with silver are aimed to minimize the risk of microbial contamination; therefore, the influence of silver on the bioactive properties is intensely investigated. However, information related to the role played by silver, when added to the bioactive glass composition, on biocompatibility properties is scarce. This aspect is essential as long as the silver content can influence blood protein adsorption onto the surface of the glass, thus affecting the material's biocompatibility. Therefore, from the perspective of the biocompatibility standpoint, the finding of an optimal silver content in a bioactive glass is an extremely important issue. In this study, silver-doped bioactive glasses were prepared by a melt-derived technique, which eliminates the pores' influence in the protein adsorption process. The obtained glasses were characterized by X-ray diffraction, UV-vis, X-ray photoelectron (XPS) and Fourier transform infrared (FT-IR) spectroscopy; afterwards, they were investigated in terms of protein adsorption. Both UV-vis and XPS spectroscopy revealed the presence of Ag+ ions in all silver containing samples. By increasing the silver content, metallic Ag0 appears, the highest amount being observed for the sample with 1 mol% AgO2. Electron paramagnetic resonance measurements evidenced that the amount of spin-labeled serum albumin attached to the surface increases with the silver content. The results obtained by analyzing the information derived from atomic force microscopy and FT-IR measurements indicate that the occurrence of metallic Ag0 in the samples' structure influences the secondary structure of the adsorbed protein. Based on the results derived from the protein response upon interaction with the investigated glass calcium-phosphate based system, the optimal silver oxide concentration was determined for which the secondary structure of the adsorbed protein is similar with that of the free one. This concentration was found to be 0.5 mol%.

Second-century CE (common era) household pottery sherds found in the city of Napoca (present day Cluj-Napoca, Romania) in Roman Dacia were investigated by polarized light optical microscopy, X-ray powder diffraction, Fourier-transform infrared spectroscopy and cold field emission scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy to obtain information on technology, raw materials and site of production. Compositionally, all samples are similar with comparable fine and semi-fine microstructures and oriented microtextures. Optically, there is a gradual transition from microcrystalline to an amorphous illitic-muscovitic matrix. The small aplastic inclusions are mostly quartz and feldspar. Fine-grained carbonate aggregates are distributed inhomogeneously in the ceramic body. Well-preserved Middle Miocene foraminifera tests are characteristic of the ceramics. The gradual thermal changes of the matrix and the newly formed phases upon firing, such as ‘ceramic melilite’, Fe-gehlenite, clinopyroxene, glass, hematite and some maghemite support inferences regarding the technological constraints in producing the pottery. The firing took place in a mostly oxidizing atmosphere and the temperature extended from at least 850°C to >900°C. The Middle Miocene marly clay from the area surrounding the site shows similar mineralogical and micropalaeontological contents to those of the ceramic specimens and is the best candidate for the raw material used for local production of the Roman pottery.

The present study reports the results obtained by X-ray photoelectron spectroscopy (XPS) for new solid forms of antineoplastic agent 5-fluorouracil with anthelmintic piperazine obtained by liquid assisted ball milling and slurry crystallization methods as co-crystal and salt, respectively. The interest for these new solid forms of 5-fluorouracil with another drug consists in obtaining new compounds with potential pharmaceutical and biomedical applications. The XPS results bring additional deciding information on the atomic environments in the newly obtained solid forms of 5-fluorouracil with piperazine beside the earlier reported X-ray diffraction and infrared spectroscopy data. The deconvolution of N 1s core level spectra allows to distinguish unequivocally the protonated (salt) from hydrogen-bonded (co-crystal) nitrogen species based on the N 1s binding energy associated with the protonation of nitrogen atoms. The N 1s component around 402 eV observed only for the solid form obtained following the slurry route proves in this case the formation of a salt on basis of positively charged nitrogen resulted by protonation of secondary amine groups. Moreover, for the solid form obtained following the ball milling route, one notices a large negative shift of N 1s binding energy that supports the development of a co-crystal.

Powders of the 30Y2O3·30P2O5·40SiO2 vitroceramic were irradiated with broad spectrum d+Be (Eneutron = 0–14.5 MeV) and quasi-monoenergetic d+D neutrons (Eneutron = 12.4 ± 0.22 MeV). The absorbed dose of d+Be neutrons was Dn = 2.52 ± 8% Gy with Dγ = 0.22 ± 14% Gy accompanied gamma absorbed dose. The absorbed dose of d+D neutrons was Dn = 1.43 ± 8% Gy with Dγ = 0.21 ± 14% Gy gamma absorbed dose. The thermoluminescence (TL) induced in the vitroceramics was studied. Both the gamma and neutron component contributed to the TL signals. The relative neutron sensitivities were [(TLn/TLγ)/(Dn/Dγ)]d+Be = 0.04 ± 60% and [(TLn/TLγ)/(Dn/Dγ)]d+D = 0.11 ± 43%.

A new glass system xSeO2(1-x)[40P2O5-30CaO-20MgO-10Na2O] with nominal concentration of SeO2 ranging between 0 and 20 mol% was obtained by melting method. The amount of selenium determined on samples surface is much lower than that expected according to the added SeO2 amount, and this is due first to selenium volatility during melting. The Fourier transform infrared and Raman results evidence the glass network depolymerisation induced by progressive addition of selenium. The depolymerisation effect occurs more pronounced on samples surface than in their inside, as indicated by X-ray photoelectron spectroscopy analysis with respect to the dependence of bridging and non-bridging oxygens on selenium content.

A new melt derived glass system consisting of Co2O3 added to 40P2O5·25B2O3·25CaO·10Na2O matrix was investigated in order to evaluate the influence of cobalt ions on the network structure. Multiple techniques, i.e. X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy, Raman spectroscopy and X-ray Photoelectron Spectroscopy (XPS) were used to characterize the local structure, the nature of the chemical bonding and the surface composition of these samples. The XRD measurements proved the vitreous character of samples with 0 and 3 mol% Co2O3. At higher cobalt oxide content (5, 7 and 10 mol%) the occurrence of a crystalline phase characteristic to Co2P4O12 has been observed. The complementary spectroscopic studies (FTIR and Raman) revealed that the incorporation of Co2O3 enhances the network connectivity and thereby the short range order in samples. Depending on their amount, the cobalt ions differently influence the borophosphate network via the tetraborate/triborate and metaphosphate/pyrophosphate ratios. For the sample containing 10 mol% Co2O3 the FTIR analysis indicates absorptions assigned to vibrations in CoO6 tetrahedra and suggests the presence of six-coordinated cobalt ions in Co3 + valence state. This study has proven that borophosphate based glasses are able to entrap cobalt ions, are sensitive from structural point of view to the amount of Co2O3 and possess interesting structural peculiarities.

Monodispersed silica-based microspheres have been prepared by hydrolysis and condensation of tetraethoxysilane (TEOS) in a water–ethanol mixed solution using dodecylamine (DDA) as hydrolysis catalyst and template. Core-shell samples were produced by electrostatic attraction and heterogeneous nucleation of alumina or mixed alumina and iron oxide (1:1) shells on mesoporous silica core microspheres. The iron oxide embedded in the shell structure may be considered both for contrast improvement in magnetic resonance imaging and for the local treatment of cancer by hyperthermia. SEM/TEM analysis proves the spherical shape of the silica particles, the shell development on their surface as well as the distribution of aluminum and iron in the whole shell. The outermost layer of the microspheres was primary investigated by XPS, while the structural characterization of the samples was achieved using XRD, FTIR, EPR and NMR techniques.

The aim of the present study was to asses the formation of solid forms between the 5-fluorouracil chemotherapy drug and the anthelmintic piperazine. Two new solid forms of antineoplastic agent 5-fluorouracil with anthelmintic piperazine were obtained by liquid assisted ball milling and slurry crystallization methods. The N H hydrogen bonding donors and C = O hydrogen bonding acceptors of 5-fluorouracil allow to form co-crystals with other drugs delivering improved properties for medical applications, as proved for other compounds of pharmaceutical interest. Both new solid forms were investigated using X-ray powder diffraction (XRD), differential thermal analysis (DTA) and Fourier transform infrared (FTIR) spectroscopy. The XRD results show that by both methods were successfully synthesized new solid forms of 5-fluorouracil with piperazine. According to FTIR results the form prepared by lichid assisted grinding process was obtained as co-crystal and the other one, prepared by slurry method, resulted as a salt.

Background and purpose: Dynamic Wave Arc (DWA) is a system-specific noncoplanar arc technique that combines synchronized gantry-ring rotation with D-MLC optimization. This paper presents the clinical workflow, quality assurance program, and reports the geometric and dosimetric results of the first patient cohort treated with DWA. Methods and materials: The RayStation TPS was clinically integrated on the Vero SBRT platform for DWA treatments. The first 15 patients treated with DWA represent a broad range of treatment sites: breast boost, prostate, lung SBRT and bone metastases, which allowed us to explore the potentials and assess the limitations of the current DWA site-specific template solution. For the DWA verification a variety of QA equipment was used, from 3D diode array to an anthropomorphic end-to-end phantom. The geometric accuracy of each arc was verified with an independent orthogonal fluoroscopy method. Results: The average beam-on delivery time was 3 min, ranging from 1.22 min to 8.82 min. All patient QAs passed our institutional clinical criteria of gamma index. For both EBT3 film and Delta4 measurements, DWA planned versus delivered dose distributions presented an average agreement aboire 97%. An overall mean gantry-ring geometric deviation of-0.03 0.46 and 0.18 0.26 was obtained, respectively. Conclusion: For the first time, DWA has been translated into the clinic and used to treat various treatment sides. DWA has been successfully added to the noncoplanar rotational IMRT techniques arsenal, allowing additional flexibility in dose shaping while preserving dosimetrically robust delivery. (C) 2017 Elsevier B.V. All rights reserved. Radiotherapy and Oncology 122 (2017) 347-351

The present archaeometric study focuses on a set of archaeological siliceous lithic tools that are assigned to the early Vinča culture period (Vinča A and Vinča B1). They were found in several pit-houses at Limba-Oarda de Jos (SW Transylvania, Romania), an open settlement that has been dated to 5,405-5,310 cal. BCE, a period in the Middle Neolithic. A total of 322 retouched tools and débitage pieces were typologically and macroscopically investigated. From these, 20 pieces were analyzed by polarized light optical microscopy (OM) and 10 pieces were analyzed by Fourier-transform infrared spectroscopy (FTIR) in order to identify compositional characteristics, define the petrographic type, and establish the spectral fingerprint of each material. Four petrographic types were discriminated: radiolarite, chert, fossiliferous chert, and siliceous limestone. Mineralogically, the tools primarily consist of a mass of microquartz and fibrous microquartz (called also ‘chalcedony’) associated with radiolarians remnants (in radiolarites); fossil shell fragments (in the fossiliferous chert); and limestone components, such as ooliths and pellets (in the siliceous limestone). All samples show distinct FTIR bands, most of which are assigned to microquartz, quartz, and fibrous microquartz. The deconvolution of the FTIR spectra in the 950-1300 cm-1 domain reveals the contribution of several other phases, such as calcite and clay minerals. The results support the assumption that the tools made of chert, fossiliferous chert, and siliceous limestone were produced at the site from nodules that probably originated from the Upper Jurassic chert-bearing limestone that crops out nearby in the Trascău Mts. The tools made of radiolarite were most likely brought to the site as finished products from the Trascău Mts.

Simultaneous radiotherapy and hyperthermia yield synergistic improvement of therapeutic efficacy in cancer therapy. The study is focussed on sol-gel derived particles of 60SiO2•20Al2O3•10Fe2O3•10Dy2O3 (mol%) system functionalized with type I collagen. The addition to aluminosilicate matrix of Fe2O3•was thought for hyperthermia and of Dy2O3 for internal radiation therapy after neutron activation of dysprosium to 165Dy radioisotope. The collagen functionalization of these particles aimed to make them well accepted in the body and to contribute to destruction of reactive oxygen species, what has to be taken into account when nanoparticles are used for cancer therapy. The XRD, FTIR and XPS investigations were carried out on Fe-Dy-aluminosilicate particles of average size around tens of nanometers, before and after their incubation in collagen solution in order to prove the protein functionalization particles and to assess the changes in secondary structure of protein following this process. The results show the anchoring of the protein on particles surface in a few nanometers thin layer as well as some relative changes of protein secondary structure. After interface processes with particles surface, the secondary structure of amide I in collagen consists overwhelmingly of α-helices and only about 12 % of β-turns structure.

Chromium doped lanthanum oxide synthesized by glycerol-assisted sol-gel route was heat treated at different temperatures up to 860 °C in order to investigate the effect of treatment temperature on the atomic environment in these samples. The addition of Cr2O3 to La2O3 catalyst support and catalytic promoter was considered because chromium is an interesting catalyst dopant. As the temperature rises from 100 to 860 °C, nanostructured La(OH)CO3, La2O2CO3 and La(OH)3 phases are developed in the treated samples. The crystallites size increases with treatment temperature from about 10 nm up to 30 nm, and at the same time a higher surface basicity is obtained, that would imply an enhanced catalytic activity or an improved behavior as catalyst substrate. The La2O2CO3 stable phase against moisture was obtained by relative low temperature synthesis. The tendency to atmospheric CO2 adsorption was evidenced for La(OH)3 phase developed in the samples treated at 650 and 860 °C. The X-ray diffraction (XRD), Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses were used to evidence structural changes with influence on sample properties.

The xY2O3∙(60 − x)P2O5·40SiO2 vitroceramic compounds exhibited excellent TL output following beta irradiation, especially when doped with high Y2O3 concentrations, as showed in a recent work conducted by Biro et al., 2015. In the first section of this paper, the previous recorded TL glow peaks were further analyzed and their corresponding kinetic parameters such as an order of kinetics (b), trap depth (E) and frequency factor (s) were determined using the Chen’s peak shape method. In the second section, the thermoluminescence characteristics of SiO2-P2O5 doped with different Y2O3 concentrations were simulated using the TTOR (Two traps & one recombination center) model. All calculated TL glow curves were in good agreement with the experimental results.

This study reports about the influence of titania on the structure and bioactivity of 60SiO2 ⋅ (32 − x)CaO · 8P2O5 · xTiO2 glasses with 0 ≤ x ≤ 12 mol%. In order to analyse the evolution of the apatite structure self-assembled on the glass surface after immersion in simulated body fluid, a complementary approach of different techniques was applied such as X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy and Raman spectroscopy. It was evidenced that the crystalline hydroxyapatite amount and the size of the nanostructured apatite phase, i.e. crystalline and amorphous one, decrease with the rise of TiO2 content. FT-IR spectra recorded in reflection mode showed the increase of the apatite-like structure amount as the titania content became higher. On the other hand, the behaviour of the full width at half maximum of the most intense Raman signal originating from the apatite-like structure confirms the size decrease of the nanostructured apatite phase with the progressive addition of TiO2 and shows the existence of a less ordered apatite-like structure. The herein presented investigation demonstrates that the FWHM of the Raman signal combined with the FT-IR data recorded in reflection mode can be used as key spectral indicators for elucidating the evolution of apatite-like structures developed on the bioactive material surface. Copyright © 2016 John Wiley & Sons, Ltd.

New glasses following the P 2 O 5 ‐CaO‐B 2 O 3 ‐K 2 O‐MoO 3 composition were prepared using the classical melt quenching method in order to investigate and correlate their structural peculiarities with the composition and, moreover, with the bioactivity and biocompatibility behavior. The structure and surface morphology of samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Two complementary techniques were used to determine the elemental composition inside samples and on the outermost layer of their surface, namely energy dispersive X-ray (EDX) and X-ray photoelectron spectroscopy (XPS), respectively. For assessing in vitro the bioactivity of the synthesized glasses, the ability to form hydroxyapatite crystallites on their surface upon immersion in simulated body fluid (SBF) was checked using SEM and EDX analysis. The in vitro cytotoxic effect of samples was evaluated using a mitochondrial activity assay. The results reveal that the increase of MoO 3 content in the P 2 O 5 ‐CaO‐B 2 O‐K 2 O composition generates a continuously disordering of the local structure and the increase of Mo 6 + /Mo 5 + ratio values on samples surface. No bioactivity was observed for this glass system after 15 days of immersion in SBF. The in vitro toxicity studies show that samples containing MoO 3 up to 7mol% have a good biocompatibility with healthy human immortalized keratinocyte (HaCaT) cell line.

Glasses of (50-x)P2O5⋅20B2O3⋅20CaO⋅10K2O⋅xNb2O5 system, with 0 ≤ x ≤ 20 mol %, were obtained using the conventional melt quenching method. The correlation between the composition and the structural features was achieved using complementary techniques: X-ray diffraction, differential thermal analysis, infrared and Raman spectroscopy, electron paramagnetic resonance and X-ray photoelectron spectroscopy. The analysis of the experimental data indicates that the oxidation state of niobium ions (Nb3+, Nb4+ or Nb5+) is strongly influenced by Nb2O5/P2O5 ratio which has an important role on the local structure and properties of glasses. In the compositional range of 5-10 mol% Nb2O5, the Nb4+ ions are prevalent and they are disposed in sites of octahedral symmetry, acting as a glass modifier. A diminished number of Nb4+ ions occurs at high Nb2O5 concentrations (15 and 20 mol%) leading to Nb4+/(Nb5++Nb3+) ˂ 1 ratios, and in this case the Nb5+ ions play a glass former role developing a 3D chain-type lattice by interconnection of differently distorted NbO6 octahedra. The occurrence of highly distorted NbO6 units could impart ferroelectric properties of interest for optoelectronic applications.

Bioactive glasses of the CaO–SiO 2 –P 2 O 5 system were synthesized through a sol–gel template method using polyethylene-glycol (PEG) with different molar weights. The samples were investigated by differential thermal analysis, X-ray diffraction and Fourier transform infrared spectroscopy. Electron paramagnetic resonance spectroscopy was employed to evidence possible structural defects and to reveal the response of the investigated glasses to gamma irradiation, and related effects on protein adsorption and samples bioactivity. PEG addition during samples synthesis induces structural changes within the glass matrix, which are dependent on PEG molar weights. At the same time, the use of PEG favors the occurrence of network defects. For the samples prepared with PEG of increased molar weight a lower apatite-forming ability was evidenced by the test carried out in simulated body fluid. It was also demonstrated that the network defects of samples affect the secondary structure of the protein adsorbed on the glass surfaces.

Doxorubicin-loaded magnetic nanocapsules, based on N-palmitoyl chitosan and magnetite, have been prepared using a double emulsion method. The morphology and size of the nanocapsules have been investigated by transmission and scanning electron microscopy. Magnetic nanocapsules were nearly spherical in shape, with a mean diameter in the nanometer range, and positive zeta potential. Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD) and Energy Dispersive X-ray analysis (EDX) confirmed the structure of composite magnetic nanocapsules. Magnetic nanocapsules exhibited suitable magnetic saturation, superparamagnetic behavior and good ability to incorporate a chemotherapeutic agent, properties which can be exploited in many different areas of biomedicine.

A composite coating consisting from a chitosan (Chit) thin film containing a new bioactive glass SiO2-CaO-P2O5 (BG) was investigated by cyclic voltammetry. The bioactive glass–biopolymer coating has certain porosity and is a good insulator comparing with the biopolymer film. The in vitro short-time stability of Chit and BG-Chit coatings on glassy carbon (GC) electrode is studied by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), during about 1 day of contact with a protein-free and acellular simulated body fluid (SBF) having an ion concentration nearly equal to that of human blood plasma. The EIS data indicated that after 5 hours of immersion in SBF the Chit dissolution and the adsorption of SBF ions on BG matrix were initiated causing the formation of a new outer biomimetic and biologically active hydroxyapatite protective layer. The CV and EIS measurements results recommend the use of composite BG–Chit coatings for in vivo devices (implants, prostheses and tissue engineering scaffolds).

Thermoluminescence properties of xY2O3·(60-x)P2O5·40SiO2 vitroceramic compounds doped with xY2O3 at various concentrations (0≤x≤30mol%) were studied. Compounds with reduced Y2O3 concentration showed unsatisfactory dosimetric properties, while the vitroceramics composed of 20Y2O3·40P2O5·40SiO2 and 30Y2O3·30P2O5·40SiO2 exhibited bright signals, linear dose response and minimum detectable doses of 16mGy and 4mGy, respectively. Moreover, 30mol% Y2O3 doped vitroceramic exhibited good repeatability, acceptable batch homogeneity and poor fading signal, features that are recommending this material for dosimetry purposes.

The sol–gel derived 50SiO 2 ⋅30CaO⋅10Fe 2 O 3 ⋅10Dy 2 O 3 system was subjected to heat treatments at 500, 800 and 1200 °C in order to obtain crystalline phases of interest for biomedical applications. The structural changes were investigated by Fourier transform infrared spectroscopy (FTIR) and electron paramagnetic resonance (EPR). Both FTIR and EPR results support the development of wollastonite, hematite and magnetite crystalline phases desirable for samples bioactivity and heating possibility for hyperthermia treatment. Dysprosium addition was considered for subsequent radioactivation of the samples that could extend their application to thermoradiotherapy.

The study is focused on Na 2 O and/or K 2 O influence on a new sol–gel derived SeO 2 –B 2 O 3 –SiO 2 –P 2 O 5 –CaO bioactive system. The structural changes induced by Na 2 O and/or K 2 O addition were correlated with the samples behavior in simulated biological media. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy were used to characterize the structure and the type of the chemical bonds. The morphology of the samples was characterized through scanning electron microscopy (SEM). XRD results pointed out a prevalent vitreous structure with an incipient hydroxyapatite (HA) crystalline phase. FTIR results revealed a complex network consisting of silicate, phosphate and borate units, as well as the development of both A- and B-type of carbonate-substituted HA. The bioactivity of the samples was tested in vitro following the evolution of the apatite layers self-assembled on the samples surface in simulated body fluid. Their biocompatibility was investigated after samples surface functionalization with protein. The results indicate that sodium and potassium addition improves the biocompatibility by enhancement of protein adherence on samples surface and without to prevent the samples bioactivity.

The investigated polymethylmethacrylate intraocular lens explanted an year after implantation presented a fine granularity consisting of ring-like grains of about 15 μm in diameter. In order to evidence the changes occurred on intraocular lens relative to morphology, elemental composition and atomic environments, microscopic and spectroscopic analyses were carried out using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), energy-dispersive X-ray (EDS), and X-ray photoelectron (XPS) spectroscopies. The results revealed that the grains contain hydroxyapatite mineral phase. A protein layer covers the lens both in opacified and transparent zones. The amide II band is like in basal epithelial cells. The shape and size of the grains, and the XPS depth profiling results indicate the possibility of a cell-mediated process involving lens epithelial cells which fagocitated apoptotic epithelial cells, and in which the debris derived from cell necrosis were calcified. To the best of our knowledge, this is the first investigation on explanted intraocular lenses using XPS depth profiling in order to examine the inside of the opacifying deposits.

A silver containing series of glasses starting from Ag-free 1.5B2O3 · SiO · CaO parent glass and ending with 3 mol% Ag2O was synthesized by the conventional melt quenching method and analyzed in order to correlate the composition and the structural peculiarities with the antibacterial effects. The structure and surface morphology of samples were characterized by X-ray diffraction (XRD), infrared (FTIR) and Raman spectroscopy, Scanning Electron Microscopy (SEM). X-ray photoelectron spectroscopy (XPS) was used to determine the nature of chemical bonding and the surface composition of the samples. The results indicate that all samples are vitreous and their local structure — mainly built by tetrahedral (BO4‐), triangular (BO3 and BO2O−) borate species (O representing an oxygen atom bridging two boron atoms) and silicate Q1, Q2, Q3 units — is reactive to the silver oxide addition. Based on XPS data, both Ag+ and Ag0 ions are present on the surface of detected silver nanoparticles. Ag nanoparticles (AgNPs) embbeded in glasses were evaluated for their antimicrobial activity against the gram-positive and gram-negative bacteria, i.e. Staphylococcus aureus and Escherichia coli bacteria. The antibacterial effect of investigated samples increases simultaneously with the Ag2O content and AgNP dimension. The proposed mechanism is discussed in relation with the local structure, Ag+/Ag0 ratio and AgNP dimensions.

Three silicate systems, i.e. pure SiO 2 , SiO 2 –CaO and SiO 2 –CaO–MgO, were prepared via sol–gel method in two different ways: ( i ) following the acid catalysed route (noted A), and ( ii ) the quick alkali mediated route (noted Q). The thermal behaviour was investigated for the as-prepared matrices and, according to differential thermal analysis (DTA) and thermogravimetric (TGA) analyses, the calcination temperature was establish at 600 °C in order to remove the synthesis residues and to stabilise the structure. Structural, textural and morphological investigations on the heat treated samples were performed before and after immersion in simulated body fluid (SBF) by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N 2 -adsorption and scanning electron microscopy (SEM). After 600 °C thermal treatment the samples remain mainly amorphous, only the CaO containing samples prepared by A route evidence an incipient Ca 2 SiO 4 crystalline phase. The N 2 -adsorption results showed that the specific surface area and the pore volume of the samples synthesised by Q route have higher values comparing with their counterparts prepared following the A route. Bioactivity tests carried out in SBF proved that the magnesium addition to the matrix obtained by Q route favours the hydroxyapatite (HA) self-assembly on the glass surface, and inhibits HA formation when it is added to the matrix obtained by A route. These results are supported by both FTIR and SEM analyses.

Zinc containing bioactive glasses were prepared by means of sol–gel procedure, in the presence of polyethylene glycol (PEG) considered as surfactant agent. Fourier transform infrared spectroscopy (FTIR), UV–Vis absorption spectroscopy and electron paramagnetic resonance spectroscopy (EPR) were employed to reveal the bioactive glass response to gamma irradiation in terms of defects generation. The results proved that gamma irradiation induces structural changes within the glass matrix, which are strongly dependent on the sample composition. ZnO addition to the glasses network was found to confer structural stability against gamma irradiation, while the use of PEG during the samples preparation favoured the generation of network defects especially in ZnO containing samples.

Well-defined calcium molybdate (CaMoO4) and hydroxyapatite (HAP) nanocrystals were developed by thermal treatment on the surface of a SiO2–CaO–P2O5–MoO3 amorphous precursor synthesised at room-temperature by sol–gel route. The structural and morphological characterisaions were performed by several techniques: energy dispersive X-ray spectroscopy, thermal analyses (DTA/TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy, electron paramagnetic resonance. Complementary, Fourier transform infrared and Raman spectroscopies provided a clear picture regarding the short range order structure, emphasising beside the CaMoO4 phase development, the presence of HAP nanocrystals. The vibrational spectroscopic techniques proved to be valuable tools for evidencing very small HAP nanocrystallites that cannot be clearly observed by XRD and TEM analyses.

Multicomponent x B 2 O 3 [100− x ](61SiO 2 ·9 P 2 O 5 ·30CaO] system with 0≤ x ≤30 mol% was prepared by sol–gel method. The morphology of the 600 °C heat treated samples was characterised through Scanning Electron Microscopy (SEM). X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy and X-ray Photoelectron Spectroscopy (XPS) were used to characterise the local structure, the nature of the chemical bonding and the surface composition of these samples. Up to 10 mol% B 2 O 3 the samples have a glass-ceramic character, a crystalline phase characteristic to hydroxyapatite being detected through XRD measurements. With further increasing x the samples present a vitreous character. FTIR spectroscopy revealed a complex silicate and phosphate network consisting mainly of meta- and pyro-type units. The development of hydroxyapatite, A and B-type of carbonate-substituted hydroxyapatite was followed based on FTIR and XPS spectra analysis. The bioactivity of the samples has been analysed in vitro in simulated body fluid (SBF). The evolution of apatite layers self-assembled on the samples surface after immersion in SBF was analysed and discussed as a function of both boron content and immersion time. The results indicate that after five days of immersion, the microstructure of the sample with 10 mol% B 2 O 3 is quite close to that of dry human trabecular bone.

article The response of carbonate-rich illitic clay heated up to 1200 °C was investigated by means of electron paramag- neticresonance(EPR)inordertodefine the factors influencingtheshapeoftheresonancesignalsandtoestablish whether this method can be used for evaluation of firing temperature for clay-based ceramic objects. The results showthatthedominatinghyperfinesextet,atg ≅2,duetoMn 2+ ,isreplacedover700 °Cbyalargesignal,mainly due to Fe 3+ .O xidation of Mn 2+ (EPR active) to Mn 3+ (EPR silent) or Mn 4+ ,a nd Fe 2+ (EPR silent) to Fe 3+ (EPR active)respectively,combinedwithchangesintheirenvironmentproducetheresonancesignals.Thedestruction ofthecarrierssuchasFe-oxihydroxides,clinochlore,calcite,dolomite,alteredbiotite,illite andmuscovite,aswell astheformationofnewmineralsandglass arethemainmineralogical processesinfluencingthe widthof the res- onance signals. The results of this study can be used in conjunction with mineralogical and microstructural data for the investigation of technological conditions such as firing temperature and atmosphere related to archaeo

We synthesized a new boro-phosphate glass system with different %mol SeO2 content by conventional melt quenching technique. All samples were obtained in a glassy state with the vitreous structure confirmed by X-ray diffraction analysis. Scanning electron microscopy (SEM) revealed some non-homogeneous domains on the glasses surface, and their tendency to link each other once the selenium oxide content increases. Energy-dispersive X-ray analysis (EDAX) indicated similar elemental composition in different regions of each sample. X-ray photoelectron spectroscopy (XPS) was used to determine the nature of chemical bonding and the elemental composition at the sample surfaces, and Fourier transform infrared (FT-IR) spectroscopy was used to determine the structural groups in the obtained glass structure. Based on FT-IR results, the glass structure at short range order consists mainly of small phosphate units such as pyrophosphate (i.e. P2O74 − dimmers or terminating groups at the end of phosphate chains) and some metaphosphate (i.e. PO3− middle groups in the phosphate chains) units. The boron atoms are mainly placed in three-coordinated sites in BO3 or BO2O− units. A small contribution of BO4− units was also detected from the FT-IR spectra of glasses. For SeO2 content higher than 5 mol%, the modifier role of selenium ions is strongly reflected on the local structure dominated in this case by pyrophosphate units.

The formation of a calcium phosphate layer on the surface of the SiO2–CaO–P2O5 glasses after immersion in simulated body fluid (SBF) generally demonstrates the bioactivity of these materials. Grafting of the surface by chemical bonding can minimize the structural changes in protein adsorbed on the surface. Therefore, in this study our interest was to evaluate the bioactivity and blood biocompatibility of the SiO2–CaO–P2O5 glasses after their surface modification by functionalization with aminopropyl-triethoxysilane and/or by fibrinogen. It is shown that the fibrinogen adsorbed on the glass surfaces induces a growing of the apatite-like layer. It is also evidenced that the protein content from SBF influences the growth of the apatite-like layer. Furthermore, the good blood compatibility of the materials after fibrinogen and bovine serum albumin adsorption is proved from the assessment of the β-sheet–β-turn ratio. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 261–272, 2015.

Zinc–silica microparticles obtained by sol–gel method solely or by combining sol–gel chemistry with freeze-drying and spray-drying procedures were explored as potential insulin drug delivery carriers for their improved loading efficiency. Zinc containing silica hosts of different specific surface area and mean pore volume loaded with insulin under similar conditions were investigated by X-ray photoelectron spectroscopy (XPS) and confocal micro-Raman spectroscopy in order to assess the insulin adherence to these matrices and the biologically active state of the insulin after embedding.

This study presents some aspects regarding the evaluation of bone-implant interactions using two animal models (rabbit and rat). The proposed implants are new alumina/zirconia bioceramics designed for hard tissue replacement (oral implantology or arthroplasty). The animal selection was made based on the number and size or design of implants to be tested as these factors influence directly the species of animal chosen for this study. The correct placement and stability of the implants were evaluated by radiographic images. SEM micrographs were recorded on the bone/implant area along with the elemental composition of the sheared implant surfaces at different time intervals after the surgery. Calcium/phosphate ratio was considered as an indicative of the surface implant coverage for a successful osseointegration. Histological examination of the bone and bone marrow in direct contact with the implants was performed to detect any immunological or inflammatory responses. Each of the animal species (rat or rabbit) demonstrated unique advantages and disadvantages as a model for demonstrating the response of bone tissue to an implant material. The size and design of the implants also influenced the bone turnover as demonstrated histologically.

The aim of the present study was to produce and characterize three-dimensional (3D) interconnected macroporous glass-ceramic scaffolds with different amounts of zinc for tissue engineering applications. The scaffolds were obtained using sol–gel method without and with addition of polyethylene-glycol (PEG) combined with sacrificial template method. The structural and morphological properties of these samples were investigated using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, as well as scanning electron microscopy (SEM). PEG addition during scaffold synthesis produced changes on their structural properties that after heat treatment led to an increased crystalline phase content as compared to the sample prepared without PEG addition. At the same time, the scaffolds prepared with PEG showed higher pore interconnectivity and greater apatite-forming ability, as evidenced by the bioactivity test in simulated body fluid.

The structure and conformational dynamics of insulin entrapped into a silica matrix was monitored during the sol to maturated-gel transition by electron paramagnetic resonance (EPR) spectroscopy. Insulin was successfully spin-labeled with iodoacetamide and the bifunctional nitroxide reagent HO-1944. Room temperature continuous wave (cw) EPR spectra of insulin were recorded to assess the mobility of the attached spin labels. Insulin conformation and its distribution within the silica matrix were studied using double electron-electron resonance (DEER) and low-temperature cw-EPR. A porous oxide matrix seems to form around insulin molecules with pore diameters in the order of a few nanometers. Secondary structure of the encapsulated insulin investigated by Fourier transform infrared spectroscopy proved a high structural integrity of insulin even in the dried silica matrix. The results show that silica encapsulation can be used as a powerful tool to effectively isolate and functionally preserve biomolecules during preparation, storage, and release.

The aim of this study was to prepare and to characterize the structure of Al2O3–3YSZ composites with 5% TiO2 addition as well as the surface modification upon treatments with SnF2 and NaBF4, respectively. SEM micrographs showed the controlled densification of the composites as an effect of 3YSZ and TiO2 addition to alumina matrix. By FTIR and XRD, the characteristics of Al-O and Zr-O vibrations, respectively, the diffractions lines related to α-corundum and zirconia in tetragonal phase were discussed. Qualitative and quantitative results obtained by XPS and ATR FTIR demonstrated that the proposed materials are more sensitive to SnF2 than to NaBF4 treatment.

Bioactive glass with the composition 0.55SiO 2 ·0.41CaO·0.04P 2 O 5 was prepared following the sol–gel route as controlled delivery systems for tetracycline (TC). The maturation and drying of the gel under different conditions led to different behavior regarding the loading and release of TC from these matrices. The pore size modifications upon TC loading evidenced by BET method show different ability of the glass matrices with respect to TC incorporation, also supported by experimental EPR and fluorescence spectroscopy. EPR spectra of both TC solution and immobilized TC on the porous structure of glass specimens demonstrated changes in tetracycline structure during loading and upon adsorption. The TC release profile monitored by differential pulse voltammetry shows a maximum concentration after 2 h and a continuously slow release during the next 24 h. The obtained results demonstrate that the pores size modification related to different maturation and drying procedures seems to be a determinative factor in tetracycline release process.

Inorganic–organic hybrid materials like clay polymer nanocomposites (CPN) are a topic of increasing interest due to their implications in a broad range of applications including tissue engineering scaffolds and drug delivery systems. Our study is focused on CPN developed from polyvinyl alcohol and medical kaolinitic clay prepared by solution intercalation and mechanical mixing methods and characterised by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) techniques. Both components and nanocomposite materials were tested in simulated body fluid enriched with serum albumin for the assessment of the first biological response at the interface with entities of the living tissues. The protein attachment on the material surface was primarily revealed by N 1s photoelectron peak related to the protein amino groups. For both CPN the FTIR spectra evidenced characteristic absorption bands of amides I and II of the protein.

The proteins adsorption on biomaterials surface leads to changes in their structural conformation that may further influence the adhesion, migration and growth of cells. The aim of this study was to examine the attachment of collagen (calf skin type I) on bioactive glass powders and the conformational changes of the protein. Scanning electron microscopy analysis and X-ray photoelectron spectroscopy measurements indicate that the collagen cover the glass surface in a nanometric thin layer. The infrared amide I absorption signal shows pronounced changes in the secondary structure of the adsorbed collagen.

Two composites consisting of non-woven poly-96L/4D-lactide copolymer meshes and a bioactive glass containing silver and silver free were obtained in polyvinyl-alcohol solutions by slurry dipping method under slow mechanical stirring. The development of hydroxyapatite type nanocrystals on samples surface in simulated body fluid proved for both composites the tendency for high level of bioactivity. Their antibacterial effect was evaluated against Gram-negative Escherichia coli and Gram-positive Staphylococcus epidermidis. Both composites showed inhibitory effect on bacterial growth, but only the composite with silver containing bioactive glass proved to have bactericidal effect. The AgCl nanocrystals and Ag3PO4 particles self-assembled on the surface of this composite proved the release of silver ions into simulated body fluid.

The aim of our study is to compare the structural and biological tolerance of novel Al2O3/3Y-TZP composites with ceria respectively titania addition (5 wt%). Scanning electron microscopy, X-ray diffraction, infrared spectroscopy and XPS results are reported for structural characteristics and surface modifications upon different fluoride treatments. The biocompatibility of the samples was evaluated using an animal model (rabbit). The explants were analyzed at a specific period (6 weeks).The sections of implanted bone area were subjected to histological evaluation. Upon correlating the structural properties and in vivo evaluation, we concluded that the addition of both TiO2and CeO2to Al2O3/3Y-TZP implies similar properties and satisfactory biological tolerance. With respect to the surface treatment, qualitative and quantitative results show that the alumina/zirconia with titania addition are more sensitive to fluoride treatment.

Ternary zinc–calcium-phosphate glasses prepared by classical melting method were characterized through X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) along with energy dispersive X-ray analysis (EDAX), Fourier Transform InfraRed (FTIR) and Raman spectroscopy. The study of these glasses was done in order to supply information regarding their structural particularities since the zinc role in biological environment, especially in the bone, is still under debate. XRD analysis confirmed the vitreous character of the as-prepared samples, while SEM and EDAX measurements indicated the presence of some non-homogeneous domains on their surfaces with approximately similar elemental composition. According to FTIR and Raman spectroscopy, the local structure of glasses up to 10 mol% ZnO is mainly built by Q2 tetrahedrons connected by P–O–P linkages. For 50 mol% ZnO, the modifier role of zinc ions is strongly reflected on the local structure dominated in this case by Q1 pyrophosphate units. The surface reactivity of the samples has been analyzed in vitro by immersion in simulated body fluid (SBF) at 37 °C. XRD, SEM–EDAX, FTIR and Raman methods were employed to characterize the structural changes that occurred on the surface of ZnO–CaO–P2O5 samples reacting with SBF. The X-ray diffraction patterns demonstrated the formation of a hydroxyapatite layer on the samples surface while the other used methods didn't reveal concisely that phenomenon. Based on X-ray measurements, the influence of zinc concentration on the hydroxyapatite layer development was followed.

The attachment of fibrinogen on the bioactive glass surface is investigated by means of Fourier transform infrared spectroscopy (FT-IR). The β-sheet/β-turn ratio estimated from the deconvolution of the amide I band of adsorbed fibrinogen indicates a good biocompatibility of the substrate. In vitro study shows the bioactive character of bioactive glass with attached fibrinogen, and at the same time severe conformational changes in secondary structures of the adsorbed fibrinogen molecules were identified. These changes were found to be determined by electrostatic interaction between the positive charged site of the protein and negative charges on bioactive glass surface, and, by interaction between protein carboxyls and, the phosphate and calcium ions from simulated body fluid (SBF). The most pronounced conformational modifications were observed in the first three days of immersion in SBF; after seven days of immersion these changes were attenuated. FT-IR imaging measurements were also performed to understand the role played by the attached fibrinogen on the hydroxyapatite (HA) layer formation on the glass surface. The HA layer was observed during the first days in relation to the sample without fibrinogen.