Interaction of Human Dendritic Cells with Graphene Oxide Nanoparticles In Vitro.

We studied the effect of graphene oxide nanoparticles on the differentiation of human dendritic cells and uptake of nanoparticles by these cells in vitro. The objects of the study were mononuclear cells from healthy donors induced into the phenotype of dendritic cells by cytokines (IL-6 and GM-CSF). We used graphene oxide nanoparticles of different sizes functionalized with linear or branched PEG (P-GO or bP-GO) in concentrations of 5 and 25 µg/ml. It was found that graphene oxide nanoparticles did not affect the viability and percentage of dendritic cells in the culture. However, P-GO nanoparticles (25 µg/ml) suppressed the expression of CD83 on the surface of dendritic cells in cultures, thereby suppressing cell differentiation. Dendritic cells internalized P-GO nanoparticles, particles in high concentration were more actively engulfed, but the size of the particles and the type of PEG did not affect the intensity of this process. In general, P-GO nanoparticles in a concentration of 25 µg/ml can regulate differentiation of dendritic cells by suppressing their maturation.

Graphene Oxide Nanoparticels Interaction with Jurkat Cell Line in Cell-IQ System.

In recent years, materials based on graphene oxide (GO) have been actively studied for their use in biomedicine. The aim of our study was to investigate the increase in cell mass and viability of Jurkat tumor line T cells during 24 h of contact with GO nanoparticles in the Cell-IQ system of intravital observation. We used nanoparticles of different sizes coated with linear or branched polyethylene glycol (PEG) at concentrations of 5 and 25 µg/mL. It was shown for the first time that direct contact with GO nanoparticles reduced the growth in cell mass at the visualization points by more than twofold, regardless of nanoparticle size and concentration. Moreover, the number of live cells in the culture decreased by 5-9% after 24 h of monitoring. Thus, PEG-coated GO nanoparticles were found to suppress the proliferation and viability of Jurkat cell line T lymphocytes.

Upconversion Nanoparticles Decorated with Polysialic Acid for Solid Tumors Visualization In Vivo.

Upconversion nanoparticles (UCNPs) are a promising nanoplatform for bioreagent formation for in vivo imaging, which emit UV and blue light under the action of near-infrared radiation, providing deep tissue penetration and maintaining a high signal-to-noise ratio. In the case of solid tumor visualization, the UCNP surface functionalization is required to ensure a long circulation time, biocompatibility, and non-toxicity. The effective UCNP accumulation in the solid tumors is determined by the disturbed architecture of the vascular network and lymphatic drainage. This work demonstrates an approach to the UCNP biofunctionalization with endogenous polysialic acid for in vivo bioreagent formation. Bioreagents possess a low level of nonspecific protein adsorption and macrophage uptake, which allow the prolongation of the circulation time in the bloodstream up to 3 h. This leads to an intense photoluminescent signal in the tumor.

[Influence of antioxidants in native and micelled forms on the shelf life of the emulsion fat product].

Emulsion fat products due to the presence of the aqueous phase are more prone to oxidative damage than pure oils and fats, which requires the use of antioxidants. Based on a social request for the use of natural antioxidants in the food industry, tocopherols, their mixtures, as well as ascorbic acid are widespread. However, most natural antioxidants (vitamins, plant extracts) have lower antioxidant activity in fats than synthetic ones and require more incorporation into the product, which can negatively affect its organoleptic properties and the cost of the finished emulsion fat product. One way to solve this problem is to use new micellized forms of antioxidants. The micellization of various types of waterand fat-soluble antioxidants can increase their specific activity, which is apparently associated with an increase in the relative interaction surface in the product. The development of emulsion fat products using new technological forms of natural antioxidants in order to increase their shelf life is relevant and practically significant for the food industry. The aim of the study was a comparative assessment of the effectiveness of natural antioxidants in native and micellized forms in the margarine formulation. Material and methods. Antioxidants (tocopherols, rosemary extract and ascorbic acid) in the native and micellized forms were selected as objects of the study for their introduction into margarine with a mass fraction of fat of 82%. Peroxide Value and p-anizidin Value were determined in dynamics during storage of margarine in its fatty phase. Results. Experimental data have been obtained on the action of the studied antioxidants in various technological forms on the formation of primary and secondary oxidation products in margarine during storage at the temperature 23±3 °Ð¡. It was determined that the introduction of micellized forms of various antioxidants into margarine at a concentration of 0.015-0.03% most effectively slows down the formation of oxidation products compared to using their native forms in an amount equivalent to the active substances. Conclusion. It has been experimentally established that the use of micellized forms of tocopherols, ascorbic acid and rosemary extract allows more efficient creation of emulsion fat products with an extended shelf life.

Effect of Graphene Oxide Nanoparticles on Differentiation of Myeloid Suppressor Cells.

We studied the effect of graphene oxide (GO) nanoparticles on differentiation of human myeloid suppressor cells (MDSC) in an in vitro system. Separated mononuclear cells of healthy donors were induced with cytokines (IL-6 and GM-CSF) into the MDSC phenotype (both polymorphonuclear (PMN-MDSC) and monocyte (M-MDSC) subsets of these cells were taken into account). Pegylated GO nanoparticles (GO-PEG; mean size 569±14 nm, PEG content ~20%) were used. GO-PEG in low concentrations (2.5 and 5 µg/ml) increased the percentage of MDSC in cultures, but reduced their content in high concentration (10 µg/ml). After exposure to GO-PEG (2.5 and 5 µg/ml), the MDSC content increased at the expense of M-MDSC, while the level of PMN-MDSC did not change. The decrease in MDSC levels after exposure to high doses of GO-PEG (10 µg/ml) was due to a decrease in PMN-MDSC. Thus, GO-PEG nanoparticles can oppositely regulate differentiation of MDSC by inhibiting or stimulating differentiation of these cells depending on the concentration.

[Influence of different type of toothbrushes on gingival fluid proteolytic potential during orthodontic treatment]. / Vliyanie zubnykh shchetok razlichnogo tipa na proteoliticheskii potentsial desnevoi zhidkosti v dinamike ortodonticheskogo lecheniya.

THE AIM: To study the effect of toothbrushes of various types on the accumulation of plaque and the proteolytic potential of gingival fluid as a pathogenic factors in long-term orthodontic treatment of patients with a distal permanent bite. MATERIAL AND METHODS: We examined 63 patients of both sexes aged 11-18 years. Orthodontic treatment was carried out for the close position of the teeth with a distal permanent bite (K07.2) and cleft palate and lips (Q37.1). Patients were divided into three groups depending on the type of toothbrush used for individual oral hygiene: group 1 (n=21) - an orthodontic manual toothbrush (Professor Persin, «Spazzolificio Piave¼, Italy); Group 2 (n=22) - an ultrasonic toothbrush (Emmi-dent, EMAG AG, Germany) and group 3 (n=20) - an electric toothbrush ("Oral-B Pro-Expert, «Procter & Gamble¼, USA). RESULTS: The amount of soft plaque was assessed by the Silness-Loe hygiene index in the subgingival region. The activity of proteolytic enzymes - elastase, collagenase, and a α-inhibitor of proteinases was determined by the enzymatic method using a XL 200 biochemical analyzer («Erba Lachema¼, Czech Republic). The accumulation of plaque in the gingival region on both jaws during the entire period of orthodontic treatment is most pronounced when using a manual brush compared to ultrasonic and electric brushes. An increase in proteolytic activity in the gingival fluid with a simultaneous decrease in antiprotease potential with long-term orthodontic treatment of patients was observed when using a manual orthodontic brush, which can be regarded as an increase in the activity of the pathogenic factors for the development of local inflammatory and destructive changes. CONCLUSION: To prevent inflammatory and destructive changes during prolonged orthodontic treatment of patients, the use of ultrasonic and electric toothbrushes in daily oral hygiene is justified.

[Influence of different type of toothbrushes on the incidence of enamel demineralization and gingivitis in the course of orthodontic treatment]. / Vliyanie ispol'zovaniya zubnykh shchetok razlichnogo tipa na veroyatnost' razvitiya demineralizatsii emali i gingivita v khode ortodonticheskogo lecheniya.

The aim of the study was to determine the likelihood and frequency of complications, the impact of the use of various types of toothbrushes in the dynamics of orthodontic treatment with fixed appliances in patients with a distal permanent bite. The clinical study was conducted on 63 patients of both sexes, aged 11-18 years. Patients received long-term orthodontic treatment for a close tooth position with a distal permanent bite (K07.2) and cleft palate and lip (Q37.1). Three groups were conditionally distinguished depending on the type of toothbrush used for individual oral hygiene: group 1 (n=21) - an orthodontic manual toothbrush (Professor Persin, Spazzolificio Piave S.p.A, Italy); Group 2 (n=22) - an ultrasonic toothbrush (Emmi-dent, EMAG AG, Germany) and group 3 (n=20) - an electric toothbrush (Oral-B Pro-Expert, Procter & Gamble, USA). According to the Kaplan-Meier method, the probability of developing complications of orthodontic treatment was calculated as patients wear braces, and the impact on the effectiveness of orthodontic treatment of using toothbrushes of various types was evaluated. A frequency analysis of the complications of orthodontic treatment for the entire period of wearing fixed orthodontic structures revealed a difference only in respect to enamel demineralization. In group 1, enamel demineralization was more common (42.9%) compared with 2 (9.1%) and 3 (25%) groups (p=0.039). The likelihood of developing gingivitis was higher in group 1, the timing of the development of inflammatory processes in periodontium was also shortened in group 1 compared with groups 2 and 3. The frequency and timing of the development of gingivitis and enamel demineralization depended on the type of toothbrush used in daily oral hygiene. A marked deterioration in the oral hygiene during orthodontic treatment using a manual brush was accompanied by a more frequent development of gingivitis and enamel demineralization.

[Prevention of complications in patients with cleft lip and palate combined with teeth crowding receiving long-term orthodontic treatment]. / Profilaktika razvitiya oslozhnenii pri dlitel'nom ortodonticheskom lechenii patsientov s rasshchelinoi neba i guby, sochetayushcheisya so skuchennym polozheniem zubov.

This study aim was to improve the effectiveness of treatment of patients with cleft lip and palate in combination with crowding of teeth receiving long-term orthodontic treatment. The study involved 30 patients divided in 3 groups in which chlorhexidine-containing medication was included in the individual prevention and treatment program. The effectiveness of using 0.2% CG gel was assessed after 6 months to control the development of inflammatory phenomena in periodontal tissues during long-term orthodontic treatment. The obtained clinical and laboratory data indicate the normalization of the cytokine profile and oral hygiene indices as a result of using a CG-containing preparation for effective control of the biofilm etiological factor.

Ultraviolet phototoxicity of upconversion nanoparticles illuminated with near-infrared light.

Recently introduced upconversion nanoparticles (UCNPs) have pushed the depth of photodynamic therapy (PDT) treatment to the centimetre range by converting deeply-penetrating near-infrared (NIR) radiation to visible radiation for photoexcitation of PDT drugs. Here we demonstrate that the direct exposure of the cancer tissue to phototoxic ultraviolet radiation generated by NIR-photoexcited UCNPs enabled successful PDT. To this aim, core/shell UCNPs of the formula NaYF4:Yb3+Tm3+/NaYF4 featuring an enhanced band in the ultraviolet UV-A and UV-B spectral bands were rationally designed and synthesised. Coupling UCNPs to the recombinant modules of the Designed Ankyrin Repeat Protein (DARPin) fused to a fluorescent protein mCherry allowed the target delivery of DARPin-mCherry/UCNP to human breast adenocarcinoma SK-BR-3 cells overexpressing HER2/neu receptors, as confirmed by fluorescence microscopy. DARPin-mCherry/UCNPs were demonstrated to be phototoxic to SK-BR-3 cells under 975 nm laser irradiation at a dose of 900 J cm-2 due to the UV photoexcitation of endogenous photosensitizers and concomitant generation of reactive oxygen species. The Lewis lung cancer mouse model was employed to demonstrate the feasibility of PDT using UCNP-mediated UV excitation of endogenous photosensitizers in the tumor tissue at a NIR dose of 1200 J cm-2. This study paves the way for exploring and harnessing UV photoexcitation processes in deep tissues in vivo.

Riboflavin photoactivation by upconversion nanoparticles for cancer treatment.

Riboflavin (Rf) is a vitamin and endogenous photosensitizer capable to generate reactive oxygen species (ROS) under UV-blue irradiation and kill cancer cells, which are characterized by the enhanced uptake of Rf. We confirmed its phototoxicity on human breast adenocarcinoma cells SK-BR-3 preincubated with 30-µM Rf and irradiated with ultraviolet light, and proved that such Rf concentrations (60 µM) are attainable in vivo in tumour site by systemic intravascular injection. In order to extend the Rf photosensitization depth in cancer tissue to 6 mm in depth, we purpose-designed core/shell upconversion nanoparticles (UCNPs, NaYF4:Yb3+:Tm3+/NaYF4) capable to convert 2% of the deeply-penetrating excitation at 975 nm to ultraviolet-blue power. This power was expended to photosensitise Rf and kill SK-BR-3 cells preincubated with UCNPs and Rf, where the UCNP-Rf energy transfer was photon-mediated with ~14% Förster process contribution. SK-BR-3 xenograft regression in mice was observed for 50 days, following the Rf-UCNPs peritumoural injection and near-infrared light photodynamic treatment of the lesions.

Submicron polyacrolein particles in situ embedded with upconversion nanoparticles for bioassay.

We report a new surface modification approach of upconversion nanoparticles (UCNPs) structured as inorganic hosts NaYF4 codoped with Yb(3+) and Er(3+) based on their encapsulation in a two-stage process of precipitation polymerization of acrolein under alkaline conditions in the presence of UCNPs. The use of tetramethylammonium hydroxide both as an initiator of acrolein polymerization and as an agent for UCNP hydrophilization made it possible to increase the polyacrolein yield up to 90%. This approach enabled the facile, lossless embedment of UCNPs into the polymer particles suitable for bioassay. These particles are readily dispersible in aqueous and physiological buffers, exhibiting excellent photoluminescence properties, chemical stability, and also allow the control of particle diameters. The feasibility of the as-produced photoluminescent polymer particles mean-sized 260 nm for in vivo optical whole-animal imaging was also demonstrated using a home-built epi-luminescence imaging system.

Visualization of upconverting nanoparticles in strongly scattering media.

Optical visualization systems are needed in medical applications for determining the localization of deep-seated luminescent markers in biotissues. The spatial resolution of such systems is limited by the scattering of the tissues. We present a novel epi-luminescent technique, which allows a 1.8-fold increase in the lateral spatial resolution in determining the localization of markers lying deep in a scattering medium compared to the traditional visualization techniques. This goal is attained by using NaYF4:Yb(3+)Tm(3+)@NaYF4 core/shell nanoparticles and special optical fiber probe with combined channels for the excitation and detection of anti-Stokes luminescence signals.

Specific visualization of tumor cells using upconversion nanophosphors.

The development of targeted constructs on the basis of photoluminescent nanoparticles with a high photo- and chemical stability and absorption/emission spectra in the "transparency window" of biological tissues is an important focus area of present-day medical diagnostics. In this work, a targeted two-component construct on the basis of upconversion nanophosphors (UCNPs) and anti-tumor 4D5 scFv was developed for selective labeling of tumor cells overexpressing the HER2 tumor marker characteristic of a number of human malignant tumors. A high affinity barnase : barstar (Bn : Bs) protein pair, which exhibits high stability in a wide range of pH and temperatures, was exploited as a molecular adapter providing self-assembly of the two-component construct. High selectivity for the binding of the two-component 4D5 scFv-Bn : UCNP-Bs construct to human breast adenocarcinoma SK-BR-3 cells overexpressing HER2 was demonstrated. This approach provides an opportunity to produce similar constructs for the visualization of different specific markers in pathogenic tissues, including malignant tumors.

[Interaction of the dietary fibers with different functional food ingredients].

The aspects of dietary fibers' and different food ingredients' interaction are considered in this article; in particular, the questions of dietary fibers' interaction with the main foodstuff components (proteins, fats, vitamins, etc.), especially functional purpose; and the interaction of microcrystalline cellulose (MCC), which is part of dietary fiber, with the main foodstuff components--protein, vitamins and antioxidants (tocopherol, and riboflavin). It was found that with increasing of MCC content in the diet, there was increase of vitamins sorption (especially tocopherol), with its maximum at 3 g of MCC. This is probably due to the relatively high porosity and properties of MCC to absorb and retain water, lipids and other food ingredients. These findings point to the need to consider the possibility of sorption of polysaccharides and, in particular in the preparation of starch-rich foods and dietary recommendations for their use.

[Combined pectin containing drugs in the treatment of intestinal insufficiency syndrome].

Effectiveness employment of reseach pectin containing drug for enterosoption cause content pectin substances (5-7%), and protein-carbonic complex-balanced and presence such a important immunecorrects, as arginin and glutamic asid, probiotic of metabiotic type establish nutritive support in enteric insufficiency syndrome treatment. There was marked a beneficial effect during using pectin containing drug in the postoperative treatment of intestinal insufficiency, as was confirmed by evaluation of biopsy specimens of gastric mucosa, jejunum and sigmoid colon. Morphologically, it was expressed in chronic inflammation without acute manifestations.

[Endovascular methods of treatment for acute thromboses of lower limb arteries].

The article exemplifies that a group of patients presenting with acute thrombosis of lower- limb arteries appears to belong to the severest patient cohort, whose treatment remains a difficult task for a vascular surgeon, since the solution of this problem cannot be limited to thrombectomy alone, and in the overwhelming majority of cases should be completed by removing the cause of thrombogenesis, to put it more precisely, by a reconstructive vascular operation, for instance, thromboendarterectomy (bypass grafting, prosthetic repair reconstruction), or by an endovascular procedure. All this taken into consideration compels the investigators to search for safer, minimally invasive and at the same time efficient methods of treatment. Endovascular methods aimed at restoration of the arterial lumen meet these requirements to a considerable degree. To endovascular methods of treatment for acute thromboses belong the techniques of aspiration thrombectomy, fibrinolytic thrombolysis, mechanical thrombectomy, rotational, rheolytic thrombectomy, stent-grafting or balloon angioplasty. The policy of fibrinolytic thrombolysis has found rather a wide application in clinical practice. However, the use of this technique is also limited due to a variety of currently existing large disadvantages: a long list of contraindications, labour-consuming and demanding nature of the procedure (requiring to be performed 6-12 hours after the onset of the symptoms of the disease, and check-up angiography within 24-48 hours) as well as rather a high rate of early haemorrhagic complications rate (up to 10-5%). The technique of rotation mechanical thrombectomy has for a long time remained insufficiently claimed for and used more frequently in experimental activity due to the presence of a series of risk factors limiting its application (a high risk of embolism of the distal portion, haemolysis, and a vascular injury). Currently, with the advent of the devices combining rotor fragmentation with simultaneous aspiration of the thrombotic masses (Rotcirex), this method of endovascular treatment is a promising technique requiring further development and widespread use in clinical practice.

[Repeat endovascular interventions after transjugular intrahepatic portosystemic shunt (tips) procedures].

The authors share their experience with transjugular intrahepatic portosystemic shunt (TIPS) procedures preformed in a total of fifty-nine patients diagnosed with and hence operated on for class B and C hepatocirrhosis (according to the Child-Turcotte-Pugh classification), portal hypertension, grade 3 varicosely dilated oesophageal veins, or ascites. Of these, there were 12 women and 47 men (average age 56.3 years). Three types of stents were used: matrix stents (PERICO), self-expanding (ZA-stents, OptiMedsinus-SuperFlex- Visualstents, Zilverstents, SMART), and coated self-expanding stents (Gore Viatorr TIPS Endoprosthesis). Six (11 %) TIPS procedures ended in failure. Of the remaining 53 successful TIPS attempts, thirteen patients developed an in-stent thrombosis at various terms postoperatively, with one patient having experienced it twice Within four postoperative days, thrombosis occurred in three patients, at terms varying from one month to three months in five patients, and from 6 to 12 months in a further five patients. More often thromboses were encountered with the matrix stents (n = 3) 23.0% (PERICO) and self-expanding stents (n = 8) in 61.0% (OptiMed sinus-SuperFlex-Visual). Thromboses were clinically manifested by oesophageal variceal haemorrhage. An in-stent thrombosis was confirmed by means of ultrasonographic duplex scanning (lack of arterial blood flow). The primary stent patency rate following TIPS procedures amounted to 67%. with the secondary assisted graft patency rate equalling 89%. Restoration of the stent's lumen after TIPS procedures by means of endovascular recanalization, rheolytic thrombectomy, balloon angioplasty, and a stent-in-stent technique appears to be a minimally invasive, rather efficient method and virtually the only way to preserve the stent's patency. This technique makes it possible to decrease the rate of recurrent oesophageal variceal haemorrhage.

[New amphiphilic chlorins in the chlorophyll a series].

We treated with nucleophiles derivatives of chlorophyll a with additional six-membered cycles: delta-lactone at pyrrole D and anhydride at pyrrole C bearing a gamma-meso-bridge. In the first case, this led to the formation of substituted amides at the propionic acid residue and the introduction of hydroxy group at position 18 of the macrocycle, and, in the second case, to N-substituted cycloimides of chlorin p6. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2008, vol. 34, no. 2; see also http://www.maik.ru

Rheolytic thrombectomy: possibilities and first results.

The present study was undertaken to investigate the possibilities of using the method of rheolytic thrombectomy (hereinafter referred to as RTE) in surgical practice, and to assess its immediate outcomes in treatment of thromboses of arteries and veins of the lower extremities, as well as transjugular intrahepatic portosystemic shunts (hereinafter referred to as TIPS). We have gained experience in carrying out a total of 33 rheolytic thrombectomies with the help of the system JET 9000 (R) using the Xpeedior catheter in a total of thirty-one 43-to-87-year-old patients. Twenty-four interventions were performed for acute thromboses of arteries and shunts of the lower limbs, five - in patients presenting with floating thrombi in the inferior vena cava, and four operations were carried out in patients diagnosed with thrombosis of the segment after TIPS. In the group of the patients with thromboses of the arteries of the lower limbs (n=19), in 16 patients RTE resulted in restoration of >50% of the arterial lumen. In three patients of the same group, we managed to restore the lumen by only 50% and less. In the group of patients with thromboses of the shunts (n=5), RTE with a successful angiographic outcome was performed in three patients. In yet another patient, the lumen was restored only by 50%, and in a further one patient, the lumen of the shunt we failed to restore. Nineteen patients underwent a total of 13 balloon angioplasties (BA), 4 stenting interventions, and 2 regional thrombolytic procedures. Two patients after RTE and V A were subjected to postdilatational endarterectomy. In one patient RTE from the shunt was supplemented with plasty of its proximal anastomosis with a synthetic patch. In two patients, RTE was complicated by embolism of the deep femoral artery. In the group consisting of five patients diagnosed with floating thrombi of the inferior vena cava, a successful outcome was observed only in two. In patients presenting with thromboses of the stems following TIPS in all the cases we managed to completely restore patency of the shunts. Later on, three patients were found to have developed rethrombosis of the shunt. In two cases after RTE, haemolysis was observed to ensue, followed by the development of acute renal insufficiency. The remote results were followed up in the group of the patients with thromboses of the arteries and shunts of the lower limbs within the terms up to 24 months. Patency of the remodelled segments was preserved in seventeen patients (77.3%), and five patients (22.7%) were subjected to amputation of the affected lower extremity. Hence, the initial experience gained in using RTE gives certain hopes in treatment of patients presenting with acute arterial and venous thromboses of various localization, owing to its due safety, minimally invasive nature, and high efficiency, especially in patients with severe accompanying pathology.