Optimization of Cyanocobalamin (Vitamin B12) Sorption onto Mesoporous Superparamagnetic Iron Oxide Nanoparticles

The techniques used to detect and quantify cyanocobalamin (vitamin B12) vary considerably in terms of detection sensitivity, from the most sensitive, based on radioisotopes and mass spectrometry (MS) with limits of detection (LOD) in fg mL-1, to fluorescence (FL) and surface plasmon resonance (SPR) biosensors with LOD values in the range of a few µg mL-1. For accurate quantification of an analyte present at trace levels in complex biological matrices, a selective separation and enrichment step is required to overcome matrix interferences and ensure sufficient detection sensitivity. In this study, iron oxide magnetic nanoparticles (IONPs) were used for the extraction and initial preconcentration of cyanocobalamin (vitamin B12). In the dependence of the magnetization on the H-field (hysteresis loop), no coercivity and remanence values were found at 300 K, indicating the superparamagnetic properties of the tested IONPs. Perfluorinated acids were used as amphiphilic agents to allow the sorption of cyanocobalamin onto the IONPs. FT-IR/ATR spectroscopy was used to confirm the sorption of cyanocobalamin on the IONPs. The influence of the addition of a homologous series of perfluorinated acids such as trifluoroacetic acid (TFAA), heptafluorobutyric acid (HFBA), and trichloroacetic acid (TCAA) to the extraction mixture was tested considering their type, mass, and time required for effective sorption. The adsorption kinetics and isotherm, described by the Freundlich and Langmuir equations, were analyzed. The maximum adsorption capacity (qm) exceeded 6 mg g-1 and was 8.9 mg g-1 and 7.7 mg g-1 for HFBA and TCAA, respectively, as the most efficient additives. After the desorption process using aqueous KH2PO4 solution, the sample was finally analyzed spectrophotometrically and chromatographically. The IONP-based method was successfully applied for the isolation of cyanocobalamin from human urine samples. The results showed that the developed approach is simple, cheap, accurate, and efficient for the determination of traces of cyanocobalamin in biological matrices.

Characteristics and Antimicrobial Activities of Iron Oxide Nanoparticles Obtained via Mixed-Mode Chemical/Biogenic Synthesis Using Spent Hop (Humulus lupulus L.) Extracts

Iron oxide nanoparticles (IONPs) have many practical applications, ranging from environmental protection to biomedicine. IONPs are being investigated due to their high potential for antimicrobial activity and lack of toxicity to humans. However, the biological activity of IONPs is not uniform and depends on the synthesis conditions, which affect the shape, size and surface modification. The aim of this work is to synthesise IONPs using a mixed method, i.e., chemical co-precipitation combined with biogenic surface modification, using extracts from spent hops (Humulus lupulus L.) obtained as waste product from supercritical carbon dioxide hop extraction. Different extracts (water, dimethyl sulfoxide (DMSO), 80% ethanol, acetone, water) were further evaluated for antioxidant activity based on the silver nanoparticle antioxidant capacity (SNPAC), total phenolic content (TPC) and total flavonoid content (TFC). The IONPs were characterised via UV-vis spectroscopy, scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS) and Fourier-transform infrared (FT-IR) spectroscopy. Spent hop extracts showed a high number of flavonoid compounds. The efficiency of the solvents used for the extraction can be classified as follows: DMSO > 80% ethanol > acetone > water. FT-IR/ATR spectra revealed the involvement of flavonoids such as xanthohumol and/or isoxanthohumol, bitter acids (i.e., humulones, lupulones) and proteins in the surface modification of the IONPs. SEM images showed a granular, spherical structure of the IONPs with diameters ranging from 81.16 to 142.5 nm. Surface modification with extracts generally weakened the activity of the IONPs against the tested Gram-positive and Gram-negative bacteria and yeasts by half. Only the modification of IONPs with DMSO extract improved their antibacterial properties against Gram-positive bacteria (Staphylococcus epidermidis, Staphylococcus aureus, Micrococcus luteus, Enterococcus faecalis, Bacillus cereus) from a MIC value of 2.5-10 mg/mL to 0.313-1.25 mg/mL.

Antimicrobial and Apoptotic Efficacy of Plant-Mediated Silver Nanoparticles

Phytogenically synthesised nanoparticle (NP)-based drug delivery systems have promising potential in the field of biopharmaceuticals. From the point of view of biomedical applications, such systems offer the small size, high surface area, and possible synergistic effects of NPs with embedded biomolecules. This article describes the synthesis of silver nanoparticles (Ag-NPs) using extracts from the flowers and leaves of tansy (Tanacetum vulgare L.), which is known as a remedy for many health problems, including cancer. The reducing power of the extracts was confirmed by total phenolic and flavonoid content and antioxidant tests. The Ag-NPs were characterised by various analytical techniques including UV-vis spectroscopy, scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), Fourier transform infrared (FT-IR) spectroscopy, and a dynamic light scattering (DLS) system. The obtained Ag-NPs showed higher cytotoxic activity than the initial extracts against both human cervical cancer cell lines HeLa (ATCC CCL-2) and human melanoma cell lines A375 and SK-MEL-3 by MTT assay. However, the high toxicity to Vero cell culture (ATCC CCL-81) and human fibroblast cell line WS-1 rules out the possibility of their use as anticancer agents. The plant-mediated Ag-NPs were mostly bactericidal against tested strains with MBC/MIC index ≤4. Antifungal bioactivity (C. albicans, C. glabrata, and C. parapsilosis) was not observed for aqueous extracts (MIC > 8000 mg L^-1), but Ag-NPs synthesised using both the flowers and leaves of tansy were very potent against Candida spp., with MIC 15.6 and 7.8 µg mL^-1, respectively.

Single Nucleotide Polymorphisms of the ERAP1 Gene and Risk of NSCLC: A Comparison of Genetically Distant Populations, Chinese and Caucasian

An effective cytotoxic immune response to neoplastic cells requires efficient presentation of antigenic peptides to T lymphocytes by HLA class I (HLA-I) molecules. The HLA-I-bound peptide repertoire depends on antigen-processing machinery molecules. Aminopeptidase residing in endoplasmic reticulum 1 (ERAP1) trims peptides to the optimal length for HLA-I binding. Single nucleotide polymorphisms (SNPs) in the ERAP1 gene result in changes in aminopeptidase activity and specificity. This may affect susceptibility to cancer. However, non-small cell lung carcinoma (NSCLC) has not been studied in this respect. We compared genotype and haplotype frequencies of four coding, nonsynonymous ERAP1 SNPs, rs26653G > C, rs26618T > C, rs30187C > T, and rs27044C > G, in NSCLC occurring in two genetically distant populations, Chinese and Poles. We found associations of all four SNPs with NSCLC in Chinese but not in Poles. The differences in ERAP1-NSCLC associations might be explained by highly significant differences in SNP genotype frequencies between Chinese and Poles (except for rs26618). In accordance with this, the most frequent ERAP1 haplotypes were distributed differently in cases versus controls in Chinese, but not in Poles. Our findings add to the differences between Orientals and Caucasians in genetics of disease susceptibility.

[Selected endothelial hemostatic markers in patients with peripheral arterial disease after endovascular revascularization and restenosis formation]

Surgical and endovascular revascularization of ischemic legs in patients with peripheral arterial disease (PAD) can damage the arterial wall (endothelial and smooth muscle cells). Hemostatic factors released during endothelial dysfunction can lead to restenosis. 1. Determination of selected endothelial hemostatic factors in PAD patients and a reference group. 2. Prospective observation of new restenosis appearance in PAD patients after endovascular revascularization. 3. Comparison of selected endothelial hemostatic factors between non-restenotic and restenotic PAD patients. 150 PAD patients after endovascular revascularization - 90 men and 60 women, aged 44-88 (mean 65.5) years - were examined. During one-year observation after the revascularization procedures in 38 PAD patients restenosis occurred, when blood samples were also collected. The reference group consisted of 53 healthy persons - 44 men and 9 women, aged 20-56 years. Blood was drawn in the morning into 3.2% sodium citrate at a ratio of 9:1. Tissue factor (TF), tissue factor pathway inhibitor (TFPI), thrombomodulin (TM), von Willebrand factor (vWF) and tissue plasminogen activator (t-PA) were measured in plasma with commercial tests using the enzyme immunoassay. In the plasma of PAD patients after revascularization, the concentrations of TF and vWF were significantly higher, TM lower, TFPI and t-PA similar compared to the reference group. Six months after revascularization the level of TF had increased and vWF had significantly decreased. The endothelial hemostatic factors before and after restenosis did not significantly differ except TF, which after restenosis was higher. Increased TF and vWF levels in PAD patients indicate arterial endothelial cell damage, by atherosclerotic and revascularization processes. In PAD patients with restenosis compared to these patients before restenosis the determined endothelial hemostatic factors, except TF level, did not significantly differ. Perhaps TF participates in restenosis formation.

Tissue factor and other hemostatic parameters in patients with advanced peripheral artery disease after endovascular revascularization - search for hemostatic factors which indicate restenosis

BACKGROUND

In patients with peripheral artery disease (PAD) a hypercoagulable state and thromboembolic complications occur. Revascularization procedures increase this state, sometimes leading to restenosis. Restenosis following balloon angioplasty (PTA)and stent implantation is ≥ 50% of artery stenosis.

OBJECTIVES

To determine the concentration of tissue factor (TF), tissue factor pathway inhibitor (TFPI), thrombin-antithrombin (TAT) complexes, fibrinogen and D-dimers in the blood of patients with PAD after peripheral endovascular revascularization of the lower legs and in PAD patients with restenosis.

MATERIAL AND METHODS

The study included 150 patients with PAD, 90 men and 60 women, aged 44-88 (mean 65.5) years, after successful peripheral angioplasty (PTA) and/or with stenting. During the 6 months after the revascularization procedures, restenosis occurred in 27 patients. The reference group consisted of 53 healthy persons (44 men and 9 women, aged 20-56 years). Blood was drawn in the morning into 3.2% natrium citrate at a ratio of 9 : 1. The concentration of TF, TFPI, TAT complexes and D-dimers were measured in plasma with commercial tests using an enzyme immunoassay. Fibrinogen was determined with coagulometer.

RESULTS

In the plasma of patients with PAD after endovascular revascularization, the concentrations of TF, TAT complexes, fibrinogen and D-dimers were significantly higher compared to the reference group. During the six months of observation, 27 patients developed restenosis. The results of hemostatic factors in patients with restenosis were compared with the same patients before restenosis and the group of 123 PAD patients after endovascular revascularization. TF and fibrinogen levels in the 27 patients with restenosis were significantly higher than in the group of PAD patients before restenosis.

CONCLUSIONS

Statistically significantly higher levels of tissue factor (TF) and fibrinogen in PAD patients with new restenosis, compared to those without restenosis after endovascular revascularization, indicate they can participate in the formation of restenosis.