Publications by authors named "Tomasz Buchwald"

23 Publications

  • Page 1 of 1

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

Spectrochim Acta A Mol Biomol Spectrosc 2021 Sep 10;265:120368. Epub 2021 Sep 10.

Institute of Materials Research and Quantum Engineering, Poznan University of Technology, Poland.

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.
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http://dx.doi.org/10.1016/j.saa.2021.120368DOI Listing
September 2021

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

Materials (Basel) 2021 Sep 2;14(17). Epub 2021 Sep 2.

Institute of Chemical Technology and Engineering, Poznan University of Technology, 60-965 Poznan, Poland.

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.
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http://dx.doi.org/10.3390/ma14175008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8434268PMC
September 2021

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

Sci Rep 2021 08 18;11(1):16711. Epub 2021 Aug 18.

Faculty of Materials Science and Technical Physics, Institute of Materials Research and Quantum Engineering, Poznan University of Technology, Poznań, Poland.

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.
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http://dx.doi.org/10.1038/s41598-021-96093-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8373886PMC
August 2021

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

J Biomed Mater Res B Appl Biomater 2021 Jul 21. Epub 2021 Jul 21.

Institute of Chemical Technology and Engineering, Poznan University of Technology, Poznań, Poland.

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.
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http://dx.doi.org/10.1002/jbm.b.34919DOI Listing
July 2021

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

J Pharm Anal 2021 Jun 15;11(3):364-373. Epub 2020 Aug 15.

Wrocław University of Science and Technology, Faculty of Chemistry, Department of Bioorganic Chemistry, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland.

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.
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http://dx.doi.org/10.1016/j.jpha.2020.07.011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8264463PMC
June 2021

Silica-filled methacrylic composites with extremely high compressive strength.

J Mech Behav Biomed Mater 2021 04 13;116:104319. Epub 2021 Jan 13.

Poznan University of Technology, Institute of Chemical Technology and Engineering, ul. Berdychowo 4, 60-965, Poznań, Poland.

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.
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http://dx.doi.org/10.1016/j.jmbbm.2021.104319DOI Listing
April 2021

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

Sci Rep 2020 11 6;10(1):19289. Epub 2020 Nov 6.

Institute of Chemical Technology and Engineering, Poznań University of Technology, Berdychowo 4, 60-965, Poznan, Poland.

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.
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http://dx.doi.org/10.1038/s41598-020-76360-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7648627PMC
November 2020

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

Sci Rep 2020 10 1;10(1):16352. Epub 2020 Oct 1.

Department of Cell Biology, Institute of Biology Sciences, Maria Curie-Skłodowska University, Lublin, Poland.

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.
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http://dx.doi.org/10.1038/s41598-020-73044-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7529762PMC
October 2020

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

Int J Biol Macromol 2020 Dec 28;165(Pt A):268-278. Epub 2020 Sep 28.

Poznan University of Technology, Faculty of Chemical Technology, Institute of Chemical Technology and Engineering, Berdychowo 4, PL-60965 Poznan, Poland.

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.
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http://dx.doi.org/10.1016/j.ijbiomac.2020.09.191DOI Listing
December 2020

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

Materials (Basel) 2020 Jan 15;13(2). Epub 2020 Jan 15.

Institute of Chemistry and Technical Electrochemistry, Faculty of Chemical Technology, Poznan University of Technology, Berdychowo 4, PL-60965 Poznan, Poland.

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.
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http://dx.doi.org/10.3390/ma13020400DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7014024PMC
January 2020

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

Sci Rep 2019 08 22;9(1):12233. Epub 2019 Aug 22.

Chair and Department of Biology and Genetics, Medical University of Lublin, Lublin, Poland.

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.
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http://dx.doi.org/10.1038/s41598-019-48712-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6706583PMC
August 2019

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

J Exp Zool B Mol Dev Evol 2019 07 26;332(5):158-166. Epub 2019 Jun 26.

Department of Histology and Embryology, Faculty of Veterinary Medicine and Animal Science, Poznan University of Life Sciences, Wojska Polskiego, Poznan, Poland.

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.
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http://dx.doi.org/10.1002/jez.b.22892DOI Listing
July 2019

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

PLoS One 2019 11;14(3):e0212869. Epub 2019 Mar 11.

Department of Genetics and Microbiology, Faculty of Biology and Biotechnology Maria Curie-Skłodowska University, Lublin, Poland.

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.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0212869PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6411149PMC
November 2019

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

Analyst 2019 Feb 2;144(4):1409-1419. Epub 2019 Jan 2.

Poznań University of Technology, Institute of Chemical Technology and Engineering, ul. Berdychowo 4, 60-965 Poznań, Poland.

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.
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http://dx.doi.org/10.1039/c8an01494aDOI Listing
February 2019

Zeolite fillers for resin-based composites with remineralizing potential.

Spectrochim Acta A Mol Biomol Spectrosc 2019 Mar 13;210:126-135. Epub 2018 Nov 13.

Poznan University of Technology, Institute of Chemical Technology and Engineering, ul. Berdychowo 4, 60-965 Poznań, Poland.

The objective of the study is to obtain the modified zeolite powders and to apply these materials as active fillers in the dental composites with the remineralizing potential. Three different synthesis pathways were applied to receive LTA-type (Linde A-type) zeolites. All zeolites were subjected to the ion exchange process and mineralization of surface with hydroxyapatite (HA) layer. As a result a calcium form and surface modified form of these materials were prepared. The effectiveness of each modification process was confirmed by X-ray Diffractometry, Infrared and Raman Spectroscopy. Materials were also characterized by Scanning Electron Microscopy, Energy Dispersive Spectroscopy and nitrogen adsorption/desorption measurements. The remineralizing potential was specified as an ability to release calcium ions during the incubation in saline with the use of Inductively Coupled Plasma-Mass Spectrometry. The obtained zeolite fillers were placed in the organic matrix to create photopolymerizable composites with potential dental applications. The homogeneity of the filler distribution in polymeric matrix was checked by the Raman spectra mapping. Composites containing calcium form of zeolites as well as zeolites with the HA layer proved to have the ability to release calcium ions during incubation in saline in the amount comparable to calcium phosphates-filled composites or even higher than dental glass-filled composites. The ability to release calcium ions, together with good mechanical properties and mass stability testify the suitability of prepared composites in potential dental applications.
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http://dx.doi.org/10.1016/j.saa.2018.11.020DOI Listing
March 2019

Modification of Ti6Al4V surface by diazonium compounds.

Spectrochim Acta A Mol Biomol Spectrosc 2018 Feb 28;191:27-35. Epub 2017 Sep 28.

Institute of Chemical Technology and Engineering, Poznań University of Technology, Berdychowo 4, 60-965 Poznań, Poland. Electronic address:

Ti6Al4V alloy is the most commonly used in orthopedic industry as an endoprosthesis. Ti6Al4V exhibits good mechanical properties, except the abrasion resistance. Surface modification of Ti6Al4V in order to obtain organic layer, and then the attachment of the polymer, can allow for overcoming this problem. The aim of the work was the modification of Ti6Al4V surface by diazonium compounds: salt or cation generated in situ and examine the influence of the reducing agent - ascorbic acid, and the temperature of reaction on modification process. Moreover, the simulated body fluid was used for the assessment of the organic layer stability on Ti6Al4V surface. The evaluation of the modification was carried out using the following methods: Raman microspectroscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy. Higher temperature of modification by 4-hydroxymethylbenzenediazonium cation, provides the largest amount of organic layer on the Ti6Al4V alloy. In the case of the Ti6Al4V modified by Variamine Blue B salt, the amount of organic layer is not dependent on the reaction condition. Moreover, the ascorbic acid and the presence of TiO does not effect on the modification. The modified surface is completely coated with the organic layer which is stable in simulated body fluid.
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http://dx.doi.org/10.1016/j.saa.2017.09.070DOI Listing
February 2018

The effect of bonding system application on surface characteristics of bovine dentin and enamel.

Mater Sci Eng C Mater Biol Appl 2017 Jul 23;76:1224-1231. Epub 2017 Mar 23.

Poznań University of Technology, Institute of Chemical Technology and Engineering, ul. Berdychowo 4, 60-965 Poznań, Poland.

The main objective of this study was to examine the surface changes of bovine teeth hard tissues (dentin and enamel) after surface preparation with the use of commercial 3-component etch-and-rinse bonding system. Surface composition changes, morphology, BET specific surface area and surface energy parameters were examined after etching, application of primer and adhesive. Characteristic of tissues composition was carried out with the use of Raman spectroscopy. Morphological changes were followed by scanning electron microscopy, while specific surface area values were measured by the means of gas porosimetry. For the first time surface energy of prepared teeth hard tissues was studied with the use of inverse gas chromatography. A detailed characteristic of surface parameters of bovine teeth hard tissues was made. Obtained results show that each step of dentin and enamel preparation is reflected in all studied parameters. Application of etchant, primer and adhesive causes an increase of surface activity of all examined tissues, measured as surface energy parameters. Surface parameters changes caused by the application of bonding system are crucial from dentin/enamel - restorative material adhesion point of view.
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http://dx.doi.org/10.1016/j.msec.2017.03.205DOI Listing
July 2017

Localization of Alpha-Keratin and Beta-Keratin (Corneous Beta Protein) in the Epithelium on the Ventral Surface of the Lingual Apex and Its Lingual Nail in the Domestic Goose (Anser Anser f. domestica) by Using Immunohistochemistry and Raman Microspectroscopy Analysis.

Anat Rec (Hoboken) 2017 08 30;300(8):1361-1368. Epub 2017 Mar 30.

Faculty of Technical Physics, Institute of Materials Research and Quantum Engineering, Poznan University of Technology, Poznan, Poland.

The epithelium of the ventral surface of the apex of the tongue in most birds is specified by the presence of the special superficial layer called lingual nail. The aim of the present study is to determine the localization of the alpha-keratin and beta-keratin (corneous beta protein) in this special epithelium in the domestic goose by using immunohistochemistry staining and the Raman spectroscopy analysis. Due to lack of commercially available antibodies to detect beta-keratin (corneous beta protein), the Raman spectroscopy was used as a specific tool to detect and describe the secondary structure of proteins. The immunohistochemical (IHC) detections reveal the presence of alpha-keratin in all layers of the epithelium, but significant differences in the distribution of the alpha-keratin in the epithelial layers appear. The staining reaction is stronger from the basal layer to the upper zone of the intermediate layer. The unique result is weak staining for the alpha-keratin in the lingual nail. Applications of the Raman spectroscopy as a complementary method not only confirmed results of IHC staining for alpha-keratin, but showed that this technique could be used to demonstrate the presence of beta-keratin (corneous beta protein). Functionally, the localization of alpha-keratin in the epithelium of the ventral surface of the lingual apex provides a proper scaffold for epithelial cells and promotes structural integrity, whereas the presence of beta-keratin (corneous beta protein) in the lingual nail, described also as exoskeleton of the ventral surface of the apex, endures mechanical stress. Anat Rec, 300:1361-1368, 2017. © 2017 Wiley Periodicals, Inc.
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http://dx.doi.org/10.1002/ar.23591DOI Listing
August 2017

Experimental and in silico investigations of organic phosphates and phosphonates sorption on polymer-ceramic monolithic materials and hydroxyapatite.

Eur J Pharm Sci 2016 Oct 21;93:295-303. Epub 2016 Aug 21.

Department of Chemical Theory of Drugs, Faculty of Pharmacy, Comenius University, Kalinčiakova 8, 83232 Bratislava, Slovakia.

A method based on experimental and in silico evaluations for investigating interactions of organic phosphates and phosphonates with hydroxyapatite was developed. This quick and easy method is used for determination of differences among organophosphorus compounds of various structures in their mineral binding affinities. Empirical sorption evaluation was carried out using liquid chromatography with tandem mass spectrometry or UV-VIS spectroscopy. Raman spectroscopy was used to confirm sorption of organic phosphates and phosphonates on hydroxyapatite. Polymer-ceramic monolithic material and bulk hydroxyapatite were applied as sorbent materials. Furthermore, a Polymer-ceramic Monolithic In-Needle Extraction device was used to investigate both sorption and desorption steps. Binding energies were computed from the fully optimised structures utilising Density Functional Theory (DFT) at B3LYP/6-31+G(d,p) level. Potential pharmacologic and toxic effects of the tested compounds were estimated by the Prediction of the Activity Spectra of Substances using GeneXplain software.
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http://dx.doi.org/10.1016/j.ejps.2016.08.033DOI Listing
October 2016

Calcium release from experimental dental materials.

Mater Sci Eng C Mater Biol Appl 2016 Nov 26;68:213-220. Epub 2016 May 26.

Poznań University of Technology, Institute of Chemical Technology and Engineering, ul. Berdychowo 4, 60-965 Poznań, Poland.

The calcium release from calcium phosphate-containing experimental dental restorative materials was examined. The possible correlation of ion release with initial calcium content, solubility and degree of curing (degree of conversion) of examined materials was also investigated. Calcium release was measured with the use of an ion-selective electrode in an aqueous solution. Solubility was established by the weighing method. Raman spectroscopy was applied for the determination of the degree of conversion, while initial calcium content was examined with the use of energy-dispersive spectroscopy. For examined materials, the amount of calcium released was found to be positively correlated with solubility and initial calcium content. It was also found that the degree of conversion does not affect the ability of these experimental composites to release calcium ions.
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http://dx.doi.org/10.1016/j.msec.2016.05.116DOI Listing
November 2016

The method of purifying bioengineered spider silk determines the silk sphere properties.

Sci Rep 2016 06 17;6:28106. Epub 2016 Jun 17.

Chair of Medical Biotechnology, Poznan University of Medical Sciences, 61-688 Poznan, Poland.

Bioengineered spider silks are a biomaterial with great potential for applications in biomedicine. They are biocompatible,biodegradable and can self-assemble into films, hydrogels, scaffolds, fibers, capsules and spheres. A novel, tag-free, bioengineered spider silk named MS2(9x) was constructed. It is a 9-mer of the consensus motif derived from MaSp2-the spidroin of Nephila clavipes dragline silk. Thermal and acidic extraction methods were used to purify MS2(9x). Both purification protocols gave a similar quantity and quality of soluble silk; however, they differed in the secondary structure and zeta potential value. Spheres made of these purified variants differed with regard to critical features such as particle size, morphology, zeta potential and drug loading. Independent of the purification method, neither variant of the MS2(9x) spheres was cytotoxic, which confirmed that both methods can be used for biomedical applications. However, this study highlights the impact that the applied purification method has on the further biomaterial properties.
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http://dx.doi.org/10.1038/srep28106DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4911573PMC
June 2016

Surface energy of bovine dentin and enamel by means of inverse gas chromatography.

Mater Sci Eng C Mater Biol Appl 2015 Apr 9;49:382-389. Epub 2015 Jan 9.

Poznan University of Technology, Institute of Chemical Technology and Engineering, ul. Berdychowo 4, 60-965 Poznań, Poland.

Adhesion between tooth tissues and dental fillings depends on the surface energy of both connected materials. Bond strength can be determined directly or indirectly as a work of adhesion on the basis of values of surface energy of these materials. Inverse gas chromatography (IGC) is one of the methods of surface energy examination. In this study the values of total surface energy components of wet and dry teeth fragments (enamel, crown dentin and root dentin) were determined with the use of inverse gas chromatography. Inverse gas chromatography has never been used for investigation of surface energy of natural tooth tissues. Different storage conditions were examined - wet and dry. Different values of surface energy are observed according to the type of tooth tissue (dentin or enamel), occurring place (crown or root) and storage conditions (dry or wet). The effect of tissue type and occurring place was the greatest, while storage conditions were of secondary importance. Surface energy depends on composition of tissue, its surface area and the presence of pores.
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http://dx.doi.org/10.1016/j.msec.2015.01.038DOI Listing
April 2015

Identifying compositional and structural changes in spongy and subchondral bone from the hip joints of patients with osteoarthritis using Raman spectroscopy.

J Biomed Opt 2012 Jan;17(1):017007

Poznan University of Technology, Faculty of Technical Physics, Nieszawska 13a, 60-965 Poznań, Poland.

Raman microspectroscopy was used to examine the biochemical composition and molecular structure of extracellular matrix in spongy and subchondral bone collected from patients with clinical and radiological evidence of idiopathic osteoarthritis of the hip and from patients who underwent a femoral neck fracture, as a result of trauma, without previous clinical and radiological evidence of osteoarthritis. The objectives of the study were to determine the levels of mineralization, carbonate accumulation and collagen quality in bone tissue. The subchondral bone from osteoarthritis patients in comparison with control subject is less mineralized due to a decrease in the hydroxyapatite concentration. However, the extent of carbonate accumulation in the apatite crystal lattice increases, most likely due to deficient mineralization. The alpha helix to random coil band area ratio reveals that collagen matrix in subchondral bone is more ordered in osteoarthritis disease. The hydroxyapatite to collagen, carbonate apatite to hydroxyapatite and alpha helix to random coil band area ratios are not significantly changed in the differently loaded sites of femoral head. The significant differences also are not visible in mineral and organic constituents' content in spongy bone beneath the subchondral bone in osteoarthritis disease.
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http://dx.doi.org/10.1117/1.JBO.17.1.017007DOI Listing
January 2012
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