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It was shown for the first time that the treatment of winter wheat (Triticum aestivum L.) seeds with gold nanoparticles (average diameter 15.3 nm; solution concentration 20 μg/mL) increases plant tolerance to low temperature. It was found that an increase in tolerance under the influence of nanoparticles is accompanied by a number of changes depending on temperature conditions. In optimal temperature conditions, gold nanoparticles stimulated plant growth and the activity of the photosynthetic apparatus, whereas in conditions of low-temperature hardening (2°C, 7 days) they inhibited growth but maintained photosynthetic activity, contributing to the accumulation of soluble sugars (cryoprotectants) in the leaves. It is concluded that gold nanoparticles can be considered as adaptogens that increase plant tolerance to low temperatures; however, their effectiveness in this role and the subtle mechanisms of action require further study.

The aim of this study was to isolate Babesia canis soluble antigens and to investigate the effect of their conjugates with gold nanoparticles on the immunogenicity in laboratory animals.A procedure was developed for isolating and purifying B. canis antigens. The isolated culture antigen of B. canis 495 was coupled to gold nanoparticles, and the conjugate was used to immunize laboratory mice.Western blotting showed that the resultant antiserum specifically recognized the proteins of the B. canis strains isolated from naturally infected dogs. The antibody titer, the respiratory activity of peritoneal macrophages, the proliferative activity of splenocytes, and the production of cytokines were maximal when the animals were immunized with the antigen-nanoparticle conjugate emulsified in complete Freund's adjuvant. Without adjuvant, the babesial antigen was weakly immunogenic.Therefore, the use of gold nanoparticles as an antigen carrier induced a broad immune response involving both cellular and humoral responses. The antibodies raised by the proposed procedure are potentially effective at immunodetection of Babesia canis infections in dogs.

It has been demonstrated that electroacoustic analysis with polyclonal antibodies can be used for bacteriophage detection. The frequency dependences of the real and imaginary parts of electrical impedance of a resonator with a viral suspension with antibodies were shown to be essentially different from the dependences of a resonator with control viral suspension without antibodies. It was shown that ΦAl-Sp59b bacteriophages were detected with the use of antibodies in the presence of foreign virus particles. The ΦAl-Sp59b bacteriophage content in the analyzed suspension was ~1010–106 phages/mL; the time of analysis was no more than 5 min. The optimally informative parameter for obtaining reliable information was the change in the real or imaginary part of electrical impedance at a fixed frequency near the resonance upon the addition of specific antibodies to the analyzed suspension. It was demonstrated that the interaction between bacteriophages and antibodies can be recorded, offering good prospects for the development of a biological sensor for liquid-phase identification and virus detection.

Functionalized gold nanoparticles (GNPs) with controlled geometrical and optical properties have been the subject of intense research and biomedical applications. This review summarizes recent data and topical problems in nanomedicine that are related to the use of variously sized, shaped, and structured GNPs. We focus on three topical fields in current nanomedicine: (1) use of GNP-based nanoplatforms for the targeted delivery of anticancer and antimicrobial drugs and of genes; (2) GNP-based cancer immunotherapy; and (3) combined chemo-, immuno-, and phototherapy. We present a summary of the available literature data and a short discussion of future work.

The changes in the electro-acoustic parameters of cell suspension due to the interaction of cells with bacteriophages both in a pure. culture and in the presence of extraneous microflora were investigated. It has been found that the specific changes in the electroacoustic parameters of cell suspension under the action of bacteriophage occur only in microbial cells which are sensitive to the bacteriophage studied. It has been established that a sensor unit allows of distinguishing a situation when the bacterial cells are infected with specific bacteriophages of the control experiments and a situation with no introduction of infection. An approximate criterion of the presence of specific interactions of bacteriophages and cells in suspension was developed. In accordance with this criterion the change in electrical impedance of the sensor unit must not be less than - 1%. In control experiments a standard microbiological technique, plating the cells infected with bacteriophages on solid nutrient medium, was used. For the first time the possibility of using the method of electroacoustic analysis for determination of a spectrum of lytic activity of bacteriophages was shown. The results obtained may be used for development of a new express method for determining the sensitivity to bacteriophages of the microbial cells.

The main results of studying the synthesis, growth mechanisms, and optical properties of gold nanorods published in the last 5–8 years are briefly reviewed. Hydrosols of gold nanorods with variable axial ratios are synthesized in the micellar solution of ionic surfactants by sead-mediated growth procedure using the stage of particle separation in the glycerol concentration gradient. Results of synthesis in systems containing one surfactant, albeit with different Ag/Au molar ratios and different amounts of gold seeding particles, agree with the published data. It is shown that, in the case of the mixture of two surfactants, the Ag/Au ratio is an efficient controlling parameter of the synthesis of nanorods with large axial ratios. The extinction and differential light scattering, spectra dynamic light scattering, and the depolarization of laser light scattering at 90° are used for the optical control of synthesis. Three fractions are observed in separated samples. One of these fractions is characterized by the only short wavelength plasmon resonance at 570 nm corresponding, in agreement with the published data, to cubic particles. Measurements of the extinction spectra of nanorods in water-glycerol mixtures reveal higher sensitivity of the longitudinal plasmon resonance to the dielectric environment relative to the transverse resonance. It is shown theoretically and experimentally that the relative shift of plasmon resonance is proportional to the relative increment of refractive index of the surrounding medium. To calculate optical properties of nanorods, we employed a model of cylinders with semispherical ends (s-cylinders) corresponding to the shape of real particles and admitting the exact solution by the T-matrix method with a computational burden that is an order of magnitude lower than that used in the discrete dipole method. The set of dependences of the longitudinal resonance wavelength on the axial ratio of different-thickness particles complies with our data and published measurements. Theoretical and experimental values of depolarization ratio I VH/I VV for nanorods and nanospheres with different sizes prepared with both citrate (15–46 nm) and original thiocyanate (90 nm) reduction of HAuCl4 are compared. It is shown that the depolarization parameter of light scattered by a nanorod suspension can exceed the theoretical limit (1/3) for common dielectric particles. The measured 10%-depolarization ratio for 90-nm spheres was far beyond the set of “size-depolarization” measurements for 15–46-nm-dia particles prepared by the citrate method and is indicative of the improved spherical morphology of 90-nm particles. This assumption was confirmed by TEM data, which also revealed both the presence of a noticeable amount of nanorods with a large axial ratio and “nanowires” of about the same thickness. A new analytic calibration for determining the diameter of spherical particles (5–100 nm) by the spectral position of the sol extinction maximum is proposed.

Azospirillum brasilense cells deprived of capsular exopolysaccharides completely lost their ability to bind wheat germ agglutinin (WGA) and much of their ability to attach to wheat seedling roots. The decapsulation of bacterial cells by washing them with a NaCl solution led to an increase in the relative hydrophobicity of the cell surface. The pretreatment of wheat seedling roots with N-acetyl-D-glucosamine (GlcNAc) or the GlcNAc-containing polysaccharide complexes stripped from Azospirillum cells reduced their attachment to the roots. Under the experimental conditions used (3-h incubation of wheat seedling roots with exponential-phase azospirilla), bacterial adsorption is mainly driven by the specific mechanisms attachment of the cells to the roots, whose operation is due to the capsular polysaccharide components and the WGA present on the wheat seedling roots.

Agrobacterial cells produced straight microfibrils not only when in contact with wheat seedling roots, but also when in contact with each other. After 2 h of incubation, agrobacterial cells were found to form aggregates, in which the cells were in contact either directly or through thick straight microfibrils (bridges) of an unknown composition. The majority of the microfibrils were susceptible to attack by cellulase, although some of them showed resistance to this enzyme. Like the wild-type flagellated agrobacteria, their bald mutants produced long straight microfibrils. The cell surface structures of agrobacteria were examined by labeling them immunocytochemically with colloidal gold–conjugated antibodies against O-specific lipopolysaccharides, Vir proteins, and cellulase. Agrobacterial cells treated with acetosyringone and brought into contact were found to contain subpolar and polar cell surface structures. Antibodies against the VirB2 protein were able to interact with a tuft of thin microfibrils located on one pole of the agrobacterial cell whose virgenes were induced by acetosyringone but were unable to interact with the surface structures of the agrobacterial cells aggregated in liquid medium in the absence of wheat seedlings.

This is the first study to demonstrate that the medicinal basidiomycete Lentinula edodes can reduce gold (III) ions from hydrogen tetrachloaurate (chloroauric acid) H[AuCl4] to the elementary state with the formation of spherical nanoparticles (nanospheres). When a culture was grown under submerged conditions in the presence of chloroauric acid, the appearance of an intense purple-red color of L. edodes filamentous hyphae was recorded, which indicates that gold ions were reduced to gold nanoparticles. Using transmission electron microscopy and X-ray fluorescence, we observed accumulation of colloidal gold by the fungal mycelium in the form of electron-dense nanospheres of 5 to 50 nm in diameter on the surface and inside fungal cells.

The phage mini-antibodies to bacterial cells of strain Azospirillum brasilense Sp245 were obtained and the possibility of using them for detection of microbial cells by means of a lateral field excited piezoelectric resonator was studied. It has been found that the frequency dependencies of the real and imaginary parts of the electrical impedance of the resonator loaded by the cell suspension A. brasilense Sp245 with the mini-antibodies, significantly differ from those of the resonator with the control cell suspension without mini-antibodies. The concentration limit of possible determination of the microbial cells in their interaction with the mini-antibodies is equal to 10(3) cells/ml. It has been ascertained that detection of A. brasilense Sp245 cells using the mini-antibodies is possible even in the presence of other cultures, for example, E. coli BL-Ril and A. brasilense Sp7 cells. Therefore, it has been shown for the first time that detection of microbial cells by an electro-acoustic sensor is feasible.

The electrooptical abilities of the microbial suspensions during a cells interaction with antibodies (ABs) of a different specificity have been studied on the example of the Azospirillum brasilense Sp245 cells and their interaction with the polyclonal monospecific and polyspecific antibodies. Measuring of the orientational spectra of the cells has been performed using the ELUS electrooptical analyzer. A discrete frequency set of an orienting electric field (740, 1000, 1450, 2000, and 2800 kHz) was used. It has been shown that an interaction of the polyspecific AB with the investigated cells redoubles the value of an electrooptical signal of the cells' suspension as compared with the monospecific antibodies. These findings can be used for a development a new method of microorganism detection.

Penetration of ivermectin adsorbed on the surface of colloidal gold particles or included in micelles to phagocytic immune system cells was studied. Detection of the preparation in the cells was carried out by an immunochemical method, employing miniantibodies to ivermectin obtained from a combinatory phage library and by a chromatographic method on the HPLC system "Stayer". It was found that ivermectin adsorbed on colloidal gold particles was accumulated in the cells most intensively.

An electrooptical approach was used in studies of Listeria monocytogenes-antibody binding. An electrooptical analyzer, which has been developed at the State Research Center for Applied Microbiology (Obolensk, Russia), was used as a basic instrument for electrooptical measurements. The analyzer consists of the following modules: a sample preparation module, a mixer, an AC field generator, an EO-flow cell, a microcontroller for transfer of liquid, a thermal system, an operator interface, and an image processor. The sample preparation module includes a unit for an automatic filter changing device and a hydraulic system. Since the AC electrokinetic effects depend on the dielectric properties of bioparticles, their composition, morphology, phenotype, the medium, and the frequency of applied electrical field, the electroorientational spectra were used for discrimination of different types of bacteria, a given type being "controlled" (and identified) by the selective choice of binding agents (antibodies). The measurements were performed using a discrete set of frequencies of the orienting electric field (10, 100, 250, and 500 kHz). During biospecific interactions, an antibody is bound to the microorganism, causing a change in the dielectric properties of the microorganism-antibody complex, and the electrooptic signal reaches its maximum at 100-200 kHz. It was shown that the biospecific interactions of Listeria monocytogenes cells with anti-Listeria antibody in the presence of E. coli K-12, and A. brasilense sp7 significantly change the electrooptical signals. Thus, the determination of the presence of particular bacteria within a mixed sample may be achieved by selection and matching of antibodies specific to individual bacterium types and by comparing the spectra of bacterium in the presence and in the absence of specific binding agent (antibody).

We studied the capacity of colloidal gold for enhancing specific and nonspecific immune response in laboratory animals (rabbits, rats, and mice) immunized with antigens of various nature. The antibody titers obtained with colloidal gold as a carrier were higher as compared to the standard immunization techniques (free antigen or Freund's adjuvant). Application of colloidal gold increased nonspecific immune responses as well: lysozyme concentration in the blood, activity of the complement system proteins, as well as phagocytic and bactericidal activities. The obtained antibodies were tested by immunodot assay using gold markers. Immunization of the animals with colloidal gold conjugates with haptens as well as complete antigens was shown to induce formation of highly active antibodies without using other antigens such as complete Freund's adjuvant. In addition, antigen quantities for animal immunization with colloidal gold was by one order of magnitude lower as compared to the complete Freund's adjuvant immunization. This fact can point to direct adjuvant activity of colloidal gold.

Serum titer achieved while producing antibodies to Y. pseudotuberculosis surface antigens with the use of colloid gold as adjuvant was as high as that achieved with the use of Freund's complete adjuvant (1:10,240). Still the amount of the antigen introduced when colloid gold particles were used as adjuvant was lower by 2 orders. The study revealed that colloid gold used as antigen carrier activated the phagocytic activity of lymphoid cells.

Some optimized methods of purifying actin from animal, plant, and bacterial cells were developed. Variants of the preparation of antiactin antibodies are described which use both traditional methods of immunization and phase display technology and antigen adsorption on colloidal gold particles. The conjugates of colloidal gold with phalloidin and heavy meromyosin as well as with antibodies were proposed. It was shown that these markers make it possible to reliably identify actins of different origin by the methods of light, and electron microscopy and dot-analysis.

Agrobacterial cells produced straight microfibrils not only when in contact with wheat seedling roots, but also when in contact with each other. After 2 h of incubation, agrobacterial cells were found to form aggregates, in which the cells were in contact either directly or through thick straight microfibrils (bridges) of an unknown composition. The majority of the microfibrils were susceptible to attack by cellulase, although some of them showed resistance to this enzyme. Like the wild-type flagellated agrobacteria, their bald mutants produced long straight microfibrils. The cells surface structures of agrobacteria were examined by labeling them immunocytochemically with colloidal gold conjugated antibodies against O-specific lipopolysaccharides, Vir proteins, and cellulase. Agrobacterial cells treated with acetosyringone and brought into contact were found to contain subpolar and polar cell surface structures. Antibodies against the VirB2 protein were able to interact with a tuft of thin microfibrils located on one pole of the agrobacterial cell, whose vir genes were induced by acetosyringone, but were unable to interact with the surface structures of the agrobacterial cells aggregated in liquid medium in the absence of wheat seedlings.

Azospirillum brasilense cells deprived of capsular exopolysaccharides completely lost their ability to bind wheat germ agglutinin (WGA) and much of their ability to attach to wheat seedling roots. The decapsulation of bacterial cells by washing them with a NaCl solution led to an increase in the relative hydrophobicity of the cell surface. The pretreatment of wheat seedling roots with N-acetyl-D-glucosamine (GlcNAc) or the GlcNAc-containing polysaccharide complexes stripped from Azospirillum cells reduced their attachment to the roots. Under the experimental conditions, 3-h incubation of wheat seedling roots with exponential-phase azospirilla, bacterial adsorption is mainly driven by the attachment of the cells to the roots, whose operation is due to the capsular polysaccharide components and the WGA present on the wheat seedling roots.

Ten Azospirillum strains were serotyped using the method of cell-gold immunoblotting (dot-blot immune-overlay assay). Colloidal gold-protein A conjugate was used. Antibodies raised against the whole cells showed strain specificity and interacted mainly with carbohydrate antigens on the cell surface. Immunological identity for A. brasilense Sp 245 and Sp 107 strains was found. Cell-gold immunoblotting can be recommended for serotyping of a wide variety of bacterial strains.

Table 1. Abundance of species and morphogroups on post-eruption sandwiches (at P-vent) and pre-eruption blocks (at East Wall). Recovery date (months since 2006 eruption), deployment habitat (H=Hot, W=Warm, C=Cool), sample ID, and recovery temperature (C) are presented for each sample. ND = no temperature data recorded. Table 2. Kruskal Wallace (K-W) analysis of variation in abundance over time of prominent species colonizing sandwiches at P-vent. Table 3. Species from regional pool near P-vent that were not observed as colonists during the initial 11 years after the 2006 eruption. List was filtered from Desbruyères et al (2006) to include only species identifiable by the techniques used in this study and in the size range (macrofauna and larger), mobility category (sedentary), and thermal environment (

Table 1. Abundance of species and morphogroups on post-eruption sandwiches (at P-vent) and pre-eruption blocks (at East Wall). Recovery date (months since 2006 eruption), deployment habitat (H=Hot, W=Warm, C=Cool), sample ID, and recovery temperature (C) are presented for each sample. ND = no temperature data recorded. Table 2. Kruskal Wallace (K-W) analysis of variation in abundance over time of prominent species colonizing sandwiches at P-vent. Table 3. Species from regional pool near P-vent that were not observed as colonists during the initial 11 years after the 2006 eruption. List was filtered from Desbruyères et al (2006) to include only species identifiable by the techniques used in this study and in the size range (macrofauna and larger), mobility category (sedentary), and thermal environment (