[Soluble transferrin receptors and ferritin index in the diagnosis of iron deficiency in patients with spondyloarthritis and anemia].

AIM: To assess the diagnostic value of the detection of soluble transferrin receptors (sTfR) and ferritin index (sTfR/log Fer) in patients with spondyloarthritis (SpA) and anemia for the revealing absolute iron deficiency (ID). MATERIALS AND METHODS: The study included 68 patients with SpA: median age 39 [34; 47] years, men: 38 (55.9%). Hemogram, C-reactive protein levels and ferrokinetics parameters were assessed, including sTfR testing by the method of quantitative enzyme-linked immunosorbent assay (Monobind Inc., USA). We also calculated sTfR/log Fer. Based on ferrokinetics parameters and C-reactive protein levels, chronic disease anemia (CDA), iron deficiency anemia (IDA), or their combination (CDA/IDA) were diagnosed. RESULTS: CDA was diagnosed in 16 patients, CDA/IDA in 32 patients, and 20 patients had no anemia. An increase in sTfR concentration in patients with CDA/IDA (1.7 [1.4; 2.2] mg/L) compared with patients with CDA (1.5 [1.1; 1.7] mg/L, p0.05) was revealed. sTfR/log Fer in patients with CDA/IDA (0.93 [0.82; 1.24]) was higher than in patients with CDA (0.64 [0.48; 0.75], p0.0001). When evaluating the ROC curves, it was found that sTfR levels 1.39 mg/L and sTfR/log Fer levels 0.83 indicate the presence of absolute ID. The area under the ROC curve for sTfR was 0.72 (95% confidence interval 0.600.82, p0.001), for sTfR/log Fer 0.85 (95% confidence interval 0.740.92, p0.001). The sensitivity and specificity of sTfR/log Fer (75 and 83%, respectively) were higher compared with sTfR (53 and 81%, respectively). CONCLUSION: In patients with SpA having CDA/IDA, sTfR and sTfR/log Fer are statistically significantly increased. The results obtained indicate the possibility of diagnosing ID by using these parameters.

Electrostatically stabilized hybrids of carbon and maghemite nanoparticles: electrochemical study and application.

Binary hybrids have been investigated for the past few decades due to the emerging properties of nanoparticle composites. Electrostatically stabilized core-shell nanostructures composed of surface active magnetic nanoparticles (SAMNs) and differently charged carbon nanomaterials display specific electrochemical properties. In this work, a set of binary hybrids that include a new class of magnetic nanoparticles is presented and the electrochemical features of the hybrids are reported. Gallic acid derived carbon dots (GA-CDs), PEG derived graphene dots (PEG-GDs), and quaternized carbon dots (Q-CDs) characterized by different charged groups were used for the preparation of different complexes with SAMNs. Thus, a set of six binary nanomaterials was obtained, and characterized by electrochemical impedance spectroscopy, cyclic voltammetry and chronoamperometry, demonstrating significant differences in the charge transfer resistance, capacitive current, electrochemical performance, and reversibility with respect to the isolated subunits. Among them, the combination of Q-CDs with an excess of SAMNs led to a Q-CD@SAMN hybrid, which displayed peculiar electrocatalytic properties attributable to the influence of the strong electrostatic interactions exerted by Q-CDs on the SAMN surface. Notwithstanding their small fraction (around 1% w/w), Q-CDs oriented the electrocatalysis of SAMNs toward the selective electro-oxidation of polyphenols at low applied potentials (+0.1 V vs. SCE). Finally, the Q-CD@SAMN hybrid was used for the development of a coulometric sensor for polyphenols, composed of a simple carbon paste electrode in a small volume electrochemical flow cell (1 µL), and used for the complete direct electro-oxidation of polyphenols from plant extracts.

Effects of silver nanoparticles on human dermal fibroblasts and epidermal keratinocytes.

Biomedical application of silver nanoparticles (AgNPs) has been rapidly increasing. Owing to their strong antimicrobial activity, AgNPs are used in dermatology in the treatment of wounds and burns. However, recent evidence for their cytotoxicity gives rise to safety concerns. This study was undertaken as a part of an ongoing programme in our laboratory to develop a topical agent for wound healing. Here, we investigated the potential toxicity of AgNPs using normal human dermal fibroblasts (NHDF) and normal human epidermal keratinocytes (NHEK) with the aim of comparing the effects of AgNPs and ionic silver (Ag-I). Besides the effect of AgNPs and Ag-I on cell viability, the inflammatory response and DNA damage in AgNPs and Ag-I-treated cells were examined. The results showed that Ag-I were significantly more toxic than AgNPs both on NHDF and NHEK. Non-cytotoxic concentrations of AgNPs and Ag-I did not induce DNA strand breaks and did not affect inflammatory markers, except for a transient increase in interleukin 6 levels in Ag-I-treated NHDF. The results showed that AgNPs are more suitable for the intended application as a topical agent for wound healing up to the concentration 25 µg/mL.

Quaternized carbon dot-modified graphene oxide for selective cell labelling--controlled nucleus and cytoplasm imaging.

Cationic quaternized carbon dots (QCDs) and anionic graphene oxide sheets (GO) are combined via non-covalent interactions following a self-assembly pathway to form highly biocompatible and fluorescent hybrid materials. These hybrids act as selective probes with controlled labelling of the cell nucleus or cytoplasm depending on the QCD loading.

Thermostable trypsin conjugates immobilized to biogenic magnetite show a high operational stability and remarkable reusability for protein digestion.

In this work, magnetosomes produced by microorganisms were chosen as a suitable magnetic carrier for covalent immobilization of thermostable trypsin conjugates with an expected applicability for efficient and rapid digestion of proteins at elevated temperatures. First, a biogenic magnetite was isolated from Magnetospirillum gryphiswaldense and its free surface was coated with the natural polysaccharide chitosan containing free amino and hydroxy groups. Prior to covalent immobilization, bovine trypsin was modified by conjugating with α-, ß- and γ-cyclodextrin. Modified trypsin was bound to the magnetic carriers via amino groups using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysulfosuccinimide as coupling reagents. The magnetic biomaterial was characterized by magnetometric analysis and electron microscopy. With regard to their biochemical properties, the immobilized trypsin conjugates showed an increased resistance to elevated temperatures, eliminated autolysis, had an unchanged pH optimum and a significant storage stability and reusability. Considering these parameters, the presented enzymatic system exhibits properties that are superior to those of trypsin forms obtained by other frequently used approaches. The proteolytic performance was demonstrated during in-solution digestion of model proteins (horseradish peroxidase, bovine serum albumin and hen egg white lysozyme) followed by mass spectrometry. It is shown that both magnetic immobilization and chemical modification enhance the characteristics of trypsin making it a promising tool for protein digestion.