Surface Modification of Ti6Al4V ELI Titanium Alloy by Poly(ethylene-alt-maleic anhydride) and Risedronate Sodium.

With the simultaneous increase in the number of endoprostheses being performed, advances in the field of biomaterials are becoming apparent-whereby the materials and technologies used to construct implants clearly improve the implants' quality and, ultimately, the life of the patient after surgery. The aim of this study was to modify the titanium alloy Ti6Al4V ELI used in the construction of hip joint endoprostheses. This is why the continuous development of biomaterials is so important. This paper presents the results of research for a new application of polymer poly(ethylene-alt-maleic anhydride) as a drug release layer, placed on the surface of a titanium alloy. The obtained layers were analyzed using Raman spectroscopy (spectra and maps), Fourier transform infrared spectroscopy (spectra and maps), contact angle measurements as well as scanning electron microscopy and energy dispersive spectroscopy imaging and topography analysis. The results confirmed that the polymer layer obtained on the plate surface after the alkali heat treatment process is much better-it binds much more polymer and thus the applied drug. In addition, a longer and more gradual release of the drug was observed for the alkali heat treatment modification than for H2O2 solution.

METHODS FOR DIAGNOSING DENTAL CARIES LESIONS.

Tooth decay (dental caries) commonly occurs throughout the world and is one of the most widespread infectious diseases of lifestyle, globally affecting all age groups; up to 90% schoolchildren and almost 100% adults in both developing and developed countries. When left untreated, it can lead to disease outbreaks resulting in advere-health and life-threatening conditions such as endocarditis or sepsis. Undoubtedly, basic measures are thus required in both dental and GP practice to ensure that dental caries are detected early. This article presents the various diagnostic methods used to identify these disease outbreaks.

Chitosan hydrogel modified with lanthanum as a drug delivery system for epigallocatechin gallate: Investigation of hydrogel - drug interaction by FT-IR and Raman spectroscopy.

In the presented work, chitosan hydrogel modified with lanthanum was obtained for the first time. The hydrogel was used as a carrier in the controlled release of epigallocatechin gallate. The work proved the effectiveness of drug sorption by hydrogel and controlled release in simulated body fluids. The drug was released slowly and in a controlled manner from the carrier. The research techniques used in this work (FT-IR spectroscopy and imaging, Raman spectroscopy, SEM/EDS) allowed to confirm the successful retention of EGCG on the hydrogel surface. On the basis of the EDS mapping, it was possible to confirm the even distribution of the lanthanum ions. Using FT-IR imaging, we verified that the drug was evenly distributed on the entire surface of the prepared material. The antifungal effectiveness of the material has been proven on several types of fungi. The research proved that the prepared material is capable of long-term release of the active substance and has antifungal properties. As a result, the prepared material can be successfully used as an implantable hydrogel or a coating in, e.g. titanium implants.

Chitosan modified with lanthanum ions as implantable hydrogel for local delivery of bisphosphonates.

Osteoporosis is a disease that affects many people around the world. One group of drugs used to treat it are bisphosphonates. However, they have poor bioavailability and many side effects. Therefore, research around the world is focused on developing bisphosphonate delivery systems. In this paper, we would like to present the design of a hydrogel material with chitosan matrix modified with lanthanum, that could serve as an implantable hydrogel capable of sustained and slow release of Zoledronate. Various research techniques were used to characterize the materials, and the swelling ratio and water solubility were also tested. The conducted research proved that the prepared hydrogel is capable of the long-term release of the Zoledronate. Thanks to this, the prepared material can be successfully used as an implantable hydrogel or a coating on titanium implants for the local delivery of drugs.

The Mechanism of Wear Reduction in the Ni-CaF2 Composite Material: Raman and Confocal Microscopy Insights.

A powder metallurgy process was used to produce high temperature self-lubricating composites based on Ni, with varying content of calcium fluoride (10 wt.% and 20 wt.%). The wear properties of the samples were investigated by a pin-on-disc test at elevated temperature, up to 600 °C. Aside from standard techniques for the sample characterization, confocal microscopy and micro-Raman spectroscopy were used for the first time for this type of sample. These methods were used to examine the changes in topography and to detect the distribution of the tribofilm on sample surfaces. The addition of solid lubricant particles decreased the coefficient of friction and improved the tribological properties, because of the tribofilm which formed on sample surfaces.

Controlled release of the drug for osteoporosis from the surface of titanium implants coated with calcium titanate.

The most popular drugs used to prevent osteoporosis that causes low mineral density and weakened microstructure of bones are bisphosphonates. Bisphosphonates can be administered in several ways, but each delivery method has drawbacks. Due to this, new methods of their delivery are being sought. Titanium implants coated with calcium titanate were prepared in this work as carriers for bisphosphonates. Such a modification has been proposed in order to improve the therapeutic properties of the implant. Slow release of the drug at a constant level will positively affect the recovery process and osteointegration. Furthermore, the drug will be slowly released very close to the area affected by osteoporosis. These studies were confirmed, using a variety of methods: EDS and XPS (to examine surface modification and drug sorption), Raman mapping (to proof the presence of the drug on the entire surface of the material) and UV-VIS spectroscopy (to determine bisphosphonate sorption and release profile). It was proved that the active substance (sorbed on the implant) could be completely released upon contact with body fluids within a month. The obtained results will allow for the production of endoprostheses dedicated to patients with osteoporosis in the future.

Formation of the octadecylphosphonic acid layer on the surface of Ti6Al4V ELI titanium alloy and analysis using Raman spectroscopy.

Increasing life expectancy, a sedentary lifestyle and bone diseases all contribute to an increasing demand for endoprostheses. Currently, the service life of a knee prosthesis is 10-17 years on average, depending on the patient's weight and activity. In addition, the most common reasons for revision operations after implantation are prosthesis loosening and infections resulting from the lack of implant-bone connection. That is why it is so important to constantly search for new materials or improve the current methods of obtaining biomaterials and modifying their surfaces. The main goal of the research is to improve the bonding of hydroxyapatite (HA) on the surface of titanium alloy, which is used in the construction of endoprostheses. At this stage of the research, octadecylphosphonic acid (ODPA) deposited on the surface of the Ti6Al4V ELI alloy was analyzed. To verify the layer, HA attachment (the precipitation process) was first checked, and then the modified plates were immersed in a synthetic body fluid (SBF) to simulate the conditions in the living organism. At each stage of the study, the samples were analyzed using: SEM, EDS and Raman spectroscopy - spectral measurements and surface mapping were performed. The study were supplemented by the measurements of the contact angle - checking the wettability of the surface, which is important for the analysis of biomaterials and surface roughness measurements by confocal microscopy. The results shows that ODPA it increases the amount of precipitation of HA when dipped in SBF. Another interesting finding is that the addition of ODPA to the annealed titanium alloy restricts the precipitation of HA on its surface.

Novel Polymer Sorbents with Imprinted Task-Specific Ionic Liquids for Metal Removal.

In this paper, the potential of novel polymer sorbents with the imprinted IL-functional group for the removal of Cu(II), Cd(II), and Zn(II) from aqueous solutions was investigated by batch mode. The sorbents were fabricated by direct reaction of the prepared polymer matrix (poly(vinylbenzyl chloride-divinylbenzene), VBC, and poly(vinylbenzyl bromide-divinylbenzene), VBBr) with 1-(3- or 4-pyridyl)undecan-1-one and oxime of 1-(3- or 4-pyridyl)undecan-1-one. The Fourier Transform Infrared Spectroscopy (FT-IR), Raman Spectroscopy (Raman), Thermogravimetric Analysis (TG), Differential Scanning Calorimetry (DSC), and Scanning Electron Microscopy (SEM) techniques were used to show functionality and stability of the sorbents. The materials were also characterized by contact-angle goniometry, X-rayphotoelectron spectroscopy (XPS), and Zeta potential analysis. The removal of Cd(II), Cu(II), and Zn(II) was monitored and optimized under the influence of several operational controlling conditions and factors such as pH, shaking time, temperature, initial metal ions concentration, and counter-ions at the functional group. The results obtained confirmed the very high potential of the sorbents; however, the properties depend on the structure of the functional group. The tested sorbents showed fast kinetics, significant capacity at 25 °C (84 mg/g for the Zn(II) sorption with VBC-Ox4.10, 63 mg/g for the Cd(II) sorption with VBBr-Ox3.10, and 69 mg/g for the Cu(II) sorption with VBC-K3.10), and temperature dependence (even 100% increase in capacity values at 45 °C). The selected sorbent can be regenerated without a significant decrease in the metal removal efficiency.

Metabolic, structural, and proteomic changes in Candida albicans cells induced by the protein-carbohydrate fraction of Dendrobaena veneta coelomic fluid.

The isolated protein-polysaccharide fraction (AAF) from the coelomic fluid of Dendrobaena veneta earthworm shows effective activity against Candida albicans yeast. Fungal cells of the clinical strain after incubation with the active fraction were characterized by disturbed cell division and different morphological forms due to the inability to separate the cells from each other. Staining of the cells with acridine orange revealed a change in the pH of the AAF-treated cells. It was observed that, after the AAF treatment, the mitochondrial DNA migrated towards the nuclear DNA, whereupon both merged into a single nuclear structure, which preceded the apoptotic process. Cells with a large nucleus were imaged with the scanning electron cryomicroscopy (Cryo-SEM) technique, while enlarged mitochondria and the degeneration of cell structures were shown by transmission electron microscopy (TEM). The loss of the correct cell shape and cell wall integrity was visualized by both the TEM and SEM techniques. Mass spectrometry and relative quantitative SWATH MS analysis were used to determine the reaction of the C. albicans proteome to the components of the AAF fraction. AAF was observed to influence the expression of mitochondrial and oxidative stress proteins. The oxidative stress in C. albicans cells caused by the action of AAF was demonstrated by fluorescence microscopy, proteomic methods, and XPS spectroscopy. The secondary structure of AAF proteins was characterized by Raman spectroscopy. Analysis of the elemental composition of AAF confirmed the homogeneity of the preparation. The observed action of AAF, which targets not only the cell wall but also the mitochondria, makes the preparation a potential antifungal drug killing the cells of the C. albicans pathogen through apoptosis.

Determination of bisphosphonates anti-resorptive properties based on three forms of ceramic materials: Sorption and release process evaluation.

There is a strong need to search for more effective compounds with bone anti-resorptive properties, which will cause fewer complications than commonly used bisphosphonates. To achieve this goal, it is necessary to search for new techniques to characterize the interactions between bone and drug. By studying their interaction with hydroxyapatite (HA), this study used three forms of ceramic materials, two of which are bone-stimulating materials, to assess the suitability of new active substances with anti-resorptive properties. In this study, three methods based on HA in loose form, polycaprolactone/HA (a polymer-ceramic materials containing HA), and polymer-ceramic monolithic in-needle extraction (MINE) device (a polymer inert skeleton), respectively, were used. The affinity of risedronate (a standard compound) and sixteen aminomethylenebisphosphonates (new compounds with potential antiresorptive properties) to HA was defined according to the above-mentioned methods. Ten monolithic materials based on 2-hydroxyethyl methacrylate/ethylene dimethacrylate are prepared and studied, of which one was selected for more-detailed further research. Simulated body fluids containing bisphosphonates were passed through the MINE device. In this way, sorption-desorption of bisphosphonates was evaluated using this MINE device. The paper presents the advantages and disadvantages of each technique and its suitability for assessing new active substances. All three methods allow for the selection of several compounds with potentially higher anti-resorptive properties than risedronate, in hope that it reflects their higher bone affinity and release ability.

Silica-filled methacrylic composites with extremely high compressive strength.

SYLOID® 244 has never been applied as a filler in composites with potential dental application. Therefore, the aim of research was to apply this silica in its unmodified and diazonium salt-modified forms in different mass ratios as fillers in light-cured methacrylic composites. The effectiveness of modification process was confirmed with the use of Raman spectroscopy. Methacrylic composites with the modified and unmodified SYLOID® 244, as well as unfilled resin as a control group were prepared. Their basic physicochemical properties, such as depth of cure, mass stability during incubation in saline, flexural and compressive strengths were examined. A positive effect of SYLOID® 244 modification on the properties of the examined composites was also demonstrated. The obtained results proved the high applicability of SYLOID® 244 as a filler in composites with potential dental applications.

Determination of bisphosphonates anti-resorptive properties based on three forms of ceramic materials:Sorption and release process evaluation / 药物分析学报

There is a strong need to search for more effective compounds with bone anti-resorptive properties,which will cause fewer complications than commonly used bisphosphonates.To achieve this goal,it is necessary to search for new techniques to characterize the interactions between bone and drug.By studying their interaction with hydroxyapatite (HA),this study used three forms of ceramic materials,two of which are bone-stimulating materials,to assess the suitability of new active substances with anti-resorptive properties.In this study,three methods based on HA in loose form,polycaprolactone/HA (a polymer-ceramic materials containing HA),and polymer-ceramic monolithic in-needle extraction(MINE) device (a polymer inert skeleton),respectively,were used.The affinity of risedronate (a standard compound) and sixteen aminomethylenebisphosphonates (new compounds with potential anti-resorptive properties) to HA was defined according to the above-mentioned methods.Ten monolithic materials based on 2-hydroxyethyl methacrylate/ethylene dimethacrylate are prepared and studied,of which one was selected for more-detailed further research.Simulated body fluids containing bisphosphonates were passed through the MINE device.In this way,sorption-desorption of bisphosphonates was evaluated using this MINE device.The paper presents the advantages and disad-vantages of each technique and its suitability for assessing new active substances.All three methods allow for the selection of several compounds with potentially higher anti-resorptive properties than risedronate,in hope that it reflects their higher bone affinity and release ability.

Improving the abrasion resistance of Ti6Al4V alloy by modifying its surface with a diazonium salt and attaching of polyurethane.

Commonly used endoprostheses in the orthopedic industry are those made of Ti6Al4V titanium alloy. Unfortunately, this material has low abrasion resistance, and therefore methods of their modification are still sought. A sensible approach is coating the alloy with a layer of a polymer having higher abrasion resistance. The adhesion of polymers to alloy is low, therefore the alloy requires prior modification. In this work, the alloy was modified with three types of diazonium salt and the influence of substituent on the effectiveness of modification was determined. Then, five or ten polyurethane layers were attached to the surface of the modified alloy. Using Raman mapping, the uniform distribution of layers was proved. Layers are stable in simulated human body fluids. The effectiveness of attaching subsequent layers of polyurethane was also confirmed by nanoindentation. The main focus of this work was to improve the wear resistance of the titanium alloy. The obtained results indicate that the titanium alloy with a polyurethane layer has almost ten times lower coefficient of friction compared to pure alloy. Such a low value has not been described in the literature so far. These results are the first step for obtaining endoprostheses with very high abrasion resistance.

Candida albicans cell wall as a target of action for the protein-carbohydrate fraction from coelomic fluid of Dendrobaena veneta.

The protein-polysaccharide fraction (AAF) isolated from the coelomic fluid of the earthworm Dendrobaena veneta destroys C. albicans cells by changing their morphology, disrupting cell division, and leading to cell death. Morphological changes in C. albicans cells induced by treatment with AAF were documented using DIC, SEM, and AFM. Congo Red staining showed that the fungal wall structure was changed after incubation with AAF. The effect on C. albicans cell walls was shown by AFM analysis of the surface roughness of fungal cell walls and changes in the wall thickness were visualized using Cryo-SEM. The FTIR analysis of C. albicans cells incubated with AAF indicated attachment of protein or peptide compounds to the fungal walls. The intact LC-ESI-MS analysis allowed accurate determination of the masses of molecules present in AAF. As shown by the chromatographic study, the fraction does not cross biological membranes. The Cryo-TEM analysis of AAF demonstrated the ability of smaller subunits to combine into larger agglomerates. AAF is thermally stable, which was confirmed by Raman spectroscopy. AAF can be considered as a potential antifungal antibiotic with activity against clinical C. albicans strains.

Lignin-based dual component additives as effective electrode material for energy management systems.

A functional PbO-lignin electrode hydrid material composite was designed and manufactured. Moreover, its connection efficiency was confirmed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). We noted that the superficial layers of PbO combined with layers of the biopolymer and that oxygen atoms present in both materials had influence on the chemical environment of the neighboring compound. Hence, it can be said that the addition of PbO significantly contributes to the improvement of thermal stability of the final inorganic-organic system. In the framework of the study, the dispersive, morphological and structural characteristics were determined using scanning electron microscopy (SEM) and laser diffraction method. Electrochemical studies indicated that the PbO-lignin material exhibits better electrochemical properties compared to PbO without the addition of kraft lignin (increased capacitance, lower charge transfer resistance), as the specific capacitance after 5000 charge/discharge cycles was still at 95% of the initial value. Such promising operating parameters show that this material can be successfully used as an electrode material for energy management systems.

Carbon Fiber and Nickel Coated Carbon Fiber-Silica Aerogel Nanocomposite as Low-Frequency Microwave Absorbing Materials.

Silica aerogel-based materials exhibit a great potential for application in many industrial applications due to their unique porous structure. In the framework of this study, carbon fiber and nickel coated carbon fiber-silica aerogel nanocomposites were proposed as effective electromagnetic shielding material. Herein, the initial oxidation of the surface of carbon fibers allowed the deposition of a durable Ni metallic nanolayer. The fibers prepared in this way were then introduced into a silica aerogel structure, which resulted in obtaining two nanocomposites that differed in terms of fiber volume content (10% and 15%). In addition, analogous systems containing fibers without a metallic nanolayer were studied. The conducted research indicated that carbon fibers with a Ni nanolayer present in the silica aerogel structure negatively affected the structural properties of the composite, but were characterized by two-times higher electrical conductivity of the composite. This was because the nickel nanolayer effectively blocked the binding of the fiber surface to the silica skeleton, which resulted in an increase of the density of the composite and a reduction in the specific surface area. The thermal stability of the material also deteriorated. Nevertheless, a very high electromagnetic radiation absorption capacity between 40 and 56 dB in the frequency range from 8 to 18 GHz was obtained.

Sida hermaphrodita seeds as the source of anti - Candida albicans activity.

Sida hermaphrodita is a perennial herbaceous plant with potential economic importance; however, there is no information about its antimicrobial properties. The aim of our study was to analyze the morphology and metabolic activity of Candida albicans cells after exposure to the extract from S. hermaphrodita seeds, determine its cytotoxicity against human skin fibroblasts and carry out chemical analysis of the extract. Microscopic analysis showed that the crude seed extract (CSE) caused a significant decrease in the metabolic activity of fungal cells, clear cell deformation, and budding disturbances. The analysis of cytotoxicity showed no influence of the extract on the fibroblasts. The CSE and seed extract after dialysis (DSE) were analyzed using electrophoretic, chromatographic, and spectroscopic methods. SDS-PAGE electrophoresis showed the presence of proteins and carbohydrate compounds in the extract. The Raman spectroscopy analysis of the DSE confirmed the presence of proteins, while FTIR analyses revealed the occurrence of albumin-type proteins. The NMR and GC-MS analyses showed the presence of carbohydrates in the seed extract. The MALDI and ESI LC-MS/MS analysis of the CSE and the DSE fractions revealed the occurrence of vicilin-type and plant lipid transfer proteins. The seed extract is a promising formulation to use in C. albicans infections.

Alpha-keratin and corneous beta protein in the parakeratinized epithelium of the tongue in the domestic goose (Anser anser f. domestica).

The parakeratinized epithelium is a common epithelium in the oral cavity in birds and is characterized by the presence of cell nuclei in the cells of the cornified layer. This epithelium covers almost the entire dorsal surface of the tongue in the domestic goose apart of the lingual nail and conical papillae. So far no study has identified the molecular proteins alpha-keratin (IF-keratin) and/or corneous beta protein (CBP), which are responsible for keratinization or cornification processes in the parakeratinized epithelium of domestic geese. The study was performed using immunohistochemical (IHC) methods to identify alpha-keratin. The innovative method of Raman microspectroscopy was used to determine the presence of CBP and specify their percentage in epithelial layers of the parakeratinized epithelium. The results revealed that alpha-keratin is present in the whole parakeratinized epithelium. A strong staining reaction was detected in the basal and intermediate layers and a less strong staining reaction in the cornified layer. Raman microspectroscopy analysis confirmed the presence of alpha-keratin and demonstrated that its percentage decreases from the basal layer to the cornified layer. The Raman microspectroscopy technique revealed the occurrence of CBP in the parakeratinized epithelium and demonstrated that the percentage of this protein increases from the basal layer to the cornified layer. Performed analysis determines that parakeratinized epithelium undergoes cornification. However, the lower percentage of CBP in the cornified layer of parakeratinized epithelium than in orthokeratinized epithelium points to the fact that parakeratinized epithelium has a weaker protective function.

Anti-Candida albicans effect of the protein-carbohydrate fraction obtained from the coelomic fluid of earthworm Dendrobaena veneta.

An antifungal active fraction (AAF) from the coelomic fluid (CF) of the earthworm Dendrobaena veneta was isolated. The aim of the study was to analyze the antifungal activity of the AAF and to carry out chemical characterization of the fraction. The active fraction showed antifungal activity against a clinical C. albicans isolate, C. albicans ATCC 10231, and C. krusei ATCC 6258. It effectively reduced the metabolic activity of C. albicans cells and influenced their morphology after 48 hours of incubation. Scanning electron microscopy (SEM) images revealed loss of integrity of the cell wall induced by the active fraction. Calcofluor White staining showed changes in the structure of the C. albicans cell wall induced by the AAF. The fungal cells died via apoptosis and necrosis after the treatment with the studied fraction. Electrophoresis under native conditions revealed the presence of two compounds in the AAF, while SDS/PAGE gel electrophoresis showed several protein and carbohydrate compounds. The active fraction was analyzed using Raman spectroscopy, MALDI TOF/TOF, and ESI LC-MS. The Raman analysis confirmed the presence of proteins and determined their secondary structure. The MALDI TOF/TOF analysis facilitated detection of four main compounds with a mass of 7694.9 m/z, 12292.3 m/z, 21628.3 m/z, and 42923.2 m/z in the analyzed fraction. The presence of carbohydrate compounds in the preparation was confirmed by nuclear magnetic resonance (NMR) and gas chromatography (GC-MS). The ATR-FTIR spectrum of the AAF exhibited high similarity to the spectrum of egg white lysozyme. The AAF showed no endotoxicity and cytotoxicity towards normal skin fibroblasts (HSF); therefore, it can be used for the treatment of skin and mucous membrane candidiasis in the future. Given its efficient and selective action, the fraction seems to be a promising preparation with antifungal activity against C. albicans.

Assessment of the Raman spectroscopy effectiveness in determining the early changes in human enamel caused by artificial caries.

Current diagnostic methods for enamel caries detection are unable to detect caries lesions at a very early stage. Previous studies indicated that Raman spectroscopy is a promising and effective tool for the detection of early caries. In our previous work, we showed that several independent parameters obtained during the analysis of the Raman spectra of enamel allow for the identification of carious lesions formed in the oral cavity (natural caries). The aim of this research was to estimate the effectiveness of Raman spectroscopy in the determination of specific changes in human enamel affected by artificial caries. The values of parameters obtained in a previous study were compared with those obtained in this work. Moreover, the direction of parameter value changes during caries formation was checked, and also compared with earlier results. The results show that Raman maps permit the determination of local variations in the enamel structure affected by the early demineralization process. As follows from these and previous results a few parameters such as depolarization ratio, polarization anisotropy, position, intensity and full width at half maximum of the Raman band allow for the identification of the enamel caries changes. This investigation contributes to the development of Raman spectroscopy for the identification of caries at a stage before visual changes in enamel.