Detonation nanodiamonds (DND) are a widely studied group of carbon nanomaterials. They have the ability to adsorb a variety of biomolecules and drugs onto their surfaces, and additionally their surfaces may be subjected to chemical functionalization by covalent bonds. We present a procedure for the purification and surface oxidation of diamond nanoparticles, which were then tested by spectroscopic analysis such as ATR-FTIR, Raman spectroscopy, and thermogravimetric analysis. We also examined the zeta potential of the tested material. Analysis of the cytotoxic effect of nanodiamonds against normal lymphocytes derived from human peripheral blood, the non-small cell lung cancer cell line (A549) and the human colorectal adenocarcinoma cell line (HT29) was performed using MTT colorimetric assay. Evaluation of cell viability was performed after 1-h and 24-h treatment with the tested nanoparticles applied at concentrations ranging from 1 μg/ml to 100 μg/ml. We found that the survival of the examined cells was strongly associated with the presence of serum proteins in the growth medium. The incubation of cells with nanodiamonds in the presence of serum did not exert a significant effect on cell survival, while the cell treatment in a serum-free medium resulted in a decrease in cell survival compared to the negative control. The role of purification and functionalization of nanodiamonds on their cytotoxicity was also demonstrated.
- MeSH
- A549 Cells MeSH
- HT29 Cells MeSH
- Cells, Cultured MeSH
- Humans MeSH
- Lymphocytes cytology drug effects metabolism MeSH
- Microscopy, Electron, Scanning MeSH
- Nanodiamonds toxicity ultrastructure MeSH
- Cell Proliferation drug effects MeSH
- Spectrum Analysis, Raman MeSH
- Spectroscopy, Fourier Transform Infrared MeSH
- Cell Survival drug effects MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
Radio frequency plasma is one of the means to modify the polymer surface namely in the activation of polypropylene membranes (PPM) with O2 plasma. Activated membranes were deposited with TiO2 nanoparticles by the dip coating method and the bare sample and modified sample (PPM5-TiO2) were irradiated by UV lamps for 20-120 min. Characterization techniques such as X-ray diffraction (XRD), Attenuated total reflection technique- Fourier transform infrared spectroscopy (ATR-FTIR), Thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), Scanning electron microscope (SEM) and water contact angle (WCA) measurements were applied to study the alteration of ensuing membrane surface properties which shows the nanoparticles on the sample surface including the presence of Ti on PPM. The WCA decreased from 135° (PPM) to 90° (PPM5-TiO2) and after UV irradiation, the WCA of PPM5-TiO2 diminished from 90° to 40°.
- MeSH
- X-Ray Diffraction MeSH
- Photoelectron Spectroscopy MeSH
- Oxygen chemistry MeSH
- Membranes, Artificial * MeSH
- Nanoparticles chemistry MeSH
- Plasma Gases chemistry MeSH
- Polypropylenes chemistry MeSH
- Wettability MeSH
- Spectroscopy, Fourier Transform Infrared MeSH
- Temperature MeSH
- Thermogravimetry MeSH
- Titanium chemistry MeSH
- Water chemistry MeSH
- Publication type
- Journal Article MeSH
The first Fe(III) complexes 1-6 with cyclin-dependent kinase (CDK) inhibitors of the type [Fe(L(n))Cl(3)].nH(2)O (n=0 for 1, 1 for 2, 2 for 3-6; L(1)-L(6)=C2- and phenyl-substituted CDK inhibitors derived from 6-benzylamino-9-isopropylpurine), have been synthesized and characterized by elemental analysis, IR, (57)Fe Mössbauer, (1)H and (13)C NMR, and ES+ mass spectroscopies, conductivity and magnetic susceptibility measurements, and thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The study revealed that the compounds are mononuclear, tetrahedral high-spin (S=5/2) Fe(III) complexes with an admixture of an S=3/2 spin state originating probably from five-coordinated Fe(III) ions either connecting with a bidentate coordination mode of the CDK inhibitor ligand or relating to the possibility that one crystal water molecule enters the coordination sphere of the central atom in a portion of molecules of the appropriate complex. Nearly spin-only value of the effective magnetic moment (5.82micro(eff)/micro(B)) was determined for compound 1 due to absence of crystal water molecule(s) in the structure of the complex. Based on NMR data and DFT calculations, we assume that the appropriate organic ligand is coordinated to the Fe(III) ion through the N7 atom of a purine moiety. The cytotoxicity of the complexes was tested in vitro against selected human cancer cell lines (G-361, HOS, K-562 and MCF-7) along with the ability to inhibit the CDK2/cyclinE kinase. The best cytotoxicity (IC(50): 4-23muM) and inhibition activity (IC(50): 0.02-0.09microM) results have been achieved in the case of complexes 2-4, and complexes 3, 4 and 6, respectively. In addition, the X-ray structure of 2-chloro-6-benzylamino-9-isopropylpurine, i.e. a precursor for the preparation of L(1), L(4) and L(5), is also described.
- MeSH
- Electrochemical Techniques methods MeSH
- Cyclin-Dependent Kinase Inhibitor Proteins chemistry metabolism MeSH
- Humans MeSH
- Models, Molecular MeSH
- Molecular Structure MeSH
- Cell Line, Tumor MeSH
- Antineoplastic Agents chemical synthesis chemistry pharmacology MeSH
- Purines chemistry MeSH
- Drug Screening Assays, Antitumor MeSH
- Spectrum Analysis methods MeSH
- Iron chemistry MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The Pt(II) and Pd(II) complexes of the types cis-[Pt(L(1))(2)Cl(2)].H(2)O (1), cis-[Pt(L(2))(2)Cl(2)].3H(2)O (2), trans-[Pd(L(1))(2)Cl(2)].H(2)O (3), trans-[Pd(L(2))(2)Cl(2)].H(2)O (4), trans-[Pd(L(3))(2)Cl(2)].2DMF (5) and trans-[Pd(L(4))(2)Cl(2)].2DMF (6) (L(1)-L(4)=cyclin-dependent kinase inhibitors derived from 6-benzylamino-9-isopropylpurine) have been prepared and characterized. The complexes have been studied by elemental analyses, conductivity measurements, ES+ MS, FT-IR, (1)H, (13)C and (195)Pt NMR spectra, differential scanning calorimetry and thermogravimetric analysis. The molecular structures of L(1), trans-[Pd(L(3))(2)Cl(2)].2DMF (5) and trans-[Pd(L(4))(2)Cl(2)].2DMF (6) have been determined by single crystal X-ray analysis. The complexes have been tested in vitro due to their presumable anticancer activity against the following human cancer cell lines: K-562, MCF7, G-361 and HOS. Satisfying results were obtained for the complex 1 with IC(50) values of 6 microM acquired against G-361 as well as against HOS cell lines. The lowest values of IC(50) were achieved for the complexes 3 and 4 against MCF 7 cell line with IC(50) 3 microM(for 3) and also 3 microM (for 4).
- MeSH
- Cyclin-Dependent Kinases antagonists & inhibitors MeSH
- Calorimetry, Differential Scanning MeSH
- Financing, Organized MeSH
- Spectrometry, Mass, Electrospray Ionization MeSH
- Enzyme Inhibitors pharmacology chemistry MeSH
- Crystallography, X-Ray MeSH
- Magnetic Resonance Spectroscopy MeSH
- Models, Molecular MeSH
- Palladium pharmacology chemistry MeSH
- Antineoplastic Agents pharmacology chemistry MeSH
- Platinum Compounds pharmacology chemical synthesis chemistry MeSH
- Spectrophotometry, Infrared MeSH
Free radical polymerization technique was used to formulate Poloxamer-188 based hydrogels for controlled delivery. A total of seven formulations were formulated with varying concentrations of polymer, monomer ad cross linker. In order to assess the structural properties of the formulated hydrogels, Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC), Scanning electron microscopy (SEM), and X-ray diffraction (XRD) were carried out. To assess the effect of pH on the release of the drug from the polymeric system, drug release studies were carried in pH 1.2 and 7.4 and it was found that release of the drug was significant in pH 7.4 as compared to that of pH 1.2 which confirmed the pH responsiveness of the system. Different kinetic models were also applied to the drug release to evaluate the mechanism of the drug release from the system. To determine the safety and biocompatibility of the system, toxicity study was also carried out for which healthy rabbits were selected and formulated hydrogels were orally administered to the rabbits. The results obtained suggested that the formulated poloxamer-188 hydrogels are biocompatible with biological system and have the potential to serve as controlled drug delivery vehicles.
- MeSH
- Acrylic Resins * chemistry MeSH
- Calorimetry, Differential Scanning MeSH
- X-Ray Diffraction MeSH
- Hydrogels * chemistry MeSH
- Hydrogen-Ion Concentration MeSH
- Rabbits MeSH
- Drug Delivery Systems MeSH
- Delayed-Action Preparations chemistry pharmacokinetics MeSH
- Microscopy, Electron, Scanning MeSH
- Drug Carriers chemistry MeSH
- Poloxamer * chemistry MeSH
- Spectroscopy, Fourier Transform Infrared MeSH
- Thermogravimetry MeSH
- Timolol * administration & dosage pharmacokinetics chemistry MeSH
- Drug Liberation MeSH
- Animals MeSH
- Check Tag
- Rabbits MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article 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
- Biocompatible Materials chemistry MeSH
- Calorimetry, Differential Scanning MeSH
- Humans MeSH
- Polyethylenes * chemistry MeSH
- Prosthesis Design MeSH
- Knee Prosthesis * MeSH
- Thermogravimetry MeSH
- Materials Testing * methods MeSH
- Arthroplasty, Replacement, Knee * instrumentation methods MeSH
- Check Tag
- Humans MeSH
- Publication type
- English Abstract MeSH
- Journal Article MeSH
- Comparative Study MeSH
This paper reports the substitution of polyolefin backbone binder components with low melting temperature carnauba wax for powder injection moulding applications. The effect of various binder compositions of Al₂O₃ feedstock on thermal degradation parameters is investigated by thermogravimetric analysis. Within the experimental framework 29 original feedstock compositions were prepared and the superiority of carnauba wax over the polyethylene binder backbone was demonstrated in compositions containing polyethylene glycol as the initial opening agent and governing the proper mechanism of the degradation process. Moreover, the replacement of synthetic polymer by the natural wax contributes to an increase of environmental sustainability of modern industrial technologies.
- MeSH
- Cold Temperature * MeSH
- Polymers chemistry MeSH
- Powders chemistry MeSH
- Thermogravimetry MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The aim of this study is to identify the optimum thermal conversion of Chlorella vulgaris with neuro-evolutionary approach. A Progressive Depth Swarm-Evolution (PDSE) neuro-evolutionary approach is proposed to model the Thermogravimetric analysis (TGA) data of catalytic thermal degradation of Chlorella vulgaris. Results showed that the proposed method can generate predictions which are more accurate compared to other conventional approaches (>90% lower in Root Mean Square Error (RMSE) and Mean Bias Error (MBE)). In addition, Simulated Annealing is proposed to determine the optimal operating conditions for microalgae conversion from multiple trained ANN. The predicted optimum conditions were reaction temperature of 900.0 °C, heating rate of 5.0 °C/min with the presence of HZSM-5 zeolite catalyst to obtain 88.3% of Chlorella vulgaris conversion.
- MeSH
- Chlorella vulgaris * MeSH
- Catalysis MeSH
- Microalgae * MeSH
- Neural Networks, Computer MeSH
- Temperature MeSH
- Publication type
- Journal Article MeSH
Monodisperse macroporous poly(glycidyl methacrylate) (PGMA) microspheres were used as a template for preparing porous silica particles. The starting polymer microspheres that were 9.3 microm in size were synthesized by multistep swelling polymerization using a modified Ugelstad technique. Subsequently, silica (SiO2) was deposited on the surface and inside the PGMA microspheres to produce poly(glycidyl methacrylate)-silica hybrid particles (PGMA-SiO2). Upon calcination of the PGMA-SiO2 microspheres, porous silica particles were formed. The morphology, particle size, polydispersity and inner structure of the silica microspheres were investigated by scanning and transmission electron microscopy. Thermogravimetric analysis and dynamic adsorption of nitrogen determined the amount of silica formed and its specific surface area. Compared with the starting PGMA microspheres, the size of the porous silica particles decreased by up to 30%. These porous silica microspheres are promising for chromatography and biomedical applications.
The aim of the study was to compare the adsorption ability of two adsorbent materials, namely diosmectite and activated charcoal towards selected model compounds that are most commonly involved in acute intoxication. Eleven model compounds were selected: acetylsalicylic acid, α-amanitin, amlodipine, digoxin, phenobarbital, ibuprofen, imipramine, carbamazepine, oxazepam, promethazine, and theophylline. Of the tested compounds, promethazine and imipramine were the most effectively adsorbed to diosmectite. Their adsorption to diosmectite (0.356±0.029mg promethazine/mg diosmectite and 0.354±0.019mg imipramine/mg diosmectite, respectively) was significantly higher than their adsorption to activated charcoal. The effect of temperature and pH on the adsorption efficiencies was also evaluated. In the case of experiments with mixture of both adsorbents, they mostly behaved in a solution independently or in a slightly antagonistic way. Using various methods such as N2 adsorption and thermogravimetric analysis, the structure and texture of diosmectite and activated charcoal were attained.
- MeSH
- Adsorption MeSH
- Alpha-Amanitin chemistry MeSH
- Amlodipine chemistry MeSH
- Antidotes chemistry MeSH
- Aspirin chemistry MeSH
- Digoxin chemistry MeSH
- Charcoal chemistry MeSH
- Phenobarbital chemistry MeSH
- Ibuprofen chemistry MeSH
- Imipramine chemistry MeSH
- Carbamazepine chemistry MeSH
- Poisoning prevention & control MeSH
- Oxazepam chemistry MeSH
- Promethazine chemistry MeSH
- Silicates chemistry MeSH
- Theophylline chemistry MeSH
- Publication type
- Journal Article MeSH
- Comparative Study MeSH
