IR Spectroscopy
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The novel diiron amine complexes [Fe2Cp2(CO)(NH2R')(μ-CO){μ-CN(Me)(Cy)}]CF3SO3 [R' = H, 3; Cy, 4; CH2CH2NH2, 5; CH2CH2NMe2, 6; CH2CH2(4-C6H4OMe), 7; CH2CH2(4-C6H4OH), 8; Cp = η5-C5H5, Cy = C6H11 = cyclohexyl] were synthesized in 49-92 % yields from [Fe2Cp2(CO)2(μ-CO){μ-CN(Me)(Cy)}]CF3SO3, 1a, using a straightforward two-step procedure. They were characterized by IR and multinuclear NMR spectroscopy, and the structure of 7 was confirmed through X-ray diffraction analysis. Complexes 3-8 and the acetonitrile adducts [Fe2Cp2(CO)(NCMe)(μ-CO){μ-CN(Me)(R)}]CF3SO3 (R = Cy, 2a; Me, 2b; Xyl = 2,6-C6H3Me2, 2c) were assessed for their water solubility, octanol-water partition coefficient and stability in physiological-like solutions. The in vitro antiproliferative activity of 2a-c and 3-8 was tested on seven human cancer cell lines (A2780, A2780R, PC3, A549, MCF7, HOS and HT-29), while the selectivity was evaluated using normal MRC-5 cells. Overall, the complexes exhibited variable cytotoxicity, with IC50 values reaching the low micromolar range for 3, 7 and 8 in A2780 and A2780R cells, along with significant selectivity. Targeted experiments covered cell cycle modification, induction of cell death, mitochondrial membrane potential, ROS production and interaction with DNA and bovine serum albumin (BSA) as a model protein. The interaction of 3 with BSA was further investigated through computational studies. Results showed a negligible increase in intracellular ROS levels (except for 2b) and insignificant changes in mitochondrial membrane potential.
- MeSH
- aminy chemie farmakologie MeSH
- komplexní sloučeniny chemie farmakologie chemická syntéza MeSH
- lidé MeSH
- ligandy MeSH
- molekulární struktura MeSH
- nádorové buněčné linie MeSH
- proliferace buněk * účinky léků MeSH
- protinádorové látky * farmakologie chemie chemická syntéza MeSH
- screeningové testy protinádorových léčiv * MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- vztahy mezi strukturou a aktivitou MeSH
- železo chemie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
PURPOSE OF STUDY: Total joint replacements (TJR) have become the cornerstone of modern orthopedic surgery. A great majority of TJR employs ultrahigh molecular weight polyethylene (UHMWPE) liners. TJR manufacturers use many different types of UHMWPE, which are modified by various combinations of crosslinking, thermal treatment, sterilization and/or addition of biocompatible stabilizers. The UHMWPE modifications are expected to improve the polymer's resistance to oxidative degradation and wear (release of microparticles from the polymer surface). This manuscript provides an objective, non-commercial comparison of current UHMWPE formulations currently employed in total knee replacements. MATERIALS AND METHODS: UHMWPE liners from 21 total knee replacements (TKR) were collected which represent the most implanted liners in the Czech Republic in the period 2020-2021. The UHMWPEs were characterized using several methods: infrared microspectroscopy (IR), non-instrumented and instrumented microindentation hardness testing (MH and MHI), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and solubility measurements. The above-listed methods yielded quite complete information about the structure and properties of each UHMWPE type, including its potential long-term oxidation resistance. RESULTS: For each UHMWPE liner, IR yielded information about immediate oxidative degradation (in the form of oxidation index, OI), level of crosslinking (trans-vinylene index, VI) and crystallinity (CI). The MH and MHI testing gave information about the impact of structure changes on mechanical properties. The remaining methods (DSC, TGA, and solubility measurements) provided additional information regarding the structure changes and resistance to long-term oxidative degradation. Statistical evaluation showed significant differences among the samples as well as interesting correlations among the UHMWPE modifications, structural changes, and mechanical performance. DISCUSSION: Surprisingly enough, UHMWPE materials from different manufacturers showed quite different properties, including the resistance against the long-term oxidative degradation, which is regarded as one of the main reasons of TJR failures. The most promising UHMWPE types were crosslinked materials with biocompatible stabilizers. CONCLUSIONS: Current UHMWPE liners from different manufactures used in total knee replacements exhibit significantly different structure and properties. From the point of view of clinical practice, the traditional UHMWPE types, which contained residual radicals from irradiation and/or gamma sterilization, showed inferior resistance to oxidative degradation and should be avoided. The best properties were observed in modern UHMWPE types, which combined crosslinking, biocompatible stabilizers, and sterilization by ethylenoxide or gas plasma. KEY WORDS: UHMWPE; knee replacements; oxidative degradation; infrared spectroscopy; microhardness.
- MeSH
- biokompatibilní materiály chemie MeSH
- diferenciální skenovací kalorimetrie MeSH
- lidé MeSH
- polyethyleny * chemie MeSH
- protézy - design MeSH
- protézy kolene * MeSH
- termogravimetrie MeSH
- testování materiálů * metody MeSH
- totální endoprotéza kolene * přístrojové vybavení metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- srovnávací studie MeSH
BACKGROUND AND AIMS: Prolonged fasting, which leads to the mobilization of fat from adipose tissue, can result in the development of hepatosteatosis. However, it is not yet known whether the accumulation of fat in the liver after fasting can be affected by concurrent obesity. Therefore, this study aimed to assess how excessive adiposity influences changes in liver fat content induced by fasting and subsequent refeeding. METHODS AND RESULTS: Ten lean women and eleven women with obesity (age: 36.4 ± 7.9 and 34.5 ± 7.9 years, BMI: 21.4 ± 1.7 and 34.5 ± 4.8 kg/m2) underwent a 60-h fasting period followed by 2 days of isocaloric high-carbohydrate refeeding. Magnetic resonance spectroscopy (MRS) examinations of liver were conducted at baseline, after 48 h of fasting, and at the end of refeeding period. Hepatic fat content (HFC) increased in lean women after fasting, whereas no statistically significant change in HFC was observed in women with obesity. Additionally, fasting led to significant reductions in liver volume in both groups, likely attributable to glycogen depletion, with subsequent restoration upon refeeding. Notably, changes in hepatic fat volume (HFV) rather than HFC inversely correlated with baseline liver fat content and HOMA-IR. CONCLUSION: We demonstrated that prolonged fasting results in accumulation of fat in the liver in lean subjects only and that this accumulation is inversely related to baseline fat content and insulin resistance. Moreover, the study underscored the importance of evaluating hepatic fat volume rather than hepatic fat content in studies that involve considerable changes in hepatic lean volume.
- MeSH
- adipozita * MeSH
- časové faktory MeSH
- dietní sacharidy aplikace a dávkování MeSH
- dospělí MeSH
- játra * metabolismus diagnostické zobrazování MeSH
- lidé středního věku MeSH
- lidé MeSH
- obezita * patofyziologie terapie metabolismus MeSH
- omezení příjmu potravy * MeSH
- sacharidová dieta škodlivé účinky MeSH
- studie případů a kontrol MeSH
- ztučnělá játra diagnostické zobrazování MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
Restoring the structures and functions of tissues along with organs in human bodies is a topic gathering attention nowadays. These issues are widely discussed in the context of regenerative medicine. Excipients/delivery systems play a key role in this topic, guaranteeing a positive impact on the effectiveness of the drugs or therapeutic substances supplied. Advances in materials engineering, particularly in the development of hydrogel biomaterials, have influenced the idea of creating an innovative material that could serve as a carrier for active substances while ensuring biocompatibility and meeting all the stringent requirements imposed on medical materials. This work presents the preparation of a natural polymeric material based on pullulan modified with silymarin, which belongs to the group of flavonoids and derives from a plant called Silybum marianum. Under UV light, matrices with a previously prepared composition were crosslinked. Before proceeding to the next stage of the research, the purity of the composition of the matrices was checked using Fourier-transform infrared (FT-IR) spectroscopy. Incubation tests lasting 19 days were carried out using incubation fluids such as simulated body fluid (SBF), Ringer's solution, and artificial saliva. Changes in pH, electrolytic conductivity, and weight were observed and then used to determine the sorption capacity. During incubation, SBF proved to be the most stable fluid, with a pH level of 7.6-7.8. Sorption tests showed a high sorption capacity of samples incubated in both Ringer's solution and artificial saliva (approximately 350%) and SBF (approximately 300%). After incubation, the surface morphology was analyzed using an optical microscope for samples demonstrating the greatest changes over time. The active substance, silymarin, was released using a water bath, and then the antioxidant capacity was determined using the Folin-Ciocâlteu test. The tests carried out proved that the material produced is active and harmless, which was shown by the incubation analysis. The continuous release of the active ingredient increases the biological value of the biomaterial. The material requires further research, including a more detailed assessment of its balance; however, it demonstrates promising potential for further experiments.
- MeSH
- glukany * chemie MeSH
- koncentrace vodíkových iontů MeSH
- lékové transportní systémy metody MeSH
- lidé MeSH
- nosiče léků * chemie MeSH
- polyethylenglykoly * chemie MeSH
- silymarin * chemie MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
In an increasingly aging society, there is a growing demand for the development of technology related to tissue regeneration. It involves the development of the appropriate biomaterials whose properties will allow the desired biological response to be obtained. Bioactivity is strongly affected by the proper selection of active ingredients. The aim of this study was to produce bioactive hydrogel materials based on hyaluronic acid and collagen modified by the addition of placenta. These materials were intended for use as dressings, and their physicochemical properties were investigated under simulated biological environmental conditions. The materials were incubated in vitro in different fluids simulating the environment of the human body (e.g., simulated body fluid) and then stored at a temperature close to body temperature. Using an FT-IR spectrophotometer, the functional groups present in the composites were identified. The materials with the added placenta showed an increase in the swelling factor of more than 300%. The results obtained confirmed the potential of using this material as an absorbent dressing. This was indicated by pH and conductometric measurements, sorption, degradation, and surface analysis under an optical microscope. The results of the in vitro biological evaluation confirmed the cytosafety of the tested biomaterials. The tested composites activate monocytes, which may indicate their beneficial properties in the first phases of wound healing. The material proved to be nontoxic and has potential for medical use.
- MeSH
- biokompatibilní materiály farmakologie MeSH
- hojení ran MeSH
- hydrogely * farmakologie chemie MeSH
- kolagen farmakologie chemie MeSH
- kyselina hyaluronová * farmakologie chemie MeSH
- lidé MeSH
- ovce MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
This study reports on the successful use of a machine learning approach using attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy for the classification and prediction of a donor's sex from the fingernails of 63 individuals. A significant advantage of ATR FT-IR is its ability to provide a specific spectral signature for different samples based on their biochemical composition. The infrared spectrum reveals unique vibrational features of a sample based on the different absorption frequencies of the individual functional groups. This technique is fast, simple, non-destructive, and requires only small quantities of measured material with minimal-to-no sample preparation. However, advanced multivariate techniques are needed to elucidate multiplex spectral information and the small differences caused by donor characteristics. We developed an analytical method using ATR FT-IR spectroscopy advanced with machine learning (ML) based on 63 donors' fingernails (37 males, 26 females). The PLS-DA and ANN models were established, and their generalization abilities were compared. Here, the PLS scores from the PLS-DA model were used for an artificial neural network (ANN) to create a classification model. The proposed ANN model showed a greater potential for predictions, and it was validated against an independent dataset, which resulted in 92% correctly classified spectra. The results of the study are quite impressive, with 100% accuracy achieved in correctly classifying donors as either male or female at the donor level. Here, we underscore the potential of ML algorithms to leverage the selectivity of ATR FT-IR spectroscopy and produce predictions along with information about the level of certainty in a scientifically defensible manner. This proof-of-concept study demonstrates the value of ATR FT-IR spectroscopy as a forensic tool to discriminate between male and female donors, which is significant for forensic applications.
Alzheimer's disease (AD) is a progressive brain disorder characterized by extracellular amyloid-β (Aβ) plaques, intracellular neurofibrillary tangles formed by hyperphosphorylated Tau protein and neuroinflammation. Previous research has shown that obesity and type 2 diabetes mellitus, underlined by insulin resistance (IR), are risk factors for neurodegenerative disorders. In this study, obesity-induced peripheral and central IR and inflammation were studied in relation to AD-like pathology in the brains and periphery of APP/PS1 mice, a model of Aβ pathology, fed a high-fat diet (HFD). APP/PS1 mice and their wild-type controls fed either a standard diet or HFD were characterized at the ages of 3, 6 and 10 months by metabolic parameters related to obesity via mass spectroscopy, nuclear magnetic resonance, immunoblotting and immunohistochemistry to quantify how obesity affected AD pathology. The HFD induced substantial peripheral IR leading to central IR. APP/PS1-fed HFD mice had more pronounced IR, glucose intolerance and liver steatosis than their WT controls. The HFD worsened Aβ pathology in the hippocampi of APP/PS1 mice and significantly supported both peripheral and central inflammation. This study reveals a deleterious effect of obesity-related mild peripheral inflammation and prediabetes on the development of Aβ and Tau pathology and neuroinflammation in APP/PS1 mice.
- MeSH
- Alzheimerova nemoc * etiologie MeSH
- amyloidní beta-protein MeSH
- diabetes mellitus 2. typu * MeSH
- dieta s vysokým obsahem tuků škodlivé účinky MeSH
- inzulinová rezistence * MeSH
- myši MeSH
- neurozánětlivé nemoci MeSH
- zánět MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
A series of novel Ga(III)-pyridine carboxylates ([Ga(Pic)3]·H2O (GaPic; HPic = picolinic acid), H3O[Ga(Dpic)2]·H2O (GaDpic; H2Dpic = dipicolinic acid), [Ga(Chel)(H2O)(OH)]2·4H2O (GaChel; H2Chel = chelidamic acid) and [Ga(Cldpic)(H2O)(OH)]2 (GaCldpic; H2Cldpic = 4-chlorodipicolinic acid)) have been synthesized by simple one-step procedure. Vibrational spectroscopy (mid-IR), elemental analysis, thermogravimetric analysis and X-ray diffraction confirmed complexes molecular structure, inter and intramolecular interactions and their influence to spectral and thermal properties. Moreover, complex species speciation was described in Ga(III)-HPic and Ga(III)-H2Dpic systems by potentiometry and 1H NMR spectroscopy and mononuclear complex species were determined; [Ga(Pic)2]+ (logβ021 = 16.23(6)), [Ga(Pic)3] (logβ031 = 20.86(2)), [Ga(Dpic)2]- (logβ021 = 15.42(9)) and [Ga(Dpic)2(OH)]2- (logβ-121 = 11.08(4)). To confirm the complexes stability in 1% DMSO (primary solvent for biological testing), timescale 1H NMR spectra were measured (immediately after dissolution up to 96 h). Antimicrobial activity evaluated by IC50 (0.05 mM) is significant for GaDpic and GaCldpic against difficult to treat and multi-resistant P. aeruginosa. On the other hand, the GaPic complex is most effective against Jurkat, MDA-MB-231 and A2058 cancer cell lines and significantly also decreases the HepG2 cancer cells viability at 75 and 100 μM concentrations in a relatively short time (up to 48 h). In addition, fluorescence measurements have been used to elucidate bovine serum albumin binding activity between ligands, Ga(III) complexes and bovine serum albumin.
Vibrational spectroscopic methods are widely used in the molecular diagnostics of carcinogenesis. Collagen, a component of connective tissue, plays a special role as a biochemical marker of pathological changes in tissues. The vibrational bands of collagens are very promising to distinguish between normal colon tissue, benign and malignant colon polyps. Differences in these bands indicate changes in the amount, structure, conformation and the ratio between the individual structural forms (subtypes) of this protein. The screening of specific collagen markers of colorectal carcinogenesis was carried out based on the FTIR and Raman (λex 785 nm) spectra of colon tissue samples and purified human collagens. It was found that individual types of human collagens showed significant differences in their vibrational spectra, and specific spectral markers were found for them. These collagen bands were assigned to specific vibrations in the polypeptide backbone, amino acid side chains and carbohydrate moieties. The corresponding spectral regions for colon tissues and colon polyps were investigated for the contribution of collagen vibrations. Mentioned spectral differences in collagen spectroscopic markers could be of interest for early ex vivo diagnosis of colorectal carcinoma if combine vibrational spectroscopy and colonoscopy.
- MeSH
- kolagen MeSH
- kolonoskopie * metody MeSH
- kolorektální nádory * diagnóza MeSH
- lidé MeSH
- Ramanova spektroskopie metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
In the present study, a single Arcanobacterium (A.) pinnipediorum strain isolated from discharge of a jaw swelling of a grey seal pup (Halichoerus grypus) in England, UK, was identified. This strain was further characterized by phenotypical investigations, by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), by Fourier transform infrared spectroscopy (FT-IR), and genotypically by sequencing the 16S rRNA gene and the genes gap encoding glyceraldehyde 3-phosphate dehydrogenase, tuf encoding elongation factor tu, and rpoB encoding the β subunit of bacterial RNA polymerase. The present study gives a first detailed characterization of the species A. pinnipediorum from a grey seal in the UK. However, the route of infection of the grey seal with the bacterial pathogen remains unclear.
- MeSH
- Arcanobacterium * genetika MeSH
- RNA ribozomální 16S genetika MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice metody MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- tuleňovití * genetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Spojené království MeSH
