Relationships of Thickness of Perirenal Fat with Urinary Levels of MCP-1 and NGAL in Patients with Hypertension.

Background: We conducted a study to determine the relationships between perirenal fat (PRF) thickness and urinary levels of monocyte chemoattractant protein-1 (MCP-1) and neutrophil gelatinase-associated lipocalin (NGAL) in patients with hypertension (HTN). Methods: In 338 HTN patients (aged 63.51±12.3 on average), MCP-1 and NGAL levels were studied using enzyme-linked immunosorbent assay (ELISA). To measure PRF thickness, all patients underwent CT scans. Results: We considered PRF thickness ≥1.91 cm as the diagnostic threshold for perirenal obesity. Patients with excessive PRF thickness exhibited significantly lower levels of MCP-1 and NGAL compared with those with PRF thickness ≥1.91 cm: 0.98 pg/mL (interquartile range, 0.21 to 2.05) vs. 2.35 pg/mL (0.37 to 5.22) for MCP-1 and 50.0 pg/mL (48.9 to 67.8) vs. 98.3 pg/mL (68.4 to 187.1) for NGAL. We found a relationship of PRF thickness with both MCP-1 (r=0.46, P<0.05) and NGAL (r=0.53, P<0.05), the levels of which were significantly different in patients with first- and third-stage chronic kidney disease: 0.33 pg/mL (0.21 to 1.35) vs. 4.47 pg/mL (0.23 to 10.81); 50.0 pg/mL (49.4 to 85.5) vs. 126.45 pg/mL (57.5 to 205.15), respectively (P=0.04). Patients with metabolically healthy obesity (MHO) had significantly lower MCP-1 levels than those with metabolically unhealthy obesity (MUHO): 0.65 pg/mL (0.21 to 2.15) vs. 3.28 pg/mL (2.05 to 5.22) (P=0.014). MHO patients showed significantly lower NGAL levels than MUHO patients: 50.0 pg/mL (49.4 to 62.2) vs. 98.3 pg/mL (50.0 to 174.8) (P=0.04). Multiple linear regression analysis revealed significant relationships of MCP-1 with PRF thickness (ß±standard error, 0.41±0.15; P<0.001) and smoking (0.26±0.13; P=0.01) and of NGAL with age (0.45±0.16; P<0.01) and PRF thickness (0.49±0.15; P<0.001). Conclusion: We identified higher concentrations of renal fibrosis markers in patients with perirenal and metabolically unhealthy obesity as well as a link between PRF thickness and MCP-1 and NGAL levels in urine.

Meso-Macroporous Hydroxyapatite Powders Synthesized in Polyvinyl Alcohol or Polyvinylpyrrolidone Media.

Mesoporous hydroxyapatite (HA) is widely used in various applications, such as the biomedical field, as a catalytic, as a sensor, and many others. The aim of this work was to obtain HA powders by means of chemical precipitation in a medium containing a polymer-polyvinyl alcohol or polyvinylpyrrolidone (PVP)-with concentrations ranging from 0 to 10%. The HA powders were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, atomic emission spectroscopy with inductively coupled plasma, electron paramagnetic resonance, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The specific surface area (SSA), pore volume, and pore size distributions were determined by low-temperature nitrogen adsorption measurements, and the zeta potential was established. The formation of macropores in powder agglomerates was determined using SEM and TEM. The synthesis in 10% PVP increased the SSA from 101.3 to 158.0 m2/g, while the ripening for 7 days led to an increase from 112.3 to 195.8 m2/g, with the total pore volume rising from 0.37 to 0.71 cm3/g. These materials could be classified as meso-macroporous HA. Such materials can serve as the basis for various applications requiring improved textural properties and may lay the foundation for the creation of bulk 3D materials using a technique that allows for the preservation of their unique pore structure.

Peculiarities of charge compensation in lithium-doped hydroxyapatite.

Hydroxyapatite (HA) remains one of the most popular materials for various biomedical applications and its fields of application have been expanding. Lithium (Li+) is a promising candidate for modifying the biological behavior of HA. Li+ is present in trace amounts in the human body as an alkaline and bioelectric material. At the same time, the introduction of Li+ into the HA structure required charge balance compensation due to the difference in oxidation degree, and the scheme of this compensation is still an open question. In the present work, the results of the theoretical and experimental study of the Li+-doped HA synthesis are presented. According to X-ray diffraction data, Fourier transform infrared spectroscopy as well as the combination of electron paramagnetic resonance methods, the introduction of Li+ in the amount up to 0.05 mol% resulted in the preservation of the HA structure. Density functional theory calculations show that Li+ preferentially incorporates into the Ca (1) position with a small geometry perturbation. The less probable positioning in the Ca (2) position leads to a drastic perturbation of the anion channel.

Zn-Doped Calcium Magnesium Phosphate Bone Cement Based on Struvite and Its Antibacterial Properties.

The development of magnesium calcium phosphate bone cements (MCPCs) has garnered substantial attention. MCPCs are bioactive and biodegradable and have appropriate mechanical and antimicrobial properties for use in reconstructive surgery. In this study, the cement powders based on a (Ca + Mg)/P = 2 system doped with Zn2+ at 0.5 and 1.0 wt.% were obtained and investigated. After mixing with a cement liquid, the structural and phase composition, morphology, chemical structure, setting time, compressive strength, degradation behavior, solubility, antibacterial activities, and in vitro behavior of the cement materials were examined. A high compressive strength of 48 ± 5 MPa (mean ± SD) was achieved for the cement made from Zn2+ 1.0 wt.%-substituted powders. Zn2+ introduction led to antibacterial activity against Staphylococcus aureus and Escherichia coli strains, with an inhibition zone diameter of up to 8 mm. Biological assays confirmed that the developed cement is cytocompatible and promising as a potential bone substitute in reconstructive surgery.

Effects of Various Ripening Media on the Mesoporous Structure and Morphology of Hydroxyapatite Powders.

Mesoporous hydroxyapatite (HA) materials demonstrate advantages as catalysts and as support systems for catalysis, as adsorbent materials for removing contamination from soil and water, and as nanocarriers of functional agents for bone-related therapies. The present research demonstrates the possibility of the enlargement of the Brunauer-Emmett-Teller specific surface area (SSA), pore volume, and average pore diameter via changing the synthesis medium and ripening the material in the mother solution after the precipitation processes have been completed. HA powders were investigated via chemical analysis, X-ray diffraction analysis, Fourier-transform IR spectroscopy, transmission electron microscopy (TEM), and scanning (SEM) electron microscopy. Their SSA, pore volume, and pore-size distributions were determined via low-temperature nitrogen adsorption measurements, the zeta potential was established, and electron paramagnetic resonance (EPR) spectroscopy was performed. When the materials were synthesized in water-ethanol and water-acetone media, the SSA and total pore volume were 52.1 m2g-1 and 116.4 m2g-1, and 0.231 and 0.286 cm3g-1, respectively. After ripening for 21 days, the particle morphology changed, the length/width aspect ratio decreased, and looser and smaller powder agglomerates were obtained. These changes in their characteristics led to an increase in SSA for the water and water-ethanol samples, while pore volume demonstrated a multiplied increase for all samples, reaching 0.593 cm3g-1 for the water-acetone sample.

Biological activity of silver nanoparticles synthesized with Paenibacillus polymyxa exopolysaccharides.

Recently, there has been increased interest in the synthesis of nanoparticles by using natural polysaccharides. These polysaccharides are eco-friendly, nontoxic, and cheap to prepare. On the other hand, the attention in hydrocolloids and films has significantly enhanced, and their application is very promising in the food, pharmaceutical, perfumery and cosmetics, oil, paper, and textile industries. In this context, the present study is aimed to prepare silver nanoparticles by using viscous and superviscous exopolysaccharides of the rhizobacterium Paenibacillus polymyxa strains, CCM 1465 and 88A, and examined the properties of the resultant nanoparticles. We examined the synthesis and properties of silver nanoparticles under variable synthetic conditions by using exopolysaccharides of the rhizobacteria Paenibacillus polymyxa CCM 1465 and 88A. To prepare nanoparticles, we used different combinations of exopolysaccharide and silver nitrate concentrations: 1-10 mg/mL and 1-40 mM, respectively. The resulting solutions were alkalinized from pH 7.5-12 and heated for 15, 30, and 60 min to determine the optimal synthetic conditions. We found that the exopolysaccharides of strains CCM 1465 and 88A reduced silver ions and acted as nanoparticle stabilizers. The prepared spherical, oval, and triangular particles were stable and ranged in size from 2 to 40 nm, depending on the strain and on the experimental conditions. The nanoparticles showed antibacterial and antifungal activity against Escherichia coli K-12, Pseudomonas aeruginosa 50.3, Bacillus subtilis 26-D, and Fusarium oxysporum. In addition, the nanoparticles were active against SK-MEL-2 human melanoma cells. This finding shows the promise of further research on the exopolysaccharides of P. polymyxa 1465 and 88А in different fields of science, including medicine.

Immunization of Mice with Gold Nanoparticles Conjugated to Thermostable Cancer Antigens Prevents the Development of Xenografted Tumors.

Gold nanoparticles as part of vaccines greatly increase antigen stability, antigen accumulation in the lymph nodes, and antigen uptake by antigen-presenting cells. The use of such particles as part of anticancer vaccines based on heat shock proteins to increase vaccine effectiveness is timely. We prepared and characterized nanoconjugates based on 15-nm gold nanoparticles and thermostable tumor antigens isolated from MH22a murine hepatoma cells. The whole-cell lysate of MH22a cells contained the main heat shock proteins. BALB/c mice were injected with the conjugates and then received transplants of MH22a cells. The highest titer was produced in mice immunized with the complex of gold nanoparticles + antigen with complete Freund's adjuvant. The immunized mice showed no signs of tumor growth for 24 days. They also showed a decreased production of the INF-γ, IL-6, and IL-1 proinflammatory cytokines compared to the mice immunized through other schemes. This study is the first to show that it is possible in principle to use gold nanoparticles in combination with thermostable tumor antigens for antitumor vaccination. Antitumor vaccines based on thermostable tumor antigens can be largely improved by including gold nanoparticles as additional adjuvants.

Influence of Synthesis Conditions on Gadolinium-Substituted Tricalcium Phosphate Ceramics and Its Physicochemical, Biological, and Antibacterial Properties.

Gadolinium-containing calcium phosphates are promising contrast agents for various bioimaging modalities. Gadolinium-substituted tricalcium phosphate (TCP) powders with 0.51 wt% of gadolinium (0.01Gd-TCP) and 5.06 wt% of (0.1Gd-TCP) were synthesized by two methods: precipitation from aqueous solutions of salts (1) (Gd-TCP-pc) and mechano-chemical activation (2) (Gd-TCP-ma). The phase composition of the product depends on the synthesis method. The product of synthesis (1) was composed of ß-TCP (main phase, 96%), apatite/chlorapatite (2%), and calcium pyrophosphate (2%), after heat treatment at 900 °C. The product of synthesis (2) was represented by ß-TCP (main phase, 73%), apatite/chlorapatite (20%), and calcium pyrophosphate (7%), after heat treatment at 900 °C. The substitution of Ca2+ ions by Gd3+ in both ß-TCP (main phase) and apatite (admixture) phases was proved by the electron paramagnetic resonance technique. The thermal stability and specific surface area of the Gd-TCP powders synthesized by two methods were significantly different. The method of synthesis also influenced the size and morphology of the prepared Gd-TCP powders. In the case of synthesis route (1), powders with particle sizes of tens of nanometers were obtained, while in the case of synthesis (2), the particle size was hundreds of nanometers, as revealed by transmission electron microscopy. The Gd-TCP ceramics microstructure investigated by scanning electron microscopy was different depending on the synthesis route. In the case of (1), ceramics with grains of 1-50 µm, pore sizes of 1-10 µm, and a bending strength of about 30 MPa were obtained; in the case of (2), the ceramics grain size was 0.4-1.4 µm, the pore size was 2 µm, and a bending strength of about 39 MPa was prepared. The antimicrobial activity of powders was tested for four bacteria (S. aureus, E. coli, S. typhimurium, and E. faecalis) and one fungus (C. albicans), and there was roughly 30% of inhibition of the micro-organism's growth. The metabolic activity of the NCTC L929 cell and viability of the human dental pulp stem cell study demonstrated the absence of toxic effects for all the prepared ceramic materials doped with Gd ions, with no difference for the synthesis route.

Sensor System Based on a Piezoelectric Resonator with a Lateral Electric Field for Virus Diagnostics.

A sensor system based on a piezoelectric resonator with a lateral electric field in the frequency range 6-7 MHz of the electric field for virus detection is described. Through use of the transmissible virus causing gastroenteritis in pigs and specific antibodies, the possibility of detecting the virus in suspension in real time was determined. It was found that the frequency dependence of the real and imaginary parts of the electrical impedance of such a resonator loaded with a virus suspension changes significantly after the addition of specific antibodies to the suspension. No changes are observed if the antibodies are not specific. Thus, the results obtained illustrate the possibility of detecting viruses in situ, directly in the liquid phase, if the change in the real or imaginary parts of the electrical impedance after the addition of antibodies is used as an analytical signal. The possibility of virus detection in the presence of foreign viral particles has been illustrated.

Proteins and polysaccharides from vegetative mycelium of medicinal basidiomycete Lentinus edodes display cytotoxicity towards human and animal cancer cell lines.

Detection and study of biologically active compounds seems a promising area of research in cancer diagnostics and therapies. The glycoprotein and polysaccharide fractions showing high cytotoxicity towards several human and animal cancer cell lines: A549, Hep-2, HeLa, С6 and SPEV-2 were isolated from basidiomycete Lentinus edodes vegetative mycelium and fruiting body and further characterized. It was found that water-soluble glycoprotein fractions caused the most significant, 70-100% inhibition of metabolic activity of SPЕV-2, А549 and С6 cell lines. The effective concentrations of glycoprotein fractions reducing the viability of cancer cell lines were determined. The protein and subunit composition of fractions was studied; the highly active galactose-specific lectins were found to be present in these fractions. Comparative analysis of transcriptomes of L. edodes vegetative mycelium, fruiting body and primordium revealed the presence of carbohydrate-binding glycoproteins (lectins) specific for each stage of basidiomycete morphogenesis. Histological examination revealed some morphological indicators of immune system activation and the absence of toxic effect on gastro-intestinal mucosa of animals at peroral administration of fungal glycoprotein fractions. Fungal protein and, in particular, lectin preparations derived from L. еdodes vegetative mycelium might be considered as novel prospective tools in cancer diagnostics and therapies.

Acoustical Slot Mode Sensor for the Rapid Coronaviruses Detection.

A method for the rapid detection of coronaviruses is presented on the example of the transmissible gastroenteritis virus (TGEV) directly in aqueous solutions with different conductivity. An acoustic sensor based on a slot wave in an acoustic delay line was used for the research. The addition of anti-TGEV antibodies (Abs) diluted in an aqueous solution led to a change in the depth and frequency of resonant peaks on the frequency dependence of the insertion loss of the sensor. The difference in the output parameters of the sensor before and after the biological interaction of the TGE virus in solutions with the specific antibodies allows drawing a conclusion about the presence/absence of the studied viruses in the analyzed solution. The possibility for virus detection in aqueous solutions with the conductivity of 1.9-900 µs/cm, as well as in the presence of the foreign viral particles, has been demonstrated. The analysis time did not exceed 10 min.

Mesoporous Iron(III)-Doped Hydroxyapatite Nanopowders Obtained via Iron Oxalate.

Mesoporous hydroxyapatite (HA) and iron(III)-doped HA (Fe-HA) are attractive materials for biomedical, catalytic, and environmental applications. In the present study, the nanopowders of HA and Fe-HA with a specific surface area up to 194.5 m2/g were synthesized by a simple precipitation route using iron oxalate as a source of Fe3+ cations. The influence of Fe3+ amount on the phase composition, powders morphology, Brunauer-Emmett-Teller (BET) specific surface area (S), and pore size distribution were investigated, as well as electron paramagnetic resonance and Mössbauer spectroscopy analysis were performed. According to obtained data, the Fe3+ ions were incorporated in the HA lattice, and also amorphous Fe oxides were formed contributed to the gradual increase in the S and pore volume of the powders. The Density Functional Theory calculations supported these findings and revealed Fe3+ inclusion in the crystalline region with the hybridization among Fe-3d and O-2p orbitals and a partly covalent bond formation, whilst the inclusion of Fe oxides assumed crystallinity damage and rather occurred in amorphous regions of HA nanomaterial. In vitro tests based on the MG-63 cell line demonstrated that the introduction of Fe3+ does not cause cytotoxicity and led to the enhanced cytocompatibility of HA.

Synthesis of Silymarin-Gold Nanoparticle Conjugate and Analysis of its Liver-Protecting Activity.

BACKGROUND: The liver disease problem prompts investigators to search for new methods of liver treatment. INTRODUCTION: Silymarin (Sil) protects the liver by reducing the concentration of free radicals and the extent of damage to the cell membranes. A particularly interesting method to increase the bioavailability of Sil is to use synthesized gold nanoparticles (AuNPs) as reagents. The study considered whether it was possible to use the silymarin-AuNP conjugate as a potential liver-protecting drug. METHODS: AuNPs were conjugated to Sil and the liver-protecting activity of the conjugate was examined. Experimental hepatitis and hepatocyte cytolysis after carbon tetrachloride action were used as a model system, and the experiments were conducted with laboratory animals. RESULTS: For the first time, silymarin was conjugated to colloidal gold nanoparticles (AuNPs). Electron microscopy showed that the resultant preparations were monodisperse and that the mean conjugate diameter was 18-30 nm ± 0.5 nm (mean diameter of the native nanoparticles, 15 ± 0.5 nm). In experimental hepatitis in mice, conjugate administration interfered with glutathione depletion in hepatocytes in response to carbon tetrachloride. It also was conducive to an increase in energy metabolism and stimulated the monocyte-macrophage function of the liver. The results were confirmed by the high respiratory activity of the hepatocytes in cell culture. CONCLUSION: We conclude that the silymarin-AuNP conjugate holds promise as a liver-protecting agent in acute liver disease caused by carbon tetrachloride poisoning.

Synthesis of silymarin-selenium nanoparticle conjugate and examination of its biological activity in vitro.

Silymarin (Sil) was conjugated to selenium nanoparticles (SeNPs) to increase Sil bioavailability. The conjugates were monodisperse; the average diameter of the native SeNPs was ~ 20-50 ± 1.5 nm, whereas that of the conjugates was 30-50 ± 0.5 nm. The use of SeNPs to increase the bioavailability of Sil was examined with the MH-22a, EPNT-5, HeLa, Hep-2, and SPEV-2 cell lines. The EPNT-5 (glioblastoma) cells were the most sensitive to the conjugates compared to the conjugate-free control. The conjugates increased the activity of cellular dehydrogenases and promoted the penetration of Sil into the intracellular space. Possibly, SeNPs play the main part in Sil penetration of cells and Sil penetration is not associated with phagocytosis. Thus, SeNPs are promising for use as a Sil carrier and as protective antigens.

In Vitro Properties of Manganese-Substituted Tricalcium Phosphate Coatings for Titanium Biomedical Implants Deposited by Arc Plasma.

Bioactive manganese (Mn)-doped ceramic coatings for intraosseous titanium (Ti) implants are developed. Arc plasma deposition procedure is used for coatings preparation. X-ray Diffraction, Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy, and Electron Paramagnetic Resonance (EPR) methods are applied for coatings characterization. The coatings are homogeneous, composed of the main phase α-tricalcium phosphate (α-TCP) (about 67%) and the minor phase hydroxyapatite (about 33%), and the Mn content is 2.3 wt%. EPR spectroscopy demonstrates that the Mn ions are incorporated in the TCP structure and are present in the coating in Mn2+ and Mn3+ oxidation states, being aggregated in clusters. The wetting contact angle of the deposited coatings is suitable for cells' adhesion and proliferation. In vitro soaking in physiological solution for 90 days leads to a drastic change in phase composition; the transformation into calcium carbonate and octacalcium phosphate takes place, and no more Mn is present. The absence of antibacterial activity against Escherichia coli, Enterococcus faecalis, and Pseudomonas aeruginosa bacteria strains is observed. A study of the metabolic activity of mouse fibroblasts of the NCTC L929 cell line on the coatings using the MTT (dye compound 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test demonstrates that there is no toxic effect on the cell culture. Moreover, the coating material supports the adhesion and proliferation of the cells. A good adhesion, spreading, and proliferative activity of the human tooth postnatal dental pulp stem cells (DPSC) is demonstrated. The developed coatings are promising for implant application in orthopedics and dentistry.

Prospects for the Use of Gold Nanoparticles to Increase the Sensitivity of an Acoustic Sensor in the Detection of Microbial Cells.

The interaction of microbial cells with antibody-gold nanoparticle conjugates in conductive suspensions was experimentally studied by using an acoustic slot-mode sensor. The sensor consisted of a piezoelectric plate with a propagating acoustic wave and a liquid container located above this plate with a given gap. An analysis of the measured parameters of the sensor revealed that the specific interaction of bacterial cells with the conjugates led to a stronger change in the sensor output signal than the specific interaction of bacterial cells with antibodies. The measurements were made for Azospirillum brasilense Sp7 cells in buffer with an initial conductivity of 5-30 µS/cm. The limit of cell detection with the conjugates was 103 cells/mL, and the analysis took about 4 min. The advantage of the sensor is the possibility of repeated use and cleaning of the liquid container without damaging the sensor's elements. These results are promising for use in rapid test systems for the direct detection of microbial cells in actual samples of liquids in medical diagnostics.

Structural and Aggregation Features of a Human κ-Casein Fragment with Antitumor and Cell-Penetrating Properties.

Intrinsically disordered proteins play a central role in dynamic regulatory and assembly processes in the cell. Recently, a human κ-casein proteolytic fragment called lactaptin (8.6 kDa) was found to induce apoptosis of human breast adenocarcinoma MCF-7 and MDA-MB-231 cells with no cytotoxic activity toward normal cells. Earlier, we had designed some recombinant analogs of lactaptin and compared their biological activity. Among these analogs, RL2 has the highest antitumor activity, but the amino acid residues and secondary structures that are responsible for RL2's activity remain unclear. To elucidate the structure-activity relations of RL2, we studied the structural and aggregation features of this fairly large intrinsically disordered fragment of human milk κ-casein by a combination of physicochemical methods: NMR, paramagnetic relaxation enhancement (PRE), Electron Paramagnetic Resonance (EPR), circular dichroism, dynamic light scattering, atomic force microscopy, and a cytotoxic activity assay. It was found that in solution, RL2 exists as stand-alone monomeric particles and large aggregates. Whereas the disulfide-bonded homodimer turned out to be more prone to assembly into large aggregates, the monomer predominantly forms single particles. NMR relaxation analysis of spin-labeled RL2 showed that the RL2 N-terminal region, which is essential not only for multimerization of the peptide but also for its proapoptotic action on cancer cells, is more ordered than its C-terminal counterpart and contains a site with a propensity for α-helical secondary structure.

Sic Parvis Magna: Manganese-Substituted Tricalcium Phosphate and Its Biophysical Properties.

Succeeding in the substitution of pharmaceutical compounds with ions deliverable with the use of resorbable biomaterials could have far-reaching benefits for medicine and economy. Calcium phosphates are known as excellent accommodators of foreign ions. Manganese, the fifth most abundant metal on Earth was studied here as an ionic dopant in ß-tricalcium phosphate (ß-TCP) ceramics. ß-TCP containing different amounts of Mn2+ ions per MnxCa3-x(PO4)2 formula (x = 0, 0.001, 0.01, and 0.1) was investigated for a range of physicochemical and biological properties. The results suggested the role of Mn2+ as a structure booster, not breaker. Mn2+ ions increased the size of coherent X-ray scattering regions averaged across all crystallographic directions and also lowered the temperature of transformation of the hydroxyapatite precursor to ß-TCP. The particle size increased fivefold, from 20 to 100 nm, in the 650-750 °C region, indicating that the reaction of formation of ß-TCP was accompanied by a considerable degree of grain growth. The splitting of the antisymmetric stretching mode of the phosphate tetrahedron occurred proportionally to the Mn2+ content in the material, while electron paramagnetic resonance spectra suggested that Mn2+ might substitute for three out of five possible calcium ion positions in the unit cell of ß-TCP. The biological effects of Mn-free ß-TCP and Mn-doped ß-TCP were selective: moderately proliferative to mammalian cells, moderately inhibitory to bacteria, and insignificant to fungi. Unlike pure ß-TCP, ß-TCP doped with the highest concentration of Mn2+ ions significantly inhibited the growth of all bacterial species tested: Staphylococcus aureus, Salmonella typhi, Escherichia coli, Pseudomonas aeruginosa, and Enterococcus faecalis. The overall effect against the Gram-positive bacteria was more intense than against the Gram-negative microorganisms. Meanwhile, ß-TCP alone had an augmentative effect of the viability of adipose-derived mesenchymal stem cells (ADMSCs) and the addition of Mn2+ tended to reduce the extent of this augmentative effect, but without imparting any toxicity. For all Mn-doped ß-TCP concentrations except the highest, the cell viability after 72 h incubation was significantly higher than that of the negative control. Assays evaluating the effect of Mn2+-containing ß-TCP formulations on the differentiation of ADMSCs into three different lineages-osteogenic, adipogenic, and chondrogenic-demonstrated no inhibitory or adverse effects compared to pure ß-TCP and powder-free positive controls. Still, ß-TCP delivering the lowest amount of Mn2+ seemed most effective in sustaining the differentiation process toward all three phenotypes, indicating that the dose of Mn2+ in ß-TCP need not be excessive to be effective.

Prospects for the use of spherical gold nanoparticles in immunization.

Recent years have seen extremely fast development of new viral nanovaccines and diagnostic agents using nanostructures prepared by biological and chemical synthesis. We used spherical gold nanoparticles (average diameter, 15 nm) as a platform for the antigen for swine transmissible gastroenteritis virus (TGEV). The literature data demonstrate that immunization of animals with the TGEV antigen coupled to gold nanoparticles (GNPs) not only activates antigen-presenting cells but also increases the proliferative activity of splenic lymphoid (antibody-forming) cells. The contents of γ-IFN, IL-1ß, and IL-6 in animals immunized with GNP-antigen conjugates were found to be higher than those in intact animals or in animals given the antigen alone. The increased concentration of IL-1ß in the immunized animals directly correlated with the activity of macrophages and stimulated B cells, which produce this cytokine when activated. The increased concentration of IL-6 indicates that the injected preparations are stimulatory to cellular immunity. Immunization with the TGEV antigen conjugated to GNPs as a carrier activates the respiratory activity of lymphoid cells and peritoneal macrophages, which is directly related to their transforming activity and to the activation of antibody generation. Furthermore, the use of this conjugate allows marked improvement of the structure of the animals' immune organs and restores the morphological-functional state of these organs. The microanatomical changes (increased number of follicles) indicate the activation of the B-dependent zone of the spleen and, consequently, the development of a humoral-type immunological reaction. The degradative processes observed in the animals immunized with TGEV antigen alone are evidence of weak resistance to pathogen attack. These results can be used to develop vaccines against this infection by employing TGEV antigen coupled to gold nanoparticles as a carrier.

Gold is for the mistress, silver for the maid: Enhanced mechanical properties, osteoinduction and antibacterial activity due to iron doping of tricalcium phosphate bone cements.

Self-hardening calcium phosphate cements present ideal bone tissue substitutes from the standpoints of bioactivity and biocompatibility, yet they suffer from (a) weak mechanical properties, (b) negligible osteoinduction without the use of exogenous growth factors, and (c) a lack of intrinsic antibacterial activity. Here we attempt to improve on these deficiencies by studying the properties of self-setting Fe-doped bone-integrative cements containing two different concentrations of the dopant: 0.49 and 1.09 wt% Fe. The hardening process, which involved the transformation of Fe-doped ß-tricalcium phosphate (Fe-TCP) to nanocrystalline brushite, was investigated in situ by continuously monitoring the cements using the Energy Dispersive X-Ray Diffraction technique. The setting time was 20 min and the hardening time 2 h, but it took 50 h for the cement to completely stabilize compositionally and mechanically. Still, compared to other similar systems, the phase transformation during hardening was relatively fast and it also followed a relatively simple reaction path, virtually free of complex intermediates and noisy background. Mössbauer spectrometry demonstrated that 57Fe atoms in Fe-TCP were located in two non-equivalent crystallographic sites and distributed over positions with a strong crystal distortion. The pronounced presence of ultrafine crystals in the final, brushite phase contributed to the reduction of the porosity and thereby to the enhancement of the mechanical properties. The compressive strength of the hardened TCP cements increased by more than twofold when Fe was added as a dopant, i.e., from 11.5 ±â€¯0.5 to 24.5 ±â€¯2.0 MPa. The amount of iron released from the cements in physiological media steadied after 10 days and was by an order of magnitude lower than the clinical threshold that triggers the toxic response. The cements exhibited osteoinductive activity, as observed from the elevated levels of expression of genes encoding for osteocalcin and Runx2 in both undifferentiated and differentiated MC3T3-E1 cells challenged with the cements. The osteoinductive effect was inversely proportional to the content of Fe ions in the cements, indicating that an excessive amount of iron can have a detrimental effect on the induction of bone growth by osteoblasts in contact with the cement. In contrast, the antibacterial activity of the cement in the agar assay increased against all four bacterial species analysed (E. coli, S. enteritidis, P. aeruginosa, S. aureus) in direct proportion with the concentration of Fe ions in it, indicating their key effect on the promotion of the antibacterial effect in this material. This effect was less pronounced in broth assays. Experiments involving co-incubation of cements with cells in an alternate magnetic radiofrequency field for 30 min demonstrated a good potential for the use of these magnetic cements in hyperthermia cancer therapies. Specifically, the population of human glioblastoma cells decreased six-fold at the 24 h time point following the end of the magnetic field treatment, while the population of the bone cancer cells dropped approximately twofold. The analysis of the MC3T3-E1 cell/cement interaction reiterated the effects of iron in the cement on the bone growth marker expression by showing signs of adverse effects on the cell morphology and proliferation only for the cement containing the higher concentration of Fe ions (1.09 wt%). Biological testing concluded that the effects of iron are beneficial from the perspective of a magnetic hyperthermia therapy and antibacterial prophylaxis, but its concentration in the material must be carefully optimized to avoid the adverse effects induced above a certain level of iron concentrations.